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This study investigates the effects of essential amino acid (EAA) starvation on murine osteoblasts cells and the underlying mechanisms. We performed and observed the cell proliferation, autophagy, and osteogenic differentiation under deprivation of EAA in vitro. The results showed that EAA starvation resulted in cell cycle arrest via phosphorylation of the MAPK signaling pathway, leading to inhibition of cell proliferation and osteogenic differentiation. Additionally, the LKB1-AMPK signaling pathway was also found to be phosphorylated, inducing autophagy. These findings highlight the significant role of EAA in regulating cellular processes. Furthermore, this study contributes to our understanding of the effects of nutrient deprivation on cellular physiology and may aid in the development of novel therapeutic strategies for diseases associated with amino acid metabolism., Competing Interests: Declaration of competing interest The authors declare no potential conflicts of interest with respect to the authorship and/or publication of this article., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Glycopolypeptide-immobilized particulates exhibit high binding selectivities and affinities for several analytes. However, to date, the conditions for the synthesis of glycopolypeptide-immobilized particulates have not been optimized and the application of these particulates as carriers for affinity chromatography has not been reported. Accordingly, herein, as a model compound for determining the optimal conditions for the immobilization of an artificial glycopolymer on hexyl-containing hybrid silica particulates (HSPs), the glycopolypeptide poly [GlcNAcβ1,4GlcNAc-β-NHCO-(CH 2 ) 5 NH-/CH 3 (CH 2 ) 9 NH-/γ-PGA] (3) containing multivalent chitobiose moieties and multivalent decyl groups with a γ-polyglutamic acid backbone was synthesized. Immobilization of 3 on HSPs under each condition was evaluated by a lectin-binding assay using wheat germ (Triticum vulgaris) agglutinin (WGA), which is an N-acetylglucosamine-binding lectin. As a result, the optimal immobilization conditions for HSPs at 25 mg/mL were obtained at dimethyl sulfoxide (DMSO) concentration of reaction solvent in the range of 1 (DMSO) :9 (water) to 4 (DMSO) :6 (water) and a compound 3 concentration in the range of 125 nM-1250 nM. Furthermore, the influence of the alkyl group structure introduced into glycopolypeptide for imparting hydrophobicity to it on the immobilization of glycopolypeptide on HSPs was investigated. As a result of comparing three types, poly [GlcNAcβ1,4GlcNAc-β-NHCO-(CH 2 ) 5 NH-/γ-PGA] (1) with no alkyl group, poly [GlcNAcβ1,4GlcNAc-β-NHCO-(CH 2 ) 5 NH-/CH 3 (CH 2 ) 4 NH-/γ-PGA] (2) with a pentyl group, and 3 with a decyl group, 3 showed the best immobilization efficiency on HSPs. Finally, 1 mg 3-immobilized HSPs prepared under the optimum conditions adsorbed approximately 7.5 μg WGA in a structure-specific manner. We also achieved a simple WGA purification from raw wheat germ extract as a practical example using 3-immobilized HSPs. We believe that in the future, these glycopolypeptide-immobilized particulates will be used not only for the purification of plant lectins, but also as specific adsorbents for various lectins-like substances such as in vivo lectins, pathogenic viruses, and toxin proteins., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Decidualization - the differentiation of endometrial stromal cells (ESCs) into decidual cells - is a crucial step for successful embryo implantation and placentation that is initiated in the secretory phase of the menstrual cycle. During decidualization, ESCs undergo proliferation arrest and secrete inflammatory mediators, including senescence-associated secretory phenotype (SASP). Although several senolytic agents improve age-related diseases, their effects on cellular senescence in decidualizing ESCs has not been explored. To do this, we treated decidualized ESCs with the senolytic agents Quercetin (Que), Dasatinib (Das), and BPTES. Que decreased the number of senescence-associated β-galactosidase (SA-β-Gal) positive cells and expression of senescence markers in ESCs treated with the decidual stimulus (dibutyryl-cAMP plus progesterone: DP). Concomitantly, Que markedly increased the expression of the decidualization markers IGFBP1, PRL, and FOXO1, in decidualizing ESCs. Similar to Que, Das also stimulated decidualization. Treatment with a combination of Que and Das synergistically increased the expression of decidualization markers and senescence markers compared with treatment with Que or Das alone. However, BPTES did not enhance the expression of decidualization markers. These results imply that treatment with Que and/or Das can remove senescent decidual cells and enhance the decidualization of the rest of ESCs. Thus, senolytic modulation of abnormal ESC decidualization could alleviate infertility caused by dysfunctions of endometrial receptivity and embryo implantation., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The technology to accurately image the morphology of tumor vessels with X-ray contrast agents is important to clarify mechanisms underlying tumor progression and evaluate the efficacy of chemotherapy. However, in clinical practice, iodine-based contrast agents present problems such as short blood retention owing to a high clearance ability and insufficient X-ray absorption capacity when compared with other high atomic number elements. To resolve these issues, gold nanoparticles (AuNPs), with a high atomic number, have attracted a great deal of attention as contrast agents for angiography, and have been employed in small animal models. Herein, we developed novel contrast agents using AuNPs and captured changes in tumor vessel morphology with time using X-ray computed tomography (CT). First, glutathione-supported single nanometer-sized AuNPs (sAu/GSH) (diameter, 2.2 nm) were fabricated using tetrakis(hydroxymethyl)phosphonium chloride as a reducing agent. The sAu/GSH particles were intravenously injected into mice, remained in vessels for a few minutes, and were then excreted by the kidneys after 24 h, similar to the commercial contrast agent iopamidol. Next, the Au/GSH and lactoferrin (sAu/GSH-LF) (long axis size, 17.3 nm) complex was produced by adding lactoferrin to the sAu/GSH solution under the influence of a condensing agent. On intravenously administering sAu/GSH-LF to mice, the blood retention time was 1-3 h, which was considerably longer than that observed with iopamidol and sAu/GSH. Moreover, we succeeded in imaging morphological changes in identical tumor vessels for several days using X-ray CT with sAu/GSH-LF., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The aim of autotransplantation of teeth (ATT) is to replace a lost tooth with a functional tooth within the same patient. Although it has recently become more of a recognized and viable treatment approach in dentistry, the long-term outcomes are still not well-documented. The principal author (M.T.) has performed more than 1000 ATTs for reasons such as treating missing teeth, deep caries, poor endodontic results, and periodontitis over the past 30 years in private practice. During the course of private practice, 2 separate analyses were performed on a total of 319 cases with follow-up ranging from 2-26 years. The results showed a tendency toward higher success rates in younger patients; the success rate was highest in ATTs performed on immature teeth (about 95%), about 90% in patients younger than 30 years of age and approximately 80% in patients older than 30. The failures were most often caused by replacement resorption (ie, ankylosis-related resorption). The purpose of this case series was to show successful long-term outcomes of ATT as well as to provide clinical insights and describe tendencies noted over the course of 30 years of performing ATTs., (Copyright © 2019 John Wiley & Sons A/S and American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: A method that promotes the retrieval of lost long-term memories has not been well established. Histamine in the central nervous system is implicated in learning and memory, and treatment with antihistamines impairs learning and memory. Because histamine H 3 receptor inverse agonists upregulate histamine release, the inverse agonists may enhance learning and memory. However, whether the inverse agonists promote the retrieval of forgotten long-term memory has not yet been determined., Methods: Here, we employed multidisciplinary methods, including mouse behavior, calcium imaging, and chemogenetic manipulation, to examine whether and how the histamine H 3 receptor inverse agonists, thioperamide and betahistine, promote the retrieval of a forgotten long-term object memory in mice. In addition, we conducted a randomized double-blind, placebo-controlled crossover trial in healthy adult participants to investigate whether betahistine treatment promotes memory retrieval in humans., Results: The treatment of H 3 receptor inverse agonists induced the recall of forgotten memories even 1 week and 1 month after training in mice. The memory recovery was mediated by the disinhibition of histamine release in the perirhinal cortex, which activated the histamine H 2 receptor. Histamine depolarized perirhinal cortex neurons, enhanced their spontaneous activity, and facilitated the reactivation of behaviorally activated neuronal ensembles. A human clinical trial revealed that treatment of H 3 receptor inverse agonists is specifically more effective for items that are more difficult to remember and subjects with poorer performance., Conclusions: These results highlight a novel interaction between the central histamine signaling and memory engrams., (Copyright © 2018 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

The ATP-binding cassette subfamily B member 1 (ABCB1) is an efflux transporter that excretes xenobiotics and waste matter. High expression of ABCB1 induced by forskolin (FSK) and rifampicin (RIF) in the bovine blastocysts reportedly improves the cellular quality. In the present study, interferon-α, similar to FSK and RIF, was highly potent in inducing the expression of ABCB1 in the bovine blastocysts but did not exhibit an additive effect with FSK and RIF. Bovine blastocysts stimulated by the combined treatment with FSK, RIF, and interferon-α to express high levels of ABCB1 displayed better freezing resistance as indicated by higher cell numbers in post thawing cultures. On transfer to recipients, such embryos established pregnancies with significantly higher frequencies in repeat breeder cows rather than normal ones., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The mammalian cerebral cortex, which is stratified into six layers, has functional domains that vertically span the six layers, thereby requiring tight interlaminar connectivity within a domain. The synaptic connections in individual layers are first broadly formed under predetermined programs and later reinforced between neurons which reside in the same functional domain via experience-dependent reorganization during the critical period. However, the molecular mechanisms that control these two processes within each layer are still unclear. Therefore, we performed a differential screen for candidates and found seven genes with layer-specific expression during postnatal development of cat visual cortex. APLP1, a transmembrane protein mediating synaptogenesis, started dual-layer expression in layers 2/3 and 5 before the critical period, suggesting that it might execute coarse synapse formation of these layers. STMN2 (SCG10), which promotes microtubule turnover, was unique, as it dramatically shifted its dual-layer distribution from layers 2/3 and 5 to the deeper layers 4 and 6 at the onset of the critical period; it lost this new expression pattern in the adult. Surprisingly, brief dark rearing disturbed the shift in its dual-layer distribution around the onset of the critical period. Thus, by accelerating structural remodeling, STMN2 (SCG10) might launch experience-dependent reorganization of particular layers., (Copyright © 2012 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.)

The Rev-erbα gene is regarded as a circadian clock gene and clock-regulated gene which regulates the circadian transcriptional/translational loop in a subtle way. Here, we first detected the circadian oscillation in mature granulosa cells from antral follicles using a real-time monitoring system of Per2 promoter activity with the addition of FSH. Then we used GSK4112, an agonist ligand of Rev-erbα, to investigate the function of Rev-erbα. GSK4112 treatment significantly reduced the Per2-dLuc amplitude and induced the Per2 oscillation phase advance shift. GSK4112 significantly inhibited Bmal1 mRNA expression, whereas it did clearly stimulate expression of StAR mRNA in a dose-dependent manner. Our data are the first to show the Rev-erbα function in the steroid biosynthesis of rat granulosa cells, and to suggest that Rev-erbα may coordinate circadian rhythm and metabolism in rat ovaries., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Introduction: In a previous report, we showed that 2 types of mineralized tissues were formed in the canal spaces of dogs after tissue engineering treatments of immature teeth with apical periodontitis: (1) dentin- associated mineralized tissue (DAMT) and (2) bony islands (BIs). The objective of this study was to characterize these mineralized tissues., Methods: The maturation and organization of collagen matrices in DAMT, BIs, and the interface between DAMT and the dentin wall were characterized using a histochemical method with picrosirius red staining under polarized light microscopy. In addition, the distribution of 2 noncollagenous proteins (ie, dentin sialoprotein and bone sialoprotein) in these tissues was investigated by immunohistochemical methods with specific antibodies., Results: The results showed that DAMT is distinct from dentin, bone, or BIs. Although it resembled cementum to an extent showing similar immunoreactivity to the noncollagenous proteins, the organization and maturation of collagen matrix was significantly different from cementum. BIs resembled a bone matrix in terms of morphology, collagen organization, and immunoreactivity., Conclusions: The results indicate that DAMT and BIs formed in the canal space are distinct from each other, one exhibiting a unique mineralized tissue and the other a bone-like tissue., (Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Regenerative endodontic treatment on immature teeth with apical periodontitis is promising but still not well-established. The purpose of this study was to explore novel strategies to engineer a vital support structure within a root canal space by a combination of induced blood clot, exposure of dentin matrix, and a cross-linked collagen scaffold., Methods: Apical periodontitis was induced in 6 dogs with immature teeth (n = 64). After disinfection, the following groups were randomly assigned: blood clot (BC) alone, BC with a cross-linked collagen scaffold (CCS), BC with exposure of dentin matrix by ethylenediaminetetraacetic acid (EDTA), and BC with CCS and EDTA. Positive (infected only) and negative controls (untreated) were also included. The dogs were followed up for 3.5 months and killed. Periradicular healing and root wall thickening were radiographically analyzed and statistically evaluated. The jaws were then fixed, demineralized, and subjected to histologic analyses. Newly formed mineralized tissues were histomorphometrically analyzed, quantified, and statistically evaluated., Results: Radiographically there was significant difference in periradicular healing and root wall thickening (P < .05). Histomorphometric analysis showed significantly more mineralized tissue formation in the groups containing the scaffold (P < .05). Exposure of the dentin matrix by EDTA appeared to increase the adherence of the newly formed mineralized tissue to the root walls., Conclusions: The use of cross-linked collagen scaffold and exposure of dentin matrix combined with blood clot might provide an efficient approach to generate a vital support structure for the treatment of immature teeth with apical periodontitis., (Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Oxidative stress is a major pathogenetic factor in hepatic fibrosis. Peroxisome proliferator-activated receptor alpha (PPARalpha) is a nuclear receptor which is known to affect oxidative stress and PPARalpha ligands may have rescue effects on hepatic fibrosis. We tested this hypothesis using rat thioacetamide (TAA) models of liver cirrhosis. Rats were given intraperitoneal injection of TAA and treated with a diet containing one of the two PPARalpha ligands, Wy-14,643 (WY) or fenofibrate. WY treatment dramatically reduced hepatic fibrosis and also prevented the inhibition catalase of mRNA expression caused by TAA. Correspondingly, catalase activity increased in the TAA+WY group but decreased in the control TAA group. The antifibrotic action of fenofibrate in the TAA model was comparable with that of WY. PPARalpha ligands have an antifibrotic action in the rat TAA model of liver cirrhosis, probably due to an antioxidant effect of enhanced catalase expression and activity in the liver.

CCR6 is the receptor of chemokine CCL20. In the present study, we demonstrated that the surface expression of CCR6 was enhanced on the human HCC cell lines (HuH7, PLC/PRF/5, and HepG2) especially on HuH7 cells, but not on HLE or HLF cells. These HCC cell lines (HuH7, PLC/PRF/5, and HepG2) especially the HuH7 cells secreted a significant amount of CCL20 spontaneously, whereas HLE or HLF did not. Stimulation by CCL20 up-regulated the mRNA expression of CCR6 in HuH7 cells and significantly enhanced the growth of HuH7 cells. CCL20-stimulated growth of HuH7 cells was abrogated by the inhibition of downstream signal transduction pathway mediated by p44/42 MAPK, but not by p38 MAPK or SAPK/JNK. CCR6 expression in human HCC tissues was confirmed by RT-PCR. These results indicate that the growth of a proportion of human HCC cells may be mediated by CCL20-CCR6 axis, like HuH7 cells, in an autocrine or paracrine manner.

Heparanase (HPA) degrades heparan sulfate proteoglycan in the extracellular matrix. To understand its role during implantation and placental development in bovine placentae, we cloned and characterized a full-length cDNA encoding bovine HPA and identified HPA localization in placentae. A full-length bovine HPA cDNA was cloned with a 1635 nucleotide open-reading-frame corresponding to a protein of 545 amino acids. The predicted amino acid sequence shares 80.0% and 76.5% identity with human and rat HPA, respectively. In placentomes of 60 and 210 days' gestation, in situ hybridization demonstrated HPA mRNA expression in binucleate cells. Binucleate cells may be a source of HPA throughout gestation in bovine placentae; they may assume specific role(s) in foetal and maternal dialogue. Western blot analysis of bovine placental extracts (day 60) was performed using anti-bovine HPA antibody prepared by immunization of rabbits with synthetic peptide conjugate corresponding to amino acid residues 474-489 of bovine HPA; it showed two immunoreactive proteins with approximate molecular weights of 55kDa and 65kDa. Further, immunofluoresence double staining of HPA and placental lactogen (PL) revealed that binucleate cells expressing HPA had immunoreactivity of PL. These results suggest that HPA is specifically expressed in bovine placental binucleate cells and that it may take migratory roles in placentogenesis for degrading the extracellular matrix.

The development of a multicellular spheroid comprising bovine endometrial epithelial cells (BEE) and bovine endometrial stromal cells (BES) is described in this study. The BES were cultured to confluence in medium with L -ascorbic acid phosphate magnesium salt n -hydrate (AsA-P) which stimulates collagen synthesis in BES. The BEE were co-cultured on a BES cell-sheet for 24h before detachment of the cell-sheet to generate a hetero-spheroid. After EDTA treatment and agitating with pipette, the floating cell-sheet shrank and became an aggregated cell mass in a few days; it finally formed a round-shaped hetero-spheroid composed of BES and BEE. Histological examination found that hetero-spheroids were covered with BEE on the outer layer. When cell viability was examined with TUNEL (terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling), no positive signal was detected in the spheroid for up to 10 days. Immunofluorescence observations showed that spheroids contained abundant extracellular matrices, including type-I, -III, -IV collagen, fibronectin, and laminin. PGF(2alpha) produced by hetero-spheroids in response to oxytocin was significantly higher than those produced by monolayer cultured BEE (P< 0.05). MMPs were not detected in media from spheroids cultured for 5 days after detachment of the cell sheet. These results indicate that bovine endometrial cells have the capacity to regenerate as a multicellular spheroid after treatment with ascorbate in vitro. The spheroid displays an endometrium-mimic feature. Thus, we conclude that spheroids formed by BES and BEE are a useful in vitro model of bovine endometrium.

The present study was conducted to examine effects of hormones and osmolarity on germinal vesicle breakdown (GVBD) and histone H1 kinase (H1K) activity in porcine oocytes cultured in vitro. The basic medium used for culture of oocytes was modified Tyrode's solution in which the osmolarity was adjusted to 134 to 495 mOsm by changing the concentration of sodium chloride (NaCl). When the hormones were present, osmolarity of medium that allows GVBD of oocytes was less than 400 mOsm. However, the range of osmolarity of medium that allows meiotic maturation of oocytes was 210 to 362 mOsm. On the other hand, without hormonal supplement, the incidence of GVBD in oocytes decreased as the osmolarity of the medium increased in the rage of 210 to 362 mOsm. By increasing the osmolarity of the medium from 210 to 362 mOsm by addition with sorbitol instead of NaCl, the incidence decreased from 89.1% to 13.3%. In oocytes cultured in medium of 210 mOsm without hormones, the percentage of oocytes that underwent GVBD and had increased H1K activity 20 h after culture was significantly higher (P < 0.05) than those of oocytes cultured in the same medium supplemented with hormones or medium of 362 mOsm. These results indicate that in vitro induction of GVBD in porcine oocytes is strongly affected by osmolarity of the medium in the absence of hormones. The results also suggest that, under low osmolarity (210 mOsm), GVBD is accelerated with rapid increase of H1K activity.

We have previously reported that intracellular tumor necrosis factor (enTNF) is responsible for resistance, in established cell lines to doxorubicin (DOX), exogenous TNF, and heat stress by inducing manganous superoxide dismutase (MnSOD), thereby scavenging reactive oxygen free radicals. Leukemic cells from 19 patients (6 acute lymphoblastic leukemia, 13 acute myeloid leukemia) were examined for their sensitivity to DOX and TNF in relation to their enTNF expression and MnSOD activity. Sensitivity to DOX and the expression of enTNF or MnSOD activity were inversely correlated. In a case with acquired resistance to chemotherapy which included DOX, enTNF expression and MnSOD activity were increased. Furthermore, in 14 cases treated with a regimen including an anthracycline, 4 cases that failed to respond to chemotherapy showed relatively high amounts of enTNF expression. KG-1 (human acute myelogenous leukemia) cells transfected with a nonsecretory-type TNF expression vector (pTNF delta pro) showed resistance to DOX. A significant increase in MnSOD levels was also noted in the transfectants. TNF antisense cDNA was transfected into isolated leukemic cells from five patients. Sensitivity of the antisense transfectants to DOX was increased, approximately 1.4- to 2.5-fold. These results suggest that enTNF acts as a resistance factor against DOX in leukemia, and that enTNF may be useful as a predictor of DOX sensitivity in leukemia.

The role of 5'-methylthioadenosine (MTA), formed during the process of polyamine biosynthesis, on differentiation of osteoprogenitor cells was assessed by its effects on alkaline phosphatase (ALP) activity, bone nodule formation and osteopontin contents of cultured rat calvaria (RC) cells. These three markers were stimulated by exogenous MTA and were depressed by 5'-difluoromethylthioadenosine (DFMTA), a synthetic inhibitor of MTA phosphorylase, which cleaves MTA to adenine and 5-methylthioribose-1-phosphate. 5-Methylthioribose and 2-keto-4-methylthiobutyrate, metabolites of 5-methylthioribose-1-phosphate, had no effects on ALP activity and bone nodule formation in the presence or absence of DFMTA. On the other hand, adenine enhanced ALP activity, bone nodule formation and osteopontin contents in mineralized nodules and also partially reversed DFMTA-induced inhibition of these three markers. MTA, its metabolites and DFMTA did not affect the growth of RC cells under these culture conditions. These results suggest that adenine formed from MTA is important in the differentiation of RC cells.

The effect of interleukin (IL)-1 on the occurrence of stress-induced gastric erosions was examined in rats. The intracerebroventricular (icv) administration of IL-1 beta significantly inhibited the occurrence of water-immersion restraint stress-induced gastric erosion at doses of 200 ng, 500 ng and 1 microgram, whereas the intravenous (iv) administration of IL-1 beta altered the occurrence of gastric erosion only at a dose of 1 microgram. The inhibitory effect of IL-1 alpha icv administered on the occurrence of gastric erosion was found only at a dose of 1 microgram. The inhibitory effect of IL-1 beta icv administered on the occurrence of stress-induced gastric erosion was not influenced by icv administration of alpha-helical CRF(9-41), a corticotropin-releasing factor (CRF) receptor antagonist. Indomethacin completely blocked the inhibitory action of IL-1 beta icv administered on stress-induced gastric erosion. It is concluded from these results that IL-1 acts mainly in the central nervous system to inhibit the occurrence of stress-induced gastric erosion and that the IL-1 beta-induced inhibition of gastric erosion is mediated by prostaglandin in a manner that is independent of brain CRF.

The effects of chronic central administration of corticotropin-releasing factor (CRF) on food intake, body weight, and hypothalamic-pituitary-adrenocortical hormones were investigated in rats. The infusion of ovine CRF at doses of 0.3 and 1.0 microgram/h continuously induced decrease in food intake and a suppression of body-weight gain for 7 days. The inhibition of body weight gain induced by CRF could not be accounted for solely by a decreased food intake since the suppression of body-weight gain in CRF-infused rats was significantly greater than that observed in rats which received the same amount of food as the CRF-infused rats. The content of proopiomelanocortin (POMC) -derived peptides in the anterior lobe of the pituitary as well as the plasma levels of ACTH and corticosterone (B) were significantly elevated in CRF-treated rats, and the CRF content in the hypothalamus was significantly decreased. These results suggest that chronic intracerebroventricular (icv) administration of CRF stimulates the synthesis and secretion of POMC-related peptides in the pituitary and suppresses food intake accompanied by inhibition of body weight gain. The results are similar to clinical and laboratory findings observed in patients with stress-induced anorexia.

Gastric lesions are known to be caused by stress. Corticotropin-releasing factor (CRF) is a key peptide initiating various stress response. This study was designed to investigate how brain CRF is involved in the occurrence of stress-induced gastric erosion in rats. Intracerebroventricular (icv) administration of CRF suppressed the occurrence of gastric erosion induced by water-immersion restraint stress, and its suppressive effect was blocked by coadministration of a CRF receptor antagonist in rats. The peripheral administration of CRF had no influence on the occurrence of erosion. The icv administration of a CRF receptor antagonist or anti-rat CRF gamma-globulin increased gastric erosion induced by the stress. Ganglionic blockade with chlorisondamine, muscarinic blockade with atropine, or bilateral adrenalectomy by itself significantly inhibited the occurrence of stress-induced gastric erosion, and no additional effect of CRF on these treatments-induced inhibition of erosion was found. These results, therefore, suggest that the occurrence of stress-induced gastric erosion is mediated by the autonomic nervous system- and adrenal-dependent pathway, and that brain CRF reduces the occurrence of stress-induced gastric lesions by acting on its specific receptor within the central nervous system, probably through the autonomic nervous system- and adrenal-dependent mechanism.

The effect of somatostatin on corticotropin-releasing factor (CRF)-induced anorexia was examined in rats. Intracerebroventricular (icv) administration of 0.11 nmol and 0.21 nmol ovine CRF significantly suppressed food intake of 24 h-starved rats. Icv administration of 0.31 nmol somatostatin 14 and somatostatin 28 partially reversed suppression of food intake induced by icv injection of 0.21 nmol CRF in 24 h-starved rats. These results suggest that somatostatin may counteract the suppressive effect of CRF on food intake within the central nervous system.

The effects of Na ion and choline chloride on the release of atrial natriuretic factor (ANF) and growth hormone-releasing factor (GHRF) from rat hypothalamic fragments including the organum vasculosum of the lamina terminalis (OVLT) were examined in vitro. Although the release of ANF was stimulated by Na ion, choline chloride, and glucose in concentration-dependent manners, the release was more sensitive to a change in concentration of Na ion than to those of choline chloride and glucose. On the other hand, the change in Na ion concentration did not affect the release of GHRF. It can be therefore proposed that Na ion is the first candidate controlling ANF release from the brain tissue and that ANF in the hypothalamus and/or OVLT may play some role in the regulation of the Na ion and water balance in the central nervous system.

In vitro release of atrial natriuretic factor (ANF) from rat hypothalamic fragment during 60 min incubation was studied using a specific and sensitive radioimmunoassay (RIA). The Sephadex G-75 gel filtration profiles of the incubation medium revealed that the majority of released ANF-like immunoreactivity (LI) had a molecular weight same as alpha-atrial natriuretic polypeptide and a small amount of ANF-LI of larger molecular size was also released. The release of ANF was increased by addition of 50 mM KCl and the release by 50 mM KCl was completely suppressed in the presence of 2 mM EGTA, a chelating agent of Ca2+. A23187, a Ca2+ ionophore, at a concentration of 2 X 10(-4) M augmented the release of ANF-LI. These results indicate that hypothalamic ANF is released in a Ca2+-dependent manner like other hypothalamic peptides. This suggests that hypothalamic ANF acts as a neurotransmitter and/or neuromodulator in the hypothalamus and possesses some role in the regulation of pituitary hormone secretion.

Compared to either compound alone, the combination of acivicin and cis-diamminedichloroplatinum(II) markedly enhanced the inhibition of the activities of thymidylate synthase and thymidine kinase, the enzymes involved in the final steps of the de novo and salvage pathways in pyrimidine metabolism in A549 lung cancer cells. The enhancement of enzymic inhibition paralleled