Search

Background: Granins have been implicated in the pathophysiology of irritable bowel syndrome (IBS) in adults. We sought to determine whether fecal granins are altered in children with IBS and associated with symptoms., Methods: Children (7-12 years of age) with IBS and healthy controls (HC) kept daily pain and stool diaries for 2 weeks. Stool samples were analyzed for chromogranins A and B (CgA, CgB) and secretogranins II and III (SgII, SgIII). Children also completed psychological measures to assess anxiety, depression, somatization, and internalizing symptoms., Key Results: Fecal CgB and SgIII concentrations were higher in all the boys (IBS plus HC, n = 48) than in all the girls (IBS plus HC, n = 75) (P = 0.02 and P = 0.046, respectively). CgA and SgIII were greater in children with IBS (n = 52) vs HC (n = 69) (P = 0.01, P = 0.017, respectively). CgB and SgII did not differ between groups. In children with IBS, the number of pain episodes per week and mean daily pain rating correlated positively with all four granins. The number of stools per day correlated positively with CgB and SgII, and the percent of diarrheal stools (6 or 7 on the Bristol Scale) correlated inversely with all four granins in boys but not in girls. Fecal granins did not correlate with psychological measures., Conclusions and Inferences: As measured by fecal granins, there is evidence of neuroimmune activation in children with IBS. Granins are related to abdominal pain symptoms, stooling frequency, and stool form in children with IBS. Sex influences the fecal concentration of CgB and SgIII., (© 2018 John Wiley & Sons Ltd.)

Altered fecal levels of chromogranins (Cg) and secretogranins (Sg) are demonstrated in irritable bowel syndrome (IBS), but their role in IBS pathophysiology remains unknown. This study aimed to determine if granins are associated with bacterial composition, immune activation and IBS symptoms. Protein levels of fecal granins (CgA, CgB, SgII and SgIII) were analysed with immunoassays. Mucosal mRNA expression of granins, TPH1 and immune markers were evaluated with RT-qPCR. 16S rRNA gene sequencing was performed on fecal and mucosal bacteria. The intestinal granin profile, based on fecal protein levels and mucosal mRNA expression, could not discriminate between IBS patients (n = 88) and healthy subjects (HS, n = 33). IBS patients dominated by high fecal or mucosal granin levels, respectively, did not differ in symptom or immune profiles. Fecal-dominated and mucosal-dominated granin clusters of IBS patients and HS, demonstrated separate fecal and mucosal bacterial profiles and high fecal abundance of granins were associated with a less diverse bacterial composition and the Bacteroides enterotype. The intestinal granin profiles of IBS patients and HS are linked to the intestinal bacterial composition, diversity and enterotypes. These findings suggest that granins may be one of several host-produced factors regulating the microbiota composition of the intestine.

Background: Prostasomes are nanosized extracellular vesicles exocytosed by prostate epithelial cells. They have been assigned many roles propitious to sperm in favor of fertilization. Prostatic cancer cells can also produce and secrete extracellular vesicles., Methods: We assessed using ELISA, the surface expression of chromogranin proproteins on prostasomes and malignant extracellular vesicles of four different prostate cancer cell-lines, two hormone sensitive and two hormone refractory. We used a panel of chromogranin A and chromogranin B antibodies against peptides in-between hypothetical cleavage sites along the proproteins., Results: A diverging pattern of chromogranin peptides was apparent when comparing prostasomes and malignant extracellular vesicles indicating a phenotypical change. We also compared western blot patterns (prostasomes and malignant extracellular vesicles) for selected antibodies that displayed high absorbances in the ELISA. Western blot analyses revealed various cleavage patterns of those proproteins that were analyzed in prostasomes and extracellular vesicles., Conclusion: Chromogranins are constituents of not only prostasomes but also of malignant prostate cell-derived extracellular vesicles with different amino acid sequences exposed at the membrane surface giving rise to a mosaic pattern. These findings may be of relevance for designing new assays for detection or even possible treatment of prostate cancers., (© 2015 Wiley Periodicals, Inc.)

Background: Methods for objective evaluation of stress in animals are important, but clinically difficult. An alternative method to study the sympathetic activity may be to investigate Chromogranin A (CGA), Chromogranin B (CGB) and Secretogranin II (SG2). The aim of this study was to investigate the cross-reactivity of CGA, CGB and SG2 between man, cat and dog and to explore possibilities to measure these proteins in samples from cats and dogs., Results: Adrenal gland extracts from feline and canine species were measured by region-specific radioimmunoassays in different dilution steps to explore possible inter species cross reactivity. High cross reactivity was found for cats in the CGA17-38, CGA324-337, CGA361-372, CGB and SG2 assays. High cross reactivity was found for dogs in the CGA17-38, CGA361-372, CGB and SN assays. The method measuring the intact CGA was not useful for measurements in cats and dogs., Conclusions: Region-specific assays measuring defined parts of CGA, CGB and SG2 can be used for measurements in samples from cats and dogs. These results are promising and will allow for further studies of these proteins as possible clinical biomarkers in cats and dogs.

Background: Little is known of the importance of chromogranins (Cg) and secretogranins (Sg) in ulcerative colitis (UC). We therefore investigated fecal levels of CgA, CgB, SgII and SgIII, and their association with inflammatory activity, disease duration and medical therapy in UC., Methods: Analyses of CgA, CgB, SgII, SgIII and calprotectin in stool samples from 41 UC patients and 29 healthy controls were performed. Two stool samples, during relapse and remission, respectively, were obtained from each UC patient., Results: The levels of fecal CgA and SgII were higher in UC patients with active disease as compared to healthy controls. CgB and SgII were positively correlated with disease duration, but none of the granins were positively correlated with calprotectin, Mayo score, CRP or serum concentrations of TNF in UC patients with active disease. Also UC patients in remission had higher levels of CgA, CgB, SgII, and SgIII as compared to healthy controls. However, levels of fecal CgA, CgB, SgII and SgIII were lower during active disease relative to remission. Moreover, fecal levels of CgA and SgII were higher in UC patients in remission treated with thiopurines than in thiopurine-naïve patients in remission., Conclusion: Fecal chromogranins and secretogranins are increased in UC but are not associated with disease activity, but seem to increase with duration of the disease. Thus, fecal granins might reflect structural changes associated with chronicity of disease, or medical therapy., (Copyright © 2013 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.)

Objectives: Chromogranins (Cg) and secretogranins (Sg) are proteins ubiquitous in secretory cells of the enteric, endocrine, and immune systems, and may reflect activity of these systems. We therefore performed a hypothesis generating study to evaluate the association between fecal levels of CgA, CgB, SgII, and SgIII, with the clinical and pathophysiological phenotype of irritable bowel syndrome (IBS) patients., Methods: Analyses of CgA, CgB, SgII, SgIII, and calprotectin in fecal samples of 82 IBS patients and 29 healthy controls were performed. All IBS subjects completed validated questionnaires to assess gastrointestinal and psychological symptom severity, and underwent rectal barostat test and colonic transit time measurement., Results: IBS patients demonstrated higher levels of fecal CgA (P=0.009), SgII (P<0.001), and SgIII (P<0.001), but lower levels of CgB (P<0.001) compared with controls. SgII had good discriminative validity to positively identify IBS patients, with an area under the receiver operating characteristics (ROC) curve (AUROC) of 0.86 (95% confidence interval (CI): 0.78-0.94). SgIII and CgB both had fairly good discriminative validity to positively identify IBS patients, with an AUROC of 0.79 (95% CI: 0.71-0.87) and 0.78 (95% CI: 0.69-0.87), respectively. There were negative correlations between the colonic transit time and fecal levels of CgA (r=-0.53, P<0.001), SgII (r=-0.55, P<0.001), and SgIII (r=-0.28, P=0.03). Perceived abdominal pain was moderately associated with levels of CgA (r=0.32, P=0.004), SgII (r=0.31, P=0.006), and SgIII (r=0.24, P=0.04). Calprotectin levels were not associated with the levels of granins or with the clinical or pathophysiological phenotype of IBS patients., Conclusions: Fecal levels of Cg and Sg may be related to the underlying pathophysiology of IBS and of potential importance for symptoms of the patients. Granins also show promise to serve as future biomarkers of IBS. Further studies are needed to explore the potential role of granins in IBS patients.

Background: Different epitopes of the granin family of proteins, chromogranin (Cg) A, CgB and secretogranin (Sg) II, have been demonstrated in normal human pancreas, gastrointestinal tract, adrenal medulla and in several neuroendocrine tumours (NETs). SgIII has been recently reported in endocrine pancreas. The aim of the present study was to examine the expression of SgIII in different NETs and compare it with the expression of CgA, CgB and SgII epitopes., Material and Methods: Tissue specimens from 47 NETs were analyzed. Antibodies to CgA 250-284, CgB 244-255, SgII 172-186 (C-terminal secretoneurin) and SgIII 348-361 were used for immunostaining., Results: SgIII was expressed in 41 of 47 NETs. The expression of SgIII agreed well with that of CgA, CgB and SgII, with exceptions of phaeochromocytomas, where more CgB and SgII immunoreactive cells were observed and parathyroid adenomas, which were only stained by CgA. In rectal NETs more cells expressed SgIII than CgA., Conclusions: This is the first report on SgIII expression in various NETs. A majority of tumours studied displayed SgIII immunostaining, which indicates a functional relationship with the other granins., (Copyright © 2010 Elsevier B.V. All rights reserved.)

This review focus on neuroendocrine tumours (NETs), with special reference to the immunohistochemical analysis of granins and granin-related peptides and their usefulness in identifying and characterizing the great diversity of NET types. Granins, their derived peptides, and complex protein-processing enzyme systems that cleave granins and prohormones, have to some extent cell-specific expression patterns in normal and neoplastic NE cells. The marker most commonly used in routine histopathology to differentiate between non-NETs and NETs is chromogranin (Cg) A, to some extent CgB. Other members of the granin family may also be of diagnostic value by identifying special NET types, e.g. secretogranin (Sg) VI was only found in pancreatic NETs and phaeochromocytomas. SgIII has recently arisen as an important NET marker; it was strongly expressed in NETs, with some exceptions--phaeochromocytomas expressed few cells and parathyroid adenomas none. Some expression patterns of granin-related peptides seem valuable in differentiating between some benign and malignant NETs, some may also provide prognostic information, among which: well-differentiated NET types expressed more CgA epitopes than the poorly differentiated ones, except insulinomas, where the opposite was noted; medullary thyroid carcinomas containing few cells immunoreactive to a CgB antibody were related to a bad prognosis; C-terminal secretoneurin visualized a cell type related to malignancy in phaeochromocytomas. Further research will probably establish new staining patterns with marker functions for granins in NETs which may be of histopathological diagnostic value., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Earlier findings indicate the acrosyringium as the target for the inflammation in the chronic and intensely inflammatory skin disease palmoplantar pustulosis (PPP). The sweat gland apparatus seems to be an immune-competent structure that probably contributes to the defence of the skin. Furthermore, the sweat gland and duct may be a hitherto unrecognized neuroendocrine organ because it expresses cholineacetyl-transferase and acetylcholinesterase, nicotinic receptors, beta-adrenergic and angiotensin receptors. The aim of this study was to obtain further information about neuroendocrine properties of the sweat gland apparatus by examining the expression of common neuroendocrine markers synaptophysin and chromogranins A and B in healthy palmar skin and in PPP skin. Synaptophysin and chromogranins were expressed in the sweat glands and ducts with some variation in the pattern and intensity of the expression. In PPP skin the expression differed, being higher and lower, depending on the part of the sweat duct. Chromogranins were further expressed in the epidermis, endothelium and inflammatory cells, but its intensity was weaker in epidermis than in the sweat gland apparatus. In most cases, chromogranins in epidermis in involved PPP were weakly expressed compared to healthy controls. The presence of synaptophysin and chromogranins in palmoplantar skin may have marked neuroendocrine effects, and the palmoplantar skin is likely to have important neuroimmuno-endocrine properties. Moreover, the altered chromogranin expression in PPP skin might influence both the neuroendocrine and neuroimmunologic properties of palmoplantar skin in these patients. These results indicate important neuroendocrine properties of the palmoplantar skin.

This short review deals with our investigations in neuroendocrine tumors (NETs) with antibodies against defined epitopes of chromogranins (Cgs) A and B and secretogranins (Sgs) II and III. The immunohistochemical expression of different epitopes of the granin family of proteins varies in NE cells in normal human endocrine and non-endocrine organs and in NETs, suggesting post-translational processing. In most NETs one or more epitopes of the granins were lacking, but variations in the expression pattern occurred both in benign and malignant NETs. A few epitopes displayed patterns that may be valuable in differentiating between benign and malignant NET types, e.g., well-differentiated NET types expressed more CgA epitopes than the poorly differentiated ones and C-terminal secretoneurin visualized a cell type related to malignancy in pheochromocytomas. Plasma concentrations of different epitopes of CgA and CgB varied. In patients suffering from carcinoid tumors or endocrine pancreatic tumors the highest concentrations were found with epitopes from the mid-portion of CgA. For CgB the highest plasma concentrations were recorded for the epitope 439-451. Measurements of SgII showed that patients with endocrine pancreatic tumors had higher concentrations than patients with carcinoid tumors or pheochromocytomas. SgIII was not detectable in patients with NETs.

Much is unknown regarding the regulation of Alzheimer-related amyloid-beta protein precursor (AbetaPP)-processing in the human central nervous system. It has been hypothesized that amyloidogenic AbetaPP-processing preferentially occurs in the regulated secretory pathway of neurons. To test this hypothesis we looked for correlations of AbetaPP-derived molecules in cerebrospinal fluid (CSF) with chromogranin (Cg) derived peptides, representing the regulated secretion. Patients with Alzheimer's disease (AD, N=32), multiple sclerosis (MS, N=50), and healthy controls (N= 70) were enrolled. CSF was analyzed for the amyloid peptides Abeta1-42, Abetax-42, Abetax-40, Abetax-38, alpha-cleaved soluble AbetaPP (sAbetaPPalpha), beta-cleaved soluble AbetaPP (sAbetaPPbeta), and peptides derived from CgB and SgII (Secretogranin-II, CgC). We investigated CSF levels of the protease BACE1, which processes AbetaPP into Abeta, in relation to Cg-levels. Finally, we measured Cg levels in cell media from untreated and BACE1-inhibited SH-SY5Y human neuroblastoma cells. CSF Cg levels correlated to sAbetaPP and Abeta peptides in AD, MS, and controls, and to CSF BACE1. Cell medium from BACE1-inhibited cells had decreased CgB levels. These results suggest that a large part of AbetaPP in the human central nervous system is processed in the regulated secretory pathway of neurons.

Introduction: Chromogranin (Cg) and secretogranin (Sg) are members of the granin family of proteins, which are expressed in neuroendocrine and nervous tissue. In recent publications we have presented generation of region-specific antibodies against CgA and CgB and also development of several region-specific radioimmunoassays for measurements of specific parts of the Cgs. In this study we describe generation of antibodies against SgII, SgIII, SgV and the proconvertases PC1/3 and PC2 and development of radioimmunoassays for measurements of these proteins., Materials and Methods: Peptides homologous to defined parts of the secretogranin and proconvertase molecules were selected and synthesised. Antibodies were raised, radioimmunoassays were developed and circulating levels of the proteins in plasma samples from 22 patients with neuroendocrine tumours were measured in the assays., Results: Increased plasma concentrations were recorded in 11, 4 and 3 of the patients with the SgII 154-165 (N-terminal secretoneurin), the SgII 172-186 (C-terminal Secretoneurin) and the SgII 225-242 assays respectively. The SgIII, SgV, PC1/3 and PC2 assays failed to detect increased concentrations in any of the patients., Conclusion: Increased concentrations of SgII, especially the N-terminal part of secretoneurin could be measured in plasma from patients with endocrine pancreatic tumours and in this case this assay was quite comparable to measurements of CgA and CgB. Even though secretoneurin was not as frequently increased as CgA and CgB in patients with carcinoid tumours or pheochromocytoma it may be a useful marker for endocrine pancreatic tumours.

