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Previous studies have shown that amylase levels are reduced significantly in the pancreas and parotid gland of diabetic rats and that insulin reverses this effect and increases the secretory protein levels. In the pancreas, these changes in amylase protein levels are accompanied by parallel changes in amylase mRNA levels. In the present study, the effects of diabetes and subsequent insulin treatments on contents (per cell) of amylase protein and its mRNA in parotid glands were compared in rats rendered diabetic with an injection of a beta-cell toxin, streptozotocin (STZ). Both amylase protein and its mRNA contents were reduced significantly in diabetic rats, compared with control rats, and this reduction was reversed following insulin injections of diabetic rats. In insulin-injected diabetic rats, amylase protein contents increased before a detectable increase in amylase mRNA levels was seen. The mRNA contents of a non-secretory protein, actin, did not change during diabetogenesis or subsequent insulin treatments. The reductions in parotid contents of amylase and its mRNA in diabetic rats and the reversal of these changes by insulin are similar to those changes that occur in the pancreas under the same conditions. However, the magnitude of these changes in parotid glands was much smaller than in the pancreas, and the effect of insulin on amylase mRNA synthesis was not as immediate as in the latter gland.

Essential fatty acid (EFA) deficiency has been proposed as a major pathogenic mechanism for cystic fibrosis (CF) and EFA-deficient animals have been proposed as an animal model for CF. In the present study, the elemental composition and ultrastructure of the acinar cells of the submandibular and parotid gland of the pancreas of EFA-deficient rats were investigated by X-ray microanalysis and electron microscopy. The effects of EFA-deficiency were compared to changes in these exocrine glands in chronically reserpine-treated rats, an established animal model for CF. EFA-deficiency did not cause any significant changes in the elemental composition of the acinar cells of the submandibular or parotid gland, or of the pancreas. The changes in elemental composition induced by reserpine treatment were only slightly modified by EFA-deficiency, mainly towards normalization. EFA-deficiency resulted in the presence of abnormal, electron translucent, zymogen granules in the parotid gland and in a reduction of the number of zymogen granules in pancreatic acinar cells. Since EFA-deficiency in rats only causes minor changes in structure and elemental composition of salivary glands and pancreas, and does not potentiate the effect of chronic reserpine treatment on these tissues, it is concluded that EFA-deficiency is likely to be of minor importance in the exocrine gland disturbances in CF.

Isoelectric focusing of human salivary proteins with carrier ampholyte-isoelectric focusing systems requires prior desalting and concentration of samples, a procedure which is time-consuming and requires relatively large volumes of samples. By contrast, immobilized pH gradient gels are more tolerant to salt loads. Thus pretreatment of samples consists only of centrifugation prior to isoelectric focusing. If larger loads (greater than 50 micrograms) are required, the samples may be concentrated by lyophilization and reconstitution in a smaller volume of water or by dialysis against 30% w/v polyethylene glycol. Immobilized pH gradient polyacrylamide gels (incorporating a hybrid carrier ampholyte system) of two pH ranges (pH 4-9 and pH 3.5-5.0) have been used to separate the proteins in human parotid saliva. The effects of urea on focused patterns were studied; in pH 4-9 gels it gave improved resolution of protein bands, whereas in pH 3.5-5.0 gels it prevented protein precipitation. The salivary proteins were then visualized by staining with Coomassie Brilliant Blue G-250 or a silver procedure. Using the latter, 25-30 well-resolved bands were formed on a pH 4-9 gel loaded with 20 micrograms of proteins. The method offers considerable advantages compared with carrier ampholyte-isoelectric focusing.

Normal concentrations of trace elements in parotid saliva, supernatant- and sediment-mixed saliva, plasma, and hair were determined in 278 healthy adults grouped as young (18-29 y), middle-aged (30-64 y), and elderly (65-93 y). Age-related increases (p less than 0.05) were observed in concentrations of zinc in the supernatant of mixed saliva and parotid saliva, copper in plasma, and protein in all fractions of saliva studied. Concentrations of zinc in salivary sediment and plasma did not vary with age. Age-related decreases (p less than 0.05) were found in concentrations of magnesium in mixed-saliva supernatant, copper in salivary sediment, and zinc and copper in hair. Males had higher concentrations of zinc in plasma (p less than 0.05) and of copper in sediment (p less than 0.01) than did females but lower amounts of copper in plasma and of protein in parotid saliva (p less than 0.05). Concentrations of zinc in saliva were not correlated with those in plasma or hair. Copper in mixed-saliva supernatant was positively associated with concentrations in plasma but negatively related to concentrations in hair.

The water release from the sublingual, parotid and submandibular glands of male and female rats was analyzed by thermal analysis in order to detect the total water content and types. Different types of water, which are increasing from the sublingual to the parotid gland, were found and the relative distribution appeared to be a function of the bond energy of water to glandular components. In addition, evidence of a sexual dimorphism in the rat sublingual gland was demonstrated.

A method is described for separation of ionic detergent-solubilized proteins by ion-exchange chromatography. This method has been developed for purification of two phosphoproteins (Mr 19,000 and 30,000) from 32Pi-prelabeled, isoproterenol-stimulated rat parotid tissue and is based on the observation that, in the presence of urea and Nonidet-P40, ionic detergent-solubilized proteins can be adsorbed by ion exchangers according to their own charge. After adsorption, proteins were eluted with a stepwise gradient of NaCl in a urea-containing buffer. By the procedure described, the 30 kDa phosphoprotein was freed from other 32P-labeled substances; and it was identified as ribosomal protein S6 that was phosphorylated at some serine residues. The method is generally applicable and especially suited for preliminary purification of hydrophobic proteins subjected to analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Immunoreactive vasoactive intestinal peptide (VIP) and substance P (SP) were studied in parotid, submaxillary and sublingual glands of the rat. The concentration of VIP was highest in the submaxillary gland and lowest in the parotid gland. The concentration of SP was highest in the parotid gland; it was at, or below the limit of detection in the sublingual gland. In the parotid gland the total amounts of VIP and SP were reduced by 95% after parasympathetic denervation (section of the auriculo-temporal nerve). In the submaxillary gland the total amounts of the peptides were unchanged after parasympathetic decentralization (section of the chorda-lingual nerve). In this gland the total amount of SP was reduced by 92% and that of VIP by 50%, when the chorda tympani nerve fibres were cut deep into the hilum. Cutting the nerve fibres at the hilum left the total amounts of the peptides unchanged in the submaxillary gland, whereas in the sublingual gland the total amount of VIP was reduced by 70%. Sympathetic denervation did not reduce the total amounts of the peptides. Duct ligation caused gland atrophy. In the parotid gland the total amounts of VIP and SP were reduced by 40%. In the submaxillary gland the same percentage reduction occurred with regard to SP; however, the total amount of VIP was reduced by 99%. The VIP- and SP-containing nerve fibres reach the salivary glands by the parasympathetic nerves. In both submaxillary and sublingual glands a certain fraction of VIP originates within the glands.

The concentraiton of zinc in parotid saliva was estimated by flameless atomic absorption spectrophotometry. As small a sample as 5 to 10 mul of whole paratid saliva can be analyzed quickly and reliably, without special sample handling and with littleinterference from other ions normally found in saliva. Parotid salivary zinc concentration in 34 subjects with normal taste acuity was 51 plus or minus 14 ppb(parts per billion)(mean plus or minus 1 S.D.); parotid salivary zinc concentration in 47 subjectswith idiopathic hypogeusia was 10 plus or minus 6 ppb (mean plus or minus 1 S.D.) which is significantly lower than that in normal subjects (p lessthan 0.001). This technique is a usual method by which to evaluate parotid salivary zinc, particulary inrelationship to problems of taste, appetite, and nutrition.

Two new genetic protein polymorphisms (CON 1 and CON 2) were identified in parotid saliva. Genetic polymorphisms of salivary CON 1 (concanavalin A) and CON 2 proteins are determined by autosomal inheritance of one expressed (dominant) and one unexpressed (recessive) allele for each gene. Autosomal inheritance is supported by studies in 26 families including 105 children for CON 1 and 23 families including 95 children for CON 2. Gene frequencies determined for randomly collected salivas from 134 whites, 79 Chinese, and 74 blacks are as follows: for whites, CON 1+ = 0.396 and CON 1- = 0.604, CON 2+ = 0.034 and CON 2- = 0.966; for Chinese, CON 1+ = 0.580 and CON 1- = 0.420, CON 2+ = 0 and CON 2- = 1; for blacks, CON 1+ = 0.581 and CON 1- = 0.419, CON 2+ = 0.007 and CON 2- = 0.993. Both CON 1 and CON 2 proteins, transferred from SDS gels to nitrocellulose, react with concanavalin A. The CON 1 and CON 2 proteins react with antisera prepared to proline-rich proteins (PRP), and the CON 1 and CON 2 proteins have isoelectric points greater than pH 8.5. In randomly collected salivas, the CON 1 protein shows a strong association with Ps proteins, and the CON 2 protein shows a strong association with the PmF protein. On the basis of association data, PmS and CON 2 genes may be outside markers in a linear arrangement of the three genes, PmS, PmF, and CON 2. There is strong evidence for linkage of CON 1 and CON 2 to the SPC (salivary protein gene complex), CON 1 to Ps (15 families, lod score at theta = 0 is 6.77), CON 2 to PmF (7 families, lod score at theta = 0 is 5.93), and CON 2 to G1 (5 families, lod score at theta = 0 is 3.91). In addition to immunologic reactions with the CON 1 and CON 2 proteins, antisera to PRP show extensive immunologic reactions with many other salivary proteins when tested by immunoblotting on nitrocellulose. Some of these proteins were previously identified PRP (proline-rich proteins) that are determined by different PRP loci.

Lysozyme and lactoferrin, substances of the non-specific defense system of the salivary glands, were studied in normal human parotid glands of neonates and adults using the immunoperoxidase method. To our knowledge, the immunohistochemical detection and distribution of lysozyme and lactoferrin in neonate parotid glands have not been previously reported. In neonate parotid glands, a monotonous positive reaction for lysozyme was found in the acini, in the intercalated ducts and in a few cells of large ducts. On the contrary, lysozyme was observed mainly in the intercalated ducts of the adult parotid glands. Three staining patterns for lactoferrin were found in neonate parotid glands. The first pattern was identical to that of lysozyme in neonates, the second was similar to that of lactoferrin in adults, and in the third extremely few acinar and intercalated duct cells were positive. In adult parotid glands, lactoferrin was detected in groups of acini and intercalated ducts and rarely striated duct cells. In adult parotid glands, our findings are discussed in correlation with those of other investigators. The results of our study indicate that lysozyme and lactoferrin have an important role in the defense mechanism of neonate parotid gland. There is also a distinct immunohistochemical difference between neonate and adult parotid gland. Since it is known that there is a morphological differentiation of the parotid gland postnatally, it is presumably suggested that an immunohistochemical differentiation also occurs.

1. The administration of crude venom of the parotoid glands of the toad Bufo ictericus ictericus to the in situ (via abdominal vein) or isolated heart of this anuran causes both chronotropic and inotropic effects. 2. While under action of parotoid venom, the heart of the animal is insensitive to vagus nerve stimulation. 3. This blocking of vagal action is dose dependent and it is suggested that it results from a functional antagonism between the venom constituents and the acetylcholine liberated by the nerve endings on stimulation. 4. The venom constituents probably involved in this antagonism are catecholamines (adrenaline and noradrenaline), tryptamine derivatives (serotonin and bufotenidin) and genins (bufagin and bufotoxin), possibly also ATP. 5. Adrenaline, noradrenaline and serotonin, or a mixture of the three, mimic, at least partially, the blocking of vagal action caused by crude venom. 6. The blocking action of crude venom can be prevented by previously or simultaneously adding acetylcholine to the infused crude venom. This prevention is dose dependent. 7. The blocking action persists in the boiled venom and in the material dialysed from crude venom.

Genomic DNA fragments bearing proline-rich protein (PRP) genes expressed specifically in hamster parotid glands have been isolated and characterized. Complete exonic sequences as well as intronic and a considerable portion of the flanking sequences are reported for a PRP gene, H29. H29 is interrupted by three intervening sequences, with consensus splice junctions, and it likely encodes the acidic hamster PRP Hp43a. Exceedingly high homology of the 5'-untranslated region and the sequence encoding the signal peptide is observed with other PRPs of all species studied. Significant homology was also detected among the repetitive sequences of the mature acidic PRPs from human, mouse, hamster, and rat. This conservation of the internal repeats of the PRPs suggested that proline-rich protein gene evolution involved intragenic duplication of internal repeats and gene duplication and conversion. Both hamster and mouse PRP genes (H29 and mouse proline-rich protein gene, respectively) share considerable sequence similarity in the 5'-flanking regions for about 100 base pairs upstream. The remainder of the upstream sequences were heterologous except for three oligonucleotide regions with 60-70% sequence conservation. These three regions are thought to be involved in the regulation of the tissue-specific PRP gene induction.

Acid-ethanol extracts of homogenates from the parotid and submaxillary salivary glands of normal and streptozocin-induced diabetic adult male mice were investigated for insulin-like material. Extracts of both the parotid and submaxillary glands contained insulin-like immunoreactivity. The values were 156 +/- 72 ng/g wet tissue in the parotid and 104 +/- 36 ng/g wet tissue in the submaxillary gland. Fractionation of this material on Sephadex G-50 (superfine) columns revealed a single peak corresponding to the elution volume of isotopically labeled insulin. Isolated fat cells were stimulated by these extracts to convert [14C]glucose to 14CO2. This effect was blocked by preincubation with anti-insulin serum. It was observed with the avidin-biotin immunocytochemical technique that both the parotid and submaxillary glands of adult male mice possess a population of cells containing an insulin-like material. After intraperitoneal injection of streptozocin there was a marked decrease of insulin-like material extractable from both the parotid and submaxillary glands. However, this beta-cell cytotoxic agent did not completely destroy the salivary cells containing the insulin-like material. These data suggest that both the parotid and submaxillary salivary glands may be extrapancreatic sources of insulin in mice.

The morphology and composition of isolated acinar cells from the enlarged parotid glands of rats treated chronically with DL-isoproterenol were investigated and compared with isolated acinar cells from parotids of control untreated rats. Changes similar to those observed in parotid acinar cells from patients with cystic fibrosis were demonstrated.

Isoproterenol (ISO)-induced amylase release from rat parotid slices was increased by the addition of methoxamine to either a normal or a calcium (Ca)-free medium. The potentiating effect of methoxamine was completely blocked by the addition of phentolamine, irrespective of whether the slices were incubated in the normal or the Ca-free medium; and the effect also disappeared after prolonged preincubation (60 min) of the slices in the Ca-free medium. Both verapamil and procaine reduced methoxamine-induced amylase release, but only verapamil blocked the stimulating effect of methoxamine in the normal medium. ISO-induced accumulation of cyclic AMP in the slices was unaffected by methoxamine or phenylephrine. The results suggest a possibility that the potentiating effect of methoxamine on ISO-induced amylase release may be independent of the presence of extracellular Ca and the increased accumulation of cyclic AMP in the tissue is unnecessary.

Using an indirect immunoferritin method, the subcellular distribution of acidic proline-rich proteins (MPRP) in the acinar cells of the macaque parotid and submandibular glands was defined. MPRP was found in the "spherule" substructure of the secretory granules as well as in specific Golgi transfer vesicles and in vesicles budding from the Golgi apparatus. The data suggest that the acidic proline-rich proteins of the primate Macaca fascicularis are synthesized and packaged by conventional exocrine mechanisms. In addition, these proteins appear to be packaged and transferred to the secretory granules of parotid and submandibular gland acinar cells as discrete aggregates that remain as a separate "spherule" area in the secretory granules.

Rat saliva contains a cobalamin-binding protein that binds cobalamin as well as cobinamide. The protein binds cobalamin with an affinity constant of 8 X 10(10) l X mol-1, and it binds cobalamin over a more narrow pH range (pH 7.5-10) than does human haptocorrin. It has a Stokes radius of 2.45 nm as compared to the Stokes radius of 4.50 nm for human haptocorrin. Upon isoelectricfocusing it dissociates into four strong bands with pI between 7 and 8, while human haptocorrin dissociates into acid isoproteins. Since human haptocorrin binds to concanavalin A while rat haptocorrin does not, we suggest that rat haptocorrin lacks carbohydrate. The substance concentration of rat saliva haptocorrin is 0.04-12.9 nmol X l-1 (median 7.5 nmol X l-1, n = 9) for control animals. After stimulation with isoproterenol, a beta-adrenergic agent, the substance concentration is 46.4-96.6 nmol X l-1 (median 69.7 nmol X l-1, n = 8). Immunohistochemical studies show haptocorrin in the secretory acini of the submandibular and parotid glands of the rat. In the human submandibular gland, the protein is detected both in the mucous secretory acini and in the intercalated ducts.

To our knowledge, there are currently no reports in the literature that discuss the fine structure of the striated ducts of the human parotid gland. Papillary cystadenoma lymphomatosum (Warthin's tumor) is a benigh neoplasm found almost exclusively in the parotid gland that represents about 16% of all neoplasms of the gland. This neoplasm is believed to arise from the striated and/or excretory ducts, but there are contradictions with regard to the proposed origin and the cellular composition of some Warthin's tumors. Tissue was obtained at the time of surgery and examined ultrastructurally and cytochemically for the localization of alkaline phosphatase and adenosine triphosphatase. Myoepithelial cells were found ultrastructurally and cytochemically on the proximal aspect of the striated duct, with their cell bodies situated at the junction of the striated and intercalated ducts. Two Warthin's tumors were observed with cells that were structurally and cytochemically similar to myoepithelial cells.

A chromatographic procedure for purification of the proteins in human parotid saliva has been developed. The eluates of a Sephadex G-150 and two ion exchange columns have been analyzed simultaneously by several physical and chemical tests; these include three optical properties of proteins, assays for neutral sugars, sialic acid and zinc, and disc gel electrophoresis. The ratios of the different variables have been used to determine the homogeneity and complexity of the protein distribution in the various peaks of the chromatographic eluates. By chromatographic methods, it has been possible to purify a glycoprotein with unusual staining characteristics and amino acid composition. Glycoproteins with similar properties comprise a major portion of the proteins in parotid saliva and appear to constitute a family of related proteins which differ in molecular size, carbohydrate and sialic acid content, and electrophoretic mobility. The fractionation of several enzymes in parotid saliva is also reported.

The allelically determined human salivary proteins, Ps 1 and 2, were purified on sodium dodecyl sulfate gels, eluted, and compared by limited proteolysis with Streptomyces griseus protease VI, Bacillus subtilis protease VII, and Staphylococcus aureus protease V8. Prior dansylation of the Ps isoproteins facilitated visualization of the peptides. Digestion patterns indicate considerable homology between the Ps isoproteins and support the conclusion [Azen, A. E., and Denniston, C. (1980). Biochem. Genet. 18:483] that there is an actual molecular weight difference between them. Further, the results suggest that this difference owes to an extension of the Ps 2 chain at one of its ends.

A new method for the determination of ionized calcium in parotid saliva utilizing an automatic ionized calcium analyzer (Orion Biomedical Model Space-Stat 20) was evaluated. The method showed good precision with a relative standard deviation of 2.9--3.8 per cent in the range 0.20--0.79 mmol . l-1 after 226 duplicate measurements. Mean recovery was 94.9% in the range of 0.6--1.8 mmol. l-1. Bovine mucin was found not to interfere with the calcium electrode. Differences in sodium concentration, ionic strength and pH between the standard solutions and samples caused systematic errors. These were corrected using experimentally derived formulas. The influence of pH on the concentration of ionized calcium was studied in 13 parotid saliva samples. A non-linear relationship ranging between 32 and 84% of the total calcium concentration was found.

A rapid and sensitive assay for peptidases acting on the C-terminal hexapeptide sequence of the neuropeptide substance P is described. The radiolabelled substrate, N alpha-[125I]desaminotyrosyl-substance P (6-11) is easily prepared by coupling commercially available radioiodinated Bolton-Hunter reagent with substance P (6-11). Peptidase activity is determined by quantitative separation of the degradation products from the intact substrate on small QAE-Sephadex columns. The assay has been used to measure degradation of the substrate by rat parotid and diencephalon slices. The peptidase activity in the latter system was inhibited by substance P and substance P fragments and was sensitive to metal chelators and thiol reagents.

Although low concentrations of total polyribosomal RNA from porcine parotid glands or rat pituitary cells in culture (GH3) isolated by standard dodecylsulphate/phenol, chloroform extraction techniques can direct the incorporation of radiolabeled amino acids into proteins using a cell-free protein-synthesizing system derived from wheat germ embryos, higher concentrations inhibit the translation of endogenous wheat germ mRNA, or added rabbit globin mRNA or polyribouridylic acid. This inhibitory activity is separated from poly(A)-rich RNA by oligo(dT)-cellulose chromatography. The inhibitory activity appears to reside in a heat-stable protein since it is inactivated by incubation with various proteases but not by DNAase I, pancreatic ribonuclease, alkaline hydrolysis, or treatment with formamide. Specificity of the inhibition is suggested since the inhibitory fraction prepared from GH3 cells also inhibits protein synthesis in a cell-free protein-synthesizing system derived from porcine parotid gland, while the inhibitory fraction prepared from porcine parotid gland has no inhibitory activity in this homologous system. Radioiodination and dodecylsulphate/polyacrylamide gel electrophoresis reveal several protein bands, the most prominent with an apparent molecular weight of 78 000.

Sodium handling by stimulated human parotid glands was evaluated in male and female subjects across the adult life-span. Young adults secreted more sodium in saliva than their middle-aged and older counterparts. To assess the extent of ductal sodium reabsorption on sodium levels calculated to be present in parotid primary secretory fluid, the relationship between sodium output and parotid saliva flow rate was analyzed. Results are inconsistent with a simple two-stage model of salivary secretion.

Two ultrasensitive methods were employed to determine the effect of repeated in vivo stimulation with isoproterenol on the protein composition of parotid acinar cells. Silver staining showed electrophoretic banding pattern changes in a wide range of cellular proteins during and after multiple injections of the beta-adrenergic agonist. Photo-affinity labeling with [32P]-N3-cyclic AMP showed the disappearance and eventual return (after discontinuation of the injections) of the cellular cyclic AMP-binding proteins as measurable cellular components. These findings indicate that major translation-associated changes may occur in target cell protein composition both during and after hormonal stimulation.

Using the indirect immunofluorescent technique with anti-somatostatin serum, the distribution of scattered cells in the duct system of submandibular glands in the Monkey, Macaca irus has been assessed. In both males and females, these cells are located only in some portions of the duct system, e.g. striated ducts and excretory ducts. No immunoreactive cells were observed in the intercalated ducts or in secretory endpieces. The lymphatic node constantly adjacent to the submandibular gland did not contain immunoreactive cells. In the parotid glands, no immunoreactive cells to antisomatostatin immuneserum were ever observed.

Acidic proline-rich proteins were localized histologically by means of the indirect immunoperoxidase technique in the acinar cells of parotid and submandibular gland sections of both man and Macaca fascicularis. These proteins were also identified as constituents of the long term in vivo-formed acquired pellicle on human tooth surfaces employing the same immunoperoxidase technique. Immunological quantitation of proline-rich proteins in whole and parotid saliva of 42 subjects indicates the presence of high concentrations in parotid secretions varying between 19-80 mg%, while their levels in whole saliva are significantly lower, ranging between 0-18 mg%. The concentrations of these proteins in whole saliva exhibited a negative correlation with plaque accumulation (r = -0.464) and gingival index scores (r = -0.576).

Actomyosin was partially purified from rat parotid cells dispersed by collagenase digestion and found to possess different solubility characteristics from that from (undispersed) rat parotid tissue. This is attributed to the decrease in vascular contamination effected by the isolation of parotid cells, yielding a non-muscle actomyosin [Adelstein, Conti, Johnson, Pastan & Pollard (1972) Proc. Natl. Acad. Sci. U.S.A. 69, 3693-3697]. Myosin light-chain kinase was partially purified from dispersed rat parotid cells by calmodulin affinity chromatography and shown to be activated by Ca2+-calmodulin. The calmodulin content of dispersed rat parotid cells was shown to be 6.50 +/- 0.59 ng of calmodulin/micrograms of rat parotid-cell protein (mean +/- S.E.M.), as determined by the activation of purified bovine brain phosphodiesterase by heat-treated extracts of dispersed rat parotid cells.

Methotrexate (MTX) was injected intraperitoneally at a dose of 15 mg/kg into adult rats daily for three consecutive days. When compared with saline-injected, ad libitum-fed rats or pair-fed saline-injected rats, MTX decreased unstimulated parotid gland weight, RNA content, and amylase content. RNA content was also decreased in submandibular glands. The parotid and submandibular gland outputs of sodium and chloride, but not that of potassium, were decreased following MTX injection. Ductal perfusion demonstrated decreased net efflux of sodium and chloride from the excretory duct of the submandibular gland. The effects of MTX on unstimulated parotid gland weight, RNA content, and amylase content are consistent with its ability to inhibit protein synthesis through depletion of folate co-factors. However, the mechanism by which the alterations in ion transport occurred is not clear at this time.

The effect of extracellular ATP on intracellular free Ca2+ was characterized in quin2-loaded parotid acinar cells. ATP specifically increased the intracellular Ca2+ concentration six-fold above a basal level of 180 nM. Of other purine nucleotides tested, only adenylylthiodiphosphate (ATP gamma S) had significant activity. ATP and the muscarinic agonist carbachol increased intracellular Ca2+ even in the absence of extracellular Ca2+. Both agonists stimulated K+ release, which was followed by reuptake of K+, even in the continued presence of agonist. In the absence of Mg2+, ATP was much more potent but no more efficacious in elevating intracellular Ca2+, suggesting that ATP4- is the active species. The effect of ATP was reversed by removal with hexokinase, arguing against a role for an active contaminant of ATP and against a non-specific permeabilizing effect of extracellular ATP. Lactate dehydrogenase release was unaffected by a maximally effective concentration of ATP. These observations are consistent with a possible neurotransmitter role for ATP in the rat parotid gland.

A 9-year-old girl had fever, life-threatening interstitial pneumonia, a vesicular skin rash, parotid and submandibular swelling, and marked blood eosinophilia (WBC count 47,000/microL, 39% eosinophils). Results of lung and skin biopsies showed vasculitis with intense eosinophil infiltration. Immunofluorescence analyses of these biopsies, as well as analysis of tissue from the parotid, lip, and trachea, showed striking deposition of eosinophil granule major basic protein associated with areas of tissue damage. Treatment with glucocorticoids and hydroxyurea produced clinical improvement. The association between tissue damage and deposition of the cytotoxic major basic protein suggests that the eosinophil contributed to the pathophysiology of this disease. Recognition of the capacity of the eosinophil to produce tissue damage can be helpful in the selection of therapy.

Studies of the morphology and composition of isolated parotid acinar cells from patients with cystic fibrosis were conducted. It was demonstrated that these cells are larger than cells from controls and have higher concentrations of amylase, Ca, and Na and lower concentrations of K which is suggestive of functional abnormalities in homeostatic and secretory processes.

Highly purified mucin was prepared from monkey (Macaca arctoides) extraparotid saliva by sequential chromatography on Sephadex G-200 (followed by reduction and alkylation of void volume materials), Sepharose CL-2B with 6 M urea, and CM52 cellulose with 6 M urea. Purity was critically ascertained by anion exchange chromatography, ultracentrifugal analysis, isoelectric focusing, sodium dodecyl sulfate-polyacrylamide electrophoresis, and crossed immunoelectrophoresis. Use of crossed immunoelectrophoresis to examine mucin preparations has not been previously reported. This technique was useful for assessing purity and displaying charge and size microheterogeneity in the purified S-carboxymethylated mucin. Threonine and serine comprised 37.8% of the total amino acids while the oligosaccharide moiety contained N-acetyl-glucosamine, N-acetylgalactosamine, fucose, galactose, N-acetylneuraminic acid, and sulfate. Following alkaline borohydride treatment, the carbohydrate chains were found to be linked O-glycosidically between N-acetylgalactosamine and threonine (serine).

This paper deals with the analysis of the nucleolar morphology and distribution of the nucleolar component (i.e. fibrils and granules) in normal and isoproterenol-treated parotid acinar cells of mice. Normally nucleoli present both components intermingled, but at 2 h treatment a considerable decrease of the fibrillar area is detected by a silver staining method. Normal nucleolar characteristics are recovered after eight hours treatment. In hypertrophic cells nucleolar size is considerably increased, but the ratio total nucleolar area/fibrillar area is similar to control cells as shown by a stereometrical computerized analysis. Rounded nucleolar bodies occur in these nuclei which do not seem to be dependent on the modifications induced by the drug.