Chromogranins and secretogranins belong to the granin family of proteins, which are expressed in neuroendocrine and nervous tissue. In earlier publications we have described the development of region-specific antibodies against CgA and CgB. In this study we describe antibodies to SgII and SgIII and their usefulness for immunohistochemical staining. Peptides homologous to defined parts of secretogranins II and III were selected and synthesized. Antibodies were raised and immunostainings were performed on normal human pancreas. The SgII 154-165 (N-terminal secretoneurin), SgII 172-186 (C-terminal secretoneurin) and SgIII antibodies immunostained all insulin-immunoreactive cells, most of the glucagon cells and some of the pancreatic polypeptide cells. The SgII 225-242 antibody immunostained only the insulin-containing cells. None of the antibodies immunostained the somatostatin cells. This study is the first observation of the expression of SgIII in human tissues, where we show expression of SgIII in three of the four major islet cell types in human pancreas.

In this pilot study, the predictive value of Octreotide scintigraphy (Octreoscan) and/or Chromogranin-A (CgA) was investigated in patients with hormone-refractory prostate cancer treated with Octreotide acetate. In total, 20 patients with progressive disease and bone metastases entered the trial. At baseline Octreoscan, CgA, PSA, alkaline phosphates (ALP) and two self-administered questionnaires (EORTC QLQ C-30 (v3) and brief pain index) were performed and a diary of the pharmaceutical was started. The treatment consisted of Octreotide (Sandostatin LAR) acetate 30 mg intramuscular injection every month. The blood samples and questionnaires were repeated every month until 3 months. Clinical responder was defined as a patient with increased global health score more than 10 units and stable or decreased pain score without an increase in analgesic. In all, 17 patients were treated per protocol, and four were assessed as clinical responders. Six patients developed a reduction in ALP (median -26%, range -5 to -78%). All patients increased in PSA. At baseline, three patients had a negative Octreoscan and the patients with positive lesions, demonstrated uptake of low intensity. At baseline the CgA was elevated above the normal range in 15 of the patients, and during treatment five patients decreased their CgA to the normal range. Neither baseline Octreoscan nor CgA could identify the clinical reponders. A minority of patients improves their health-related quality of life. The decrease and normalization of CgA levels in five patients during therapy indicates therapeutic activity but Octreoscan and CgA could not identify clinical responders.

Chromogranin A (CgA) and its valuable complement synaptic vesicle protein 2 (SV2) are neuroendocrine (NE) markers. Post-translational processing of CgA has been reported to vary in different NE cell types and tumors, but little is known regarding the expression of various CgA epitopes and SV2 in NE pulmonary tumors. We studied the immunoreactivity to six CgA epitopes and SV2 in ten typical (TC) and ten atypical (ACT) carcinoids, five large-cell NE carcinomas (LCNEC) and five small-cell carcinomas (SCLC), also comparing the results with clinicopathological characteristics of tumors. The sequences CgA 17--38 (vasostatin), 176--195 (chromacin), 375--384 (parastatin) and 411--424 (C-terminal parastatin) and SV2 were relevant markers for the CT/ATC group, whereas the antibody to CgA 176--195 was a better marker for the LCNEC/SCLC group. An inverse correlation was found between proliferative activity and granule-related markers in the CT/ACT group, and a direct correlation in poorly differentiated tumors. The expression of granule-related markers did not correlate with hormone content or clinical characteristics of NE tumors. The expression of CgA epitopes and SV2 occurs in all NE tumors, differing between better differentiated and poorly differentiated tumors but not within the respective groups.

Introduction: The primary structure of human chromogranin B (CgB) contains 15 pairs of basic amino acids, which are potential cleavage sites for specific endogenous proteases, but also other sites in the molecule can be subjected to cleavage. Several CgB-related peptides have been identified in tissue extracts., Materials and Methods: Peptides homologous to defined parts of the human CgB molecule were selected and synthesized. Antibodies were raised and 13 specific radioimmunoassays were developed. Plasma samples from 19 patients with neuroendocrine tumors were collected and measured in all assays., Results: All region-specific assays measured circulating levels of CgB-related peptides. Only five of the assays measured high concentrations of circulating CgB and two of them correlated with that of intact chromogranin A (CgA)., Conclusion: The assays presented allow measurements of defined regions of CgB and will thus become important tools for further studies of the processing of CgB. One of the assays merit further investigations as a new marker for neuroendocrine tumors.

In a recent immunohistochemical study of pheochromocytomas, a difference was observed between benign and malignant pheochromocytomas in their expression in different parts of the chromogranin (Cg) A molecule. The purpose of the present study was to extend the investigations by including two other members of this Cg family, CgB and C. Twenty-five patients operated on for clinicopathologically benign pheochromocytomas, and four for metastasizing pheochromocytomas, were studied. Expression of the different Cg regions was studied immunohistochemically by means of region-specific antibodies: four raised against CgA epitopes, five against CgB, and two against CgC. Adrenal medulla parenchyma from three surgical adrenalectomy specimens was used as non-neoplastic control. All cells of normal adrenal medulla were immunoreactive to all 11 region-specific Cg antibodies. In the pheochromocytomas, variations in the expression pattern occurred, but no significant quantitative differences were noted between benign and malignant tumours. Nevertheless, in all four malignant pheochromocytomas, the antibodies raised against the C-terminal regions of both CgB and CgC visualised a noticeable population of large spindle-shaped tumour cells, characterised by elongated processes. This cell type occurred in all four malignant pheochromocytomas but only in one benign tumour. Their structure and immunoreactivity differed from those of the sustentacular cells in the pheochromocytoma parenchyma. The use of region-specific antibodies raised against epitopes in the C-terminal region of CgB and CgC can facilitate the diagnosis of malignant pheochromocytoma.

Neuroendocrine (NE) tumours are characterized by their capacity to synthesize, store and release hormonal products. These substances are stored in neurosecretory vesicles together with chromogranin A (CgA). The concentration of plasma CgA in patients with NE tumours is thought to reflect the degree of NE differentiation, total tumour burden and effect of medical treatment. The aim of this study was to analyse the correlation between tumour weight and plasma CgA levels as well as the influence of treatment with a long-acting somatostatin analogue (octreotide) using nude mice with xenografted human ileal carcinoid tumours. There was a correlation between tumour weight and plasma CgA levels in all animals (p < 0.00001). In octreotide-treated mice, plasma CgA levels were significantly reduced versus untreated animals (p = 0.037). In conclusion, this study demonstrates that plasma CgA levels are closely correlated to tumour burden, and that plasma CgA is well suited for monitoring the clinical course and outcome of treatment in patients with NE tumours.

Chromogranin B (CgB), a major member of the chromogranin/secretogranin family of catecholamine storage vesicle secretory proteins, plays both intracellular (vesiculogenic) and extracellular (prohormone) roles in the neuroendocrine system, and its biosynthesis and release are under the control of efferent sympathetic nerve traffic ("stimulus-transcription coupling"). To explore the role of heredity in control of CgB, we conducted a genome-wide linkage analysis of CgB release in 12 extended CEPH (Centre d'Etude du Polymorphisme Humain) pedigrees. Region-specific radioimmunoassays were used to measure five CgB fragments in plasma: CgB1-16, CgB312-331, CgB439-451, CgB568-577, and CgB647-657. Substantial heritability, as measured by h2r, was observed for three of the fragment concentrations, CgB312-331, CgB439-451, and CgB568-577, which yielded h2r estimates ranging from 0.378 (P = 0.002) to 0.910 (P < 0.0000001). Variance-component genome-wide linkage analysis with 654 microsatellite markers at 5 cM spacing identified a major quantitative trait locus for CgB312-331 on chromosome 11q24-q25 with a maximum multipoint LOD score of 5.84. Significant allelic associations between markers in the region and CgB levels were also observed. Although the 2-LOD confidence interval for linkage did not include the CgB locus itself, known trans-activators of the CgB gene promoter, or prohormone cleaving proteases, examination of positional candidate loci within this region yielded novel and plausible physiological candidates for further exploration. Allelic variation in this region may thus influence effects of sympathetic outflow on target organs in humans.

This study investigated the role of the secretory granule proteins, secretogranin II (SgII) and chromogranin A (CgA), in the differential secretion of FSH and LH from LbetaT2 mouse gonadotroph cells. Exogenous activin, which synergises with GnRH, is essential for the release of FSH from these cells, but also has stimulatory effects on LH and enhances GnRH-induced LH secretion. Two experiments are reported. In experiment 1, cultures were supplemented with activin (0-50 ng/ml), with and without a daily 1 h treatment of 10 nM GnRH, for 3 days. Protein secretion and mRNA levels were measured. In experiment 2, cells were treated with activin (50 ng/ml) alone, a daily 1 h treatment of 10 nM GnRH, or a combination of both for 6 days. In addition, cells exposed to activin+GnRH for 3 days were subsequently left untreated or given activin or GnRH alone for a further 3 days for comparison with cells maintained in activin+GnRH for 6 days. Protein secretion, intracellular protein and mRNA levels were measured. FSH secretion was stimulated, dose dependently, by activin and this effect increased synergistically in the presence of GnRH. The close correlation between secreted and intracellular FSH and FSHbeta mRNA levels was maintained in cells that had undergone treatment withdrawal after previous exposure to activin+GnRH, but there was no correlation between FSH and the granins. These results are consistent with the view that FSH released in response to activin/GnRH is constitutively secreted via a granin-independent pathway. SgII secretion mirrored the GnRH-induced secretion of LH, but was unaffected by activin, which stimulated LH secretion and had a detrimental effect on CgA mRNA transcription. This confirms previous observations that the LH released in response to GnRH is co-released with SgII via a regulated, granin-dependent pathway, and, in addition, suggests that activin may stimulate LH secretion through a constitutive, granin-independent pathway.

Introduction: The primary structure of human chromogranin A (CgA) not only contains 10 pairs of basic amino acids, which are potential cleavage sites for specific endogenous proteases, but also other sites in the molecule can be subjected to cleavage. Several CgA-related peptides have been identified in tissue, and many of the biological effects attributed to CgA seem to be mediated by these peptides., Materials and Methods: Peptides homologous to defined parts of the human CgA molecule were selected and synthesised. Antibodies were raised, and 11 specific radioimmunoassays were developed. Plasma samples from 20 patients with neuroendocrine tumours were collected and measured in all assays., Results: All assays measured circulating levels of CgA-derived peptides. Only four of the assays measured concentrations that correlated with that of total CgA. However, concentrations of the individual CgA-related peptides were generally lower than the concentration of total CgA. Different neuroendocrine tumours seem to process CgA differently. The ratio between a given region-specific assay and total CgA is inversely correlated to tumour activity., Conclusion: The assays presented allow measurements of defined regions of CgA and will thus become important tools for further studies of processing of CgA.

The chromogranin/secretogranin proteins are costored and coreleased with catecholamines from secretory vesicles in chromaffin cells and noradrenergic neurons. Chromogranin A (CHGA) regulates catecholamine storage and release through intracellular (vesiculogenic) and extracellular (catecholamine release-inhibitory) mechanisms. CHGA is a candidate gene for autonomic dysfunction syndromes, including intermediate phenotypes that contribute to human hypertension. Here, we show a surprising pattern of CHGA variants that alter the expression and function of this gene, both in vivo and in vitro. Functional variants include both common alleles that quantitatively alter gene expression and rare alleles that qualitatively change the encoded product to alter the signaling potency of CHGA-derived catecholamine release-inhibitory catestatin peptides.

Introduction and Aims: To get more insight into the differentiation patterns of pancreatic islet neuroendocrine cells and granules during ontogeny, the expression and localization of chromogranin A (CgA), chromogranin B (CgB), synaptophysin, and insulin were ultrastructurally studied with the immunogold technique in porcine and human pancreatic islet neuroendocrine cells., Methodology and Results: In porcine pancreas at early fetal stage, CgA was visualized throughout the immature granules in all neuroendocrine cells. Later, CgB also was expressed with the same pattern in most granules in all types of cells. In neonatal islets, CgA was localized in the periphery of immature alpha- and beta-cell granules and throughout the matrix of delta-cell granules; CgB was distributed throughout the matrix of these granules. In adult islets, alpha-cell granules stored CgA in the halo and CgB in both the core and the halo, beta-cell granules stored both CgA and CgB in their cores, and in delta-cell granules, both substances were mixed throughout the matrix. In all ontogenetic stages, synaptophysin was demonstrated in all cell types and granules. Insulin was expressed in early fetal cells of both pigs and humans, and colocalization with CgA, CgB, and synaptophysin was demonstrated., Conclusion: The early expression of CgA and synaptophysin may reflect a role at early fetal stages, and the individual localization of CgA and CgB upon differentiation indicates individual functions.

Chromogranin (CgA) has been shown to be an excellent marker for neuroendocrine tumours. There are now three commercial assays on the market. We wanted to compare the usefulness of the different kits in a clinical situation. We have thus measured CgA in 77 patients and compared the results from the different methods. CgA was measured with three different commercial kits according to the recommendations from the manufacturers (CGA-RIA CT; CIS bio international, Gif-sur-Yvette cedex, France, DAKO Chromogranin A ELISA kit; DAKO A/S, Glostrup, Denmark and CgA; EuroDiagnostica, Malmö, Sweden). The sensitivity and specificity differed between the different kits. The CIS kit showed a sensitivity of 67% and a specificity of 96%. The sensitivity and specificity were both 85% for the DAKO kit and 93% and 88% respectively for the EuroDiagnostica assay. We have concluded that CgA is an important tumour marker for all neuroendocrine tumours. However, different analytical properties of the respective kits give different performances, a fact that must be taken into consideration when comparing results from different clinical studies. A recognised international standard for CgA would be a step on the way to harmonisation, but antibody selection and construction of the assays will probably still influence the results.

The expression of various chromogranin A (CgA) peptide fragments was examined with region-specific antisera in benign and malignant pituitary tumors. Analysis of the proconvertases responsible for proteolytic processing of CgA, prohormone convertase 1/3 (PC1/3), and PC2 was also performed. Adenomas were studied using tissue microarrays, and a larger tissue section of a subset of the prolactin (PRL) adenomas was used to compare to the tissue microarray analysis. Carcinomas were analyzed using larger tissue sections. There were differences in CgA proteolytic products detected between the functional (PRL, adrenocorticotropic hormone [ACTH], and growth hormone tumors and the nonfunctional (gonadotroph and null cell) tumors, with the former group expressing lower levels of many peptides. These differences were most notable in the PRL adenomas and carcinomas in which the region-specific antisera against vasostatin I and vasostatin II detected these fragments in the lowest percentage of tumors and/or had the weakest immunoreactivity. The CgA peptide fragment detected by CgA 176-195 (chromacin) antiserum was expressed by the highest percentage of most functional and nonfunctional benign and malignant pituitary tumors. ACTH carcinomas (n = 3) were more strongly immunoreactive compared to the ACTH adenomas. These results show that there is differential expression of CgA peptide fragments and PC1/3 among different types of pituitary tumors and that ACTH pituitary carcinomas have higher levels of immunoreactive CgA peptide fragments compared to ACTH adenomas. This study also shows the utility of tissue microarrays in the analysis of a large group of tumors with regionspecific antisera.

We studied the immunoreactivity of 12 different region-specific antibodies to the chromogranin A (CgA) molecule in the various neuroendocrine cell types of the human gastrointestinal (GI) tract by using double immunofluorescence techniques. These staining results were compared with others obtained with a commercial monoclonal CgA antibody (LK2H10). G (gastrin)-cells showed immunoreactivity to virtually all region-specific antibodies, but with varying frequency. Most intestinal EC (enterochromaffin)- and L (enteroglucagon)-cells were immunoreactive to the antibodies to the N-terminal and mid-portion of the CgA molecule, whereas the EC-cells in the stomach reacted with fewer region-specific antibodies. D (somatostatin)-cells reacted to the CgA 411-424 antibody and only occasionally showed immunoreactivity to the other CgA antibodies. A larger cytoplasmic area was stained with the antibodies to CgA 17-38 and 176-195 than with the other antibodies tested. These differences in staining pattern may reflect different cleavage of the CgA molecule in different cell types and at different regions of the GI tract.

The granin proteins secretogranin II (SgII) and chromogranin A (CgA) are commonly found associated with LH and/or FSH within specialised secretory granules in gonadotroph cells, and it is possible that they play an important role in the differential secretion of the gonadotrophins. In this study we have examined the regulation of the biosynthesis and secretion of SgII and CgA, in relation to LH secretion, in the LbetaT2 mouse pituitary gonadotroph cell line. Three experiments were carried out to investigate the effects of oestradiol (E2) and dexamethasone (Dex) in the presence and absence of GnRH (experiment 1), differing GnRH concentrations (experiment 2) and alterations in GnRH pulse frequency (experiment 3). In experiment 1, exposure to E2, Dex or E2+Dex, either with or without GnRH treatment, resulted in increased LH secretion. Steroids alone had no effect on LHbeta mRNA levels, but in the presence of GnRH LHbeta mRNA levels were increased in Dex- and E2+Dex-treated cells. GnRH receptor (GnRH-R) mRNA levels were up-regulated by Dex and E2+Dex, but were unaffected by GnRH. There were no steroid-induced changes in SgII or CgA mRNA, but increased levels of CgA mRNA were observed after GnRH treatment in cells cultured in the presence of Dex. In experiment 2, increasing concentrations of GnRH resulted in increases in LH secretion that were inversely dose-dependent. No changes in LHbeta, GnRH-R or SgII mRNA levels were observed, but there were dose-dependent increases in CgA mRNA levels. In experiment 3, GnRH was given as either 1 pulse/day or 4 pulses/day for 3 days. Both pulse regimes resulted in increased LH, SgII and CgA secretion compared with controls during the first 15 min pulse on day 3. Exposure to GnRH at 4 pulses/day increased LH and SgII secretion compared with controls during all 4 pulses, but secretion of both proteins was reduced during pulses 2-4 compared with pulse 1. CgA secretion also increased due to GnRH in pulse 1, but was decreased by GnRH treatment during pulse 2, and unchanged by GnRH during pulses 3 and 4. Total daily secretion of LH and SgII from cells given 1 pulse/day of GnRH increased compared with controls on all three treatment days, while total CgA secretion increased in response to GnRH on days 2 and 3 only. Intracellular levels of SgII, but not LH, decreased after GnRH treatment. In contrast, intracellular CgA was increased, but only after 4 pulses/day of GnRH. Levels of LHbeta, but not SgII, mRNA were increased by both pulse regimes, while CgA mRNA levels increased after 1 pulse/day of GnRH. These results indicate that there is a close correlation between the GnRH-stimulated release of LH and SgII from LbetaT2 cells, suggesting that SgII may have an influential role in the regulated secretion of LH, possibly by inducing LH aggregation to facilitate trafficking into secretory granules. CgA secretion does not appear to be closely associated with that of LH, but CgA expression does appear to be regulated by GnRH, which may indicate involvement in the control of LH secretion, possibly by influencing the proportion of LH in the different types of secretory granules.

Chromogranin (Cg) B is an acidic glycoprotein present in neuroendocrine tissue. The sequence shows several dibasic amino acid positions susceptible to proteolytic cleavage. The purpose of this study was to elucidate the expression of CgB epitopes in the human endocrine pancreas. Tissue sections of six human pancreata were immunostained with 16 different region-specific antibodies to the CgB molecule, using double immunofluorescence techniques. The CgB epitope pattern varied in the four major islet cell types. B (insulin)-cells expressed immunoreactivity to all region-specific antibodies. The antibodies to the N-terminal and mid-portions of CgB showed moderate immunoreactivity, the C-terminal antibodies weak. A (glucagon)-cells were reactive only to the N-terminal and mid-portion antibodies but, after microwave pretreatment, to all antibodies, whereas D (somatostatin)-cells expressed only the sequence CgB 244-255 and a subpopulation CgB 580-595. PP (pancreatic polypeptide) cells were immunostained with antibodies between CgB 1-417 and a few with CgB 580-593. The fragment CgB 244-255 was expressed in all four cell types. The cause of these differences may be cell-specific cleavage or masking of the molecule, but varying translation of CgB mRNA is also possible. The extent to which these epitopes reflect fragments having biological functions remains to be evaluated.

Antibodies to six specific regions of the chromogranin A (CgA) molecule were used to study their immunoreactivity in human neuroendocrine (NE) tumors. Tissue specimens from endocrine pancreatic tumors (n = 14), duodenal carcinoids (n = 2), bronchial carcinoids (n = 5), ileal carcinoids (n = 5) appendix carcinoids (n = 2), medullary thyroid carcinomas (n = 6), parathyroid adenomas (n = 2), and pheochromocytomas (n = 8) were analyzed. The results showed that the NE tumor types expressed varying numbers of CgA fragments. A variation in frequency of the expression of immunoreactive cells was sometimes seen also within the same tumor type. The midportion fragment CgA 176-195 (chromacin) was the only fragment expressed in all tumors. Benign and malignant tumors expressed different patterns, being especially true of insulinomas and pheochromocytomas. These findings suggest that region-specific antibodies to CgA fragments can be used as a diagnostic tool for the characterization of NE tumors.

Background: Serum chromogranin A (CgA), a marker of neuroendocrine neoplasia, increases during profound gastric acid inhibition, possibly reflecting the trophic effect of gastrin on the enterochromaffin-like (ECL) cells., Aims: This study investigated the clinical value of serum CgA as a screening test for gastric fundic enterochromaffin-like (ECL) cell hyperplasia during acid-suppressive therapy., Method: A consecutive series of 230 dyspeptic patients referred for upper gastrointestinal endoscopy was investigated in a cross-sectional design. They were 154 patients on continuous medium-term (6 weeks to one year) or long-term (longer than one year) acid inhibition with either proton pump inhibitors (PPIs, n = 117) or histamine2-receptor antagonists (H2RAs, n = 37) for gastro-oesophageal reflux disease, and 76 nontreated subjects, with normal endoscopic findings (control group). Fasting blood samples were analysed for gastrin and CgA. Gastric biopsy specimens (oxyntic mucosa) were examined for histological evaluation of gastritis (Sydney classification) and of ECL cell hyperplasia (Solcia classification)., Results: Serum CgA levels correlated positively with serum gastrin, following a quadratic function (r = 0.78, P < 0.0001). Elevated serum CgA values during long-term acid inhibition correlated with the presence and severity of fundic ECL cell hyperplasia. Multivariate analysis identified hypergastrinaemia (P < 0.0001), duration of acid inhibition (P < 0.0001), H. pylori infection (P = 0.008), ECL cell hyperplasia (P = 0.012), and body gland atrophy (P = 0.043) as independent predictors of elevated serum CgA. In subjects on long-term acid inhibition (n = 123), serum CgA was equally sensitive but more specific than serum gastrin for the detection of ECL cell hyperplasia (sensitivity, 91.3% for both; specificity, 73% vs. 43%, P < 0.0001)., Conclusions: During long-term gastric acid inhibition, serum CgA levels reflect the presence and severity of fundic ECL cell hyperplasia. Serum CgA is therefore a useful screening test for gastric ECL cell proliferative changes within this context.

We studied the immunoreactivity of 12 different region-specific antibodies to the chromogranin A (CgA) molecule in the four major neuroendocrine cell types of the human pancreas by using double immunofluorescence techniques. The antibodies raised to the N-terminal and midportions of CgA showed, on the whole, stronger immunoreactivity than did the C-terminal antibodies, with a few exceptions. Often the immunoreactivity was stronger in glucagon cells. Insulin cells expressed immunoreactivity to all region-specific antibodies, but glucagon cells were nonreactive to two antibodies. Somatostatin cells reacted only with the C-terminal antibodies (amino acid sequences CgA 411-424), while PP cells were stained with four CgA region-specific antibodies between amino acid sequences 63-195. The cause of these differences may be that the CgA molecule is cleaved, partly masked, or partly translated from CgA mRNA. Microwave treatment improved only the staining with the CgA 361-372 antibodies, which indicates that masking is not the sole or entire cause. Our findings may indicate that the CgA molecule is cleaved in different ways in the various pancreatic endocrine cell types, giving rise to a variety of biologically functional fragments.

Background: The polymorphic enzyme CYP2C19 is of importance for the metabolism and effects of omeprazole during short-term treatment., Aim: To investigate the relationship between CYP2C19 genotype and the effects of long-term omeprazole treatment., Material and Methods: A total of 180 patients with acid related disorders were genotyped for wild type and mutated CYP2C19 alleles by allele-specific PCR amplification. Gastrin and chromogranin A were assessed by radioimmunoassays, and pepsinogen I and H. pylori serology were assessed by ELISA methods., Results: In 108 of the patients, who received a single dose of 20 mg omeprazole, there was no difference in gastrin and chromogranin A concentrations between the three CYP2C19 genotypes. In 72 patients on long-term treatment (> 1 year) with 20 mg omeprazole daily, serum gastrin as well as plasma chromogranin A concentrations (mean +/- s.e.) were both about threefold higher in the wild type/mutated (52.1 +/- 7.6 pM and 7.3 +/- 1.3 nM (n=19), respectively) compared to wild type/wild type (14. 7 +/- 0.9 pM and 2.5 +/- 0.1 nM (n=52), respectively; both comparisons P=0.0001). In a single mutated/mutated patient on long-term treatment, both gastrin and chromogranin A were high (88 pM and 13.7 nM, respectively). Serum pepsinogen I concentration was significantly lower in wild type/mutated (n=19) patients on long-term treatment, compared with the corresponding wild type/wild type (n=49) group (147 +/- 19 microg/L vs. 193 +/- 12 microg/L, P=0. 04)., Conclusion: Patients with one (and probably also with two) mutated CYP2C19 allele(s) on long-term treatment with omeprazole had significantly affected serum gastrin and pepsinogen I and plasma chromogranin A concentrations compared with patients with two normal alleles. This indicates that changes in gastric mucosal morphology during omeprazole treatment might be dependent upon the degree of the individual's capacity to metabolize omeprazole.

Chromogranin A (CgA) and chromogranin B (CgB) are acidic proteins stored in and released from hormone granules in endocrine and neuroendocrine tissue. The chromogranins are postulated to serve as pro-hormones to generate biologically active peptides, which may influence hormonal release and vascular functions or have antibacterial functions. Although N-terminal and C-terminal regions show some species amino acid homology, the chromogranins as a whole display considerable interspecies differences, which prevents their use in comparative studies of biological functions. We present four new radioimmunoassays for the measurement of defined N-terminal regions of CgA and CgB. A new radioimmunoassay for measurement of intact bovine CgA has also been developed. With these assays and two previously published ones, we have compared the cross-reactivity of chromogranins from man, cattle, sheep, goat, pig and horse and compared adrenomedullar content and serum levels of CgA from these species. We have also studied the influence of peptide concentrations and the ionic strength of the mobile phase on molecular weight estimations. Assays with antibodies directed against the N-terminal parts of CgA and CgB showed sufficient interspecies cross-reactivity to allow comparative quantification of the circulating levels in man, cattle, sheep, goat, pig and horse. Assays measuring the intact human or bovine CgA were not suitable for comparative purposes in samples from sheep, goat, pig and horse. Molecular interactions between vasostatin immunoreactive material and intact bovine CgA were demonstrated in gel permeation studies, suggesting that conclusions about the degree of N-terminal processing from elution profiles should be made with caution. Reliable interspecies comparison of chromogranins is difficult, but measurements with region-specific assays may be helpful to study concentrations of chromogranins and chromogranin-related peptides.

In the endocrine pancreas, chromogranin-A and pancreastatin have been suggested to inhibit islet insulin secretion, whereas chromogranin-B has not been studied in this context. Furthermore, a putative effect by chromogranins on IAPP secretion is unknown. We aimed to elucidate the endogenous effect of chromogranin-A, pancreastatin and chromogranin-B on islet insulin and IAPP secretion from pancreatic NMRI mouse islets. In acute experiments, there was a tendency towards an increase in insulin release, which became more manifest after a 48-h exposure. Moreover, 48 h exposure to chromogranin-B antiserum resulted in a significant increase in (pro)insulin synthesis. Neither antibodies against chromogranin-A nor pancreastatin had any effect on islet hormone secretion. None of the antibodies tested had any effect on islet IAPP or insulin content. We suggest that chromogranin-B released from islets may have an autocrine inhibitory effect on islet IAPP and insulin secretion. Our data imply a regulatory role of chromogranin-B in islet IAPP and insulin secretion.

Most neuroendocrine tumors produce and secrete a multitude of peptide hormones and amines. Some of these substances cause a specific clinical syndrome: carcinoid, Zollinger-Ellison, hyperglycemic, glucagonoma and WDHA syndrome. Specific markers for these syndromes are basal and/or stimulated levels of urinary 5-HIAA, serum or plasma gastrin, insulin, glucagon and vasoactive intestinal polypeptide, respectively. Some carcinoid tumors and about one third of endocrine pancreatic tumors do not present any clinical symptoms and are called 'nonfunctioning' tumors. Therefore, general tumor markers such as chromogranin A, pancreatic polypeptide, serum neuron-specific enolase and subunits of glycoprotein hormones have been used for screening purposes in patients without distinct clinical hormone-related symptoms. Among these general tumor markers chromogranin A, although its precise function is not yet established, has been shown to be a very sensitive and specific serum marker for various types of neuroendocrine tumors. This is because it may also be elevated in many cases of less well-differentiated tumors of neuroendocrine origin that do not secrete known hormones. At the moment, chromogranin A is considered the best general neuroendocrine serum or plasma marker available both for diagnosis and therapeutic evaluation and is increased in 50-100% of patients with various neuroendocrine tumors. Chromogranin A serum or plasma levels reflect tumor load, and it may be an independent marker of prognosis in patients with midgut carcinoids., (Copyright 2000 S. Karger AG, Basel)

Background: It has been hypothesized that a lesion in the neuronal circuits of thalamus might contribute to the symptoms in schizophrenia. It has also been suggested that impaired synaptic transmission is an important component of the pathophysiology of schizophrenia. In the present study we assess the synaptic integrity of thalamus by means of examining the protein levels of: (1) synaptophysin, a membrane bound protein of small synaptic vesicles, and (2) chromogranins, a family of soluble secretory proteins stored and released from the secretory large dense-core vesicles., Methods: The brains of 9 patients with schizophrenia and 9 age-matched control subjects were studied. The levels of synaptophysin and chromogranins were measured by radioimmunoassays., Results: The amount of synaptophysin in the left thalamus was significantly decreased (p = .036) in the schizophrenic group (2655 +/- 605 nmol synaptophysin/mg total protein) compared to the control group (3248 +/- 827 nmol synaptophysin/mg total protein). There were no differences between the groups in the levels of chromogranins, nor in the levels of synaptophysin of the right thalamus., Conclusions: These findings indicate defect synaptic function in the left thalamus of patients with schizophrenia. This may be the cause of a reduction of synaptic terminals or a defect limited to certain structures of the synapse, namely the small presynaptic vesicles.

Plasma chromogranin A (CgA) has been claimed to be a sensitive marker for neuroendocrine tumors, but its role in the early diagnosis of multiple endocrine neoplasia type 1 (MEN 1) pancreatic endocrine tumors has not been evaluated. We measured CgA in 36 patients with MEN 1, of whom 9 lacked pancreatic involvement, 20 had biochemical evidence of pancreatic endocrine tumors, and 7 displayed radiologically detectable pancreatic tumors. CgA was also analyzed in 25 patients with sporadic pancreatic endocrine tumors, 39 subjects with inflammatory bowel disease, 7 patients harboring nonendocrine pancreatic disease, and 19 healthy controls. Four of 9 of the MEN 1 patients without pancreatic involvement had elevated CgA. Furthermore, 60% with biochemically unequivocal tumors and all with a radiologically visible tumor showed elevations. All 25 patients with sporadic pancreatic endocrine tumor had increased CgA, as had 28% of patients with inflammatory bowel disease and 57% with nonendocrine pancreatic disease. Mean day to day CgA variation was 29% (range, 0-113%) in the neuroendocrine tumor patients and 21.0% (range, 0.0-47%, within reference range) among healthy controls. In summary, nonendocrine diseases may cause elevation of CgA, and its spontaneous variation can be considerable. Plasma chromogranin A is the most sensitive of the basal markers for neuroendocrine tumors, but cannot replace other established measures when screening for early pancreatic involvement in MEN 1.

The granins (secretogranins/chromogranins) are a family of soluble proteins stored and released from the secretory large dense-core vesicles of the synapse. Schizophrenia is a common and devastating brain disorder. Although the aetiology of schizophrenia is unknown, data are accumulating that synaptic disturbance or damage may be of importance. The objective of this study was to compare the levels of chromogranin A, B and C in the cerebrospinal fluid (CSF) of patients with schizophrenia and healthy controls. CSF chromogranin levels were measured by RIA in 33 subsequent admissions of patients with psychotic disorder and in 31 healthy controls. The levels of CSF chromogranin A (11.8+/-3.0 vs 14.8+/-4.8 nmol/l, P=0.004), chromogranin B (3.4+/-0.49 vs 3.7+/-0.58 nmol/l, P=0.02), but not chromogranin C (70.2+/-15.7 vs 65.3+/-20.4 pmol/l, P=0.29) were lower in the schizophrenic patients than in the healthy controls. These data indicate that two widespread constituents of large dense-core vesicles, i.e. chromogranin A and chromogranin B, are altered in chronic schizophrenic patients.

Background: Serum chromogranin A (CgA) is regarded as a reliable marker of neuroendocrine proliferation. We previously described increased serum CgA levels during short-term profound gastric acid inhibition., Aim: To investigate serum gastrin and CgA levels in dyspeptic patients during continuous medium- (6 weeks to 1 year), or long-term (1-8 years) gastric acid suppressive therapy., Patients and Methods: 114 consecutive dyspeptic patients referred for upper gastrointestinal endoscopy were enrolled in a cross-sectional, case-control study [62 patients on continuous antisecretory therapy, either with proton pump inhibitors (n = 47) or H2-receptor antagonists (H2RA) (n = 15) for gastro-oesophageal reflux disease with or without Barrett's oesophagus or functional dyspepsia, and 52 age- and sex-matched patients without medical acid inhibition and with normal endoscopic findings (control group)]. Omeprazole doses ranged from 20 mg to 80 mg daily and ranitidine from 150 mg to 450 mg daily. Fasting serum CgA and serum gastrin levels were measured by radioimmunoassay (reference values: serum CgA < 4.0 nmol/L; serum gastrin < 85 ng/L)., Results: Fasting serum CgA levels positively correlated with serum gastrin in the entire study population (r = 0. 55, P = 0.0001). Median serum CgA values were higher in patients treated with a proton pump inhibitor than H2RA [2.8 (2.0-5.9) nmol/L vs. 2 (1.9-2.3) nmol/L, P < 0.002] and controls [2.8 (2.0-5.9) nmol/L vs. 1.8 (1.5-2.2) nmol/L, P < 0.0001) and did not differ between patients treated with H2RA or controls. Serum gastrin and CgA levels in patients on proton pump inhibitor therapy positively correlated with the degree and duration of acid inhibition. Patients on long-term proton pump inhibitor therapy had significantly higher fasting serum gastrin and CgA than those on medium-term proton pump inhibitor therapy [127 (73-217) ng/L vs. 49 (29-78) ng/L, P < 0.0001 and 4.8 (2.8-8) ng/L vs. 2.1 (1.9-2.6) ng/L, P < 0.001]. No such relation was found in patients on medium- vs. long-term H2RA. Overall, patients with positive Helicobacter pylori serology had higher serum gastrin and CgA levels than those with negative H. pylori serology [51 (27-119) ng/L vs. 27 (14-79) ng/L, P = 0.01, 2.4 (1.9-3.4) nmol/L vs. 2.0 (1.7-2.5) nmol/L, P = 0.05]., Conclusions: During long-term continuous proton pump inhibitor treatment, serum gastrin and CgA levels are significantly elevated compared to H2RA treatment and nontreated dyspeptic controls. H. pylori infection seems to affect gastric ECL cell secretory function. Increased serum CgA values during long-term profound gastric acid inhibition could reflect either gastric enterochromaffin-like cell hyperfunction or proliferative changes.

Because of their water-soluble properties, chromogranins (CGs) and chromogranin-derived fragments are released together with catecholamines from adrenal chromaffin cells during stress situations and can be detected in the blood by radiochemical and enzyme assays. It is well known that chromogranins can serve as immunocytochemical markers for neuroendocrine tissues and as a diagnostic tool for neuroendocrine tumors. In 1993, large CGA-derived fragments have been shown to be excreted into the urine in patients with carcinoid tumors and the present study deals with the characterization of the post-translational modifications (phosphorylation and O-glycosylation) located along the largest natural CGA-derived fragment CGA79-439. Using mild proteolysis of peptidic material, high performance liquid chromatography, sequencing, and mass spectrometry analysis, six post-translational modifications were detected along the C-terminal CGA-derived fragment CGA79-439. Three O-linked glycosylation sites were located in the core of the protein on Thr163, Thr165, and Thr233, consisting in di-, tri-, and tetrasaccharides. Three phosphorylation sites were located in the middle and C-terminal domain, on serine residues Ser200, Ser252, and Ser315. These modified sites were compared with sequences of others species and discussed in relation with the post-translational modifications that we have reported previously for bovine CGA.

Background: Type 1 gastric carcinoids are associated with hypergastrinaemia and chronic atrophic gastritis, type 2 occur in patients with multiple endocrine neoplasia type 1 combined with Zollinger-Ellison syndrome, and type 3 lack any relation to hypergastrinaemia. Type 1 tumours are usually benign whereas type 3 are highly malignant., Aims: To identify possible tumour markers in patients with gastric carcinoids., Patients/method: Nine patients with type 1, one with type 2, and five with type 3 were evaluated with regard to symptoms, hormone profile, and prognosis., Results: Plasma chromogranin A was increased in all patients but was higher (p < 0.01) in those with type 3 than those with type 1 carcinoids. All patients with type 3 carcinoids died from metastatic disease, but none of the type 1 patients died as a result of their tumours. One type 1 patient with a solitary liver metastasis received interferon alpha and octreotide treatment. Nine months later, the metastasis was no longer detectable. She is still alive eight years after diagnosis, without recurrent disease. This represents the only reported case of foregut carcinoid with an unresectable liver metastasis that seems to be have been cured by biotherapy., Conclusions: Plasma chromogranin A appears to be a valuable tumour marker for all types of gastric carcinoid. Combination therapy with interferon alpha and octreotide may be beneficial in patients with metastasising type 1 gastric carcinoids.

Co-localization of chromogranin (Cg) A, B, and C has been studied in different neuroendocrine cell types in histologically normal mucosa from human gastrointestinal tract (corpus, antrum, duodenum, ileum, and colon) using single-, double-, and triple-immunofluorescence stainings. Virtually all enterochromaffin (EC) cells contained CgA, and those in the luminal two thirds of the antral mucosa and villi of small intestine often also contained CgB. A few EC cells in the duodenal crypts contained CgC. Most gastrin cells harbored both CgB and CgA, although rather more CgB than CgA, but some gastrin cells contained all three types, i.e., also CgC. Some CCK cells also contained all three chromogranins. Enteroglucagon cells in the duodenal villi contained CgA and some CgB. CgA (but not B or C) was found in some secretin, GIP, enteroglucagon/peptide YY, and neurotensin cells. A few somatostatin cells contained CgA but neither CgB nor CgC. CgA and C were found mainly in the basal cell region, whereas CgB occurred more diffusely throughout the cytoplasm. This varying distribution suggests that not all secretory granules contain CgA, or that CgB may occur in a nongranular form. The varying composition of the different chromogranins may reflect their complex functional roles in the widespread neuroendocrine system.

Background: It is not known whether plasma chromogranin analysis could be a complement to histology for detection and grading of gastric fundic mucosal endocrine cell proliferation in hypergastrinemic (type-A) atrophic gastritis., Methods: Gastric biopsy sections (body and antrum) from 43 patients with type-A gastritis (9 with gastric carcinoid) were examined for density and micronodules of argyrophil endocrine cells. Fasting blood samples were analyzed for chromogranin A and B, gastrin, and somatostatin., Results: All patients with carcinoid and 17 of the 34 without carcinoid had micronodules in the gastric fundic mucosa. The median plasma chromogranin A concentration was 5.7 (3.5-40.0) nmol/l in patients with carcinoid, 4.5 (3.0-9.5) nmol/l in patients with micronodules, and 3.7 (0.8-6.0) nmol/l in patients without micronodules. Overall, chromogranin A concentrations correlated to endocrine cell densities in the fundic mucosa (r = 0.64, P < 0.001) and to gastrin concentrations (r = 0.71, P < 0.001). Plasma somatostatin and chromogranin B concentrations did not differ significantly between the groups., Conclusion: In type-A gastritis, analysis of plasma chromogranin A may be a useful complement to histology in estimating the endocrine cell mass. Moreover, subclinical type-A gastritis may be a source of error when chromogranin A analysis is used in the search for neuroendocrine neoplasia.

Specific assays for measurements of circulating chromogranin (Cg) A, CgB, CgC and pancreastatin (Ps) have recently been developed. The aim of the present study was to investigate the usefulness of these markers in diagnosing and following the effects of treatment of patients with phaeochromocytoma, and to compare the results with those concerning other biochemical markers. CgA was elevated in 19/21 (90%), CgB in 17/21 (81%), Ps in 9/21 (43%) and neuropeptide Y in 9/21 (43%) of the patients. Urinary noradrenaline was increased in 19/21 (90%) and urinary adrenaline in 17/19 (89%) of the patients. All patients had increased levels of either urinary catecholamines or plasma chromogranins. In one patient levels of CgA, CgB and Ps were measured at frequent intervals before, during and after surgery. The CgA level fell to normal shortly after the tumour was removed, whereas the CgB level decreased towards normal over the course of several days. Significant correlation was observed between the contents of CgA and CgB in the tumour tissue and the plasma levels of CgA and CgB respectively. We conclude that CgA and CgB are sensitive circulating markers for phaeochromocytoma and that measurements of both urinary catecholamines and plasma chromogranins improve the diagnostic sensitivity. Furthermore, measurements of CgA may be useful in assessing the radicality of surgery in the early postoperative period.

The aim of the present study was to examine the correlation between the immunohistochemical findings and the serum markers for neuroendocrine (NE) cells in patients with carcinoma of the prostate. Preoperative serum values of chromogranin A (CgA), chromogranin B (CgB), pancreastatin (Pst), neuron-specific enolase (NSE), and prostatic specific antigen (PSA) were determined in 22 patients. The tissue specimens were obtained by a palliative transurethral resection of the prostate (TURP) because of urinary outflow obstruction. Immunohistochemistry was performed by using antibodies against CgA, CgB, NSE,.serotonin, thyroid-stimulating hormone (TSH), and somatostatin. Tumor cells with NE differentiation were found in 91% of the cases. No patient had elevated serum values of NSE, despite the presence of NSE-positive tumor cells in 77% of the tumors. Neither did CgB in serum correlate with the immunohistochemical findings. Elevated serum values of CgA were found in 59% of patients. A positive correlation between the number of CgA-staining cells and the serum values of CgA was found, as seven out of eight patients with groups of CgA-positive tumor cells had elevated serum values of CgA. We conclude that CgA, in contrast to NSE, CgB, and Pst, seems to be a useful serum marker in predicting the extent of NE differentiation in prostatic tumors.

Placenta is a neuroendocrine organ, and we therefore wanted to study the occurrence of the general neuroendocrine marker chromogranin A (CgA) and its split product pancreastatin. CgA and pancreastatin-like immunoreactivity (PST-LI) were determined by ELISA and RIA methods, respectively, in homogenates from term placentas, sera from pregnant women, nonpregnant women, umbilical cords, and in amniotic fluids. In placental homogenates, the mean level of CgA was 7.1 +/- 8.6 pmol/g wet wt (mean +/- SD), whereas PST-LI was not detectable. CgA immunoreactivity was demonstrated by immunofluorescence studies of isolated trophoblasts and decidual cells from term placentas. In trophoblasts, CgA was colocalized with human chorionic gonadotropin (hCG) and human placental lactogen. By Northern blotting, a distinct band corresponding to CgA messenger RNA (mRNA) was demonstrated in the placental cell line, whereas, in placental homogenates, a mRNA band of a slightly larger size was found. Median CgA level in maternal sera at term tended to be higher (median: 469 pmol/L, range 61-980 pmol/L, P < 0.1) than at 6-11 weeks (286 pmol/L, 61-653 pmol/L) or in sera from nonpregnant women (306 pmol/L, 204-469 pmol/L). In umbilical cord sera, median CgA level was significantly higher (898 pmol/L, 102-2245 pmol/L, P < 0.05) than in term sera. Median serum level of PST-LI was significantly higher at term (38 pmol/L, 0-131 pmol/L) than at 6-11 weeks (9 pmol/L (0-85 pmol/L, P < 0.05), than in nonpregnant women (6 pmol/L, 0-52 pmol/L, P < 0.05), and in umbilical cord sera (12 pmol/L, 0-76 pmol/L, P < 0.05). In amniotic fluid, median CgA value was significantly higher at term (1163 pmol/L, 714-1673 pmol/L) than at 14-17 weeks (551 pmol/L, 82-980 pmol/L, P < 0.01), whereas median level of PST-LI was significantly higher at 14-17 weeks (32 pmol/L, 6-97 pmol/L) than at term (0 pmol/L, 0-15 pmol/L, P < 0.01). To our knowledge, this is the first report describing the presence of CgA and PST-LI in placenta and amniotic fluid and the occurrence CgA mRNA in placental tissue and in a placental cell line. The presence of CgA in placenta may indicate a physiological role in pregnancy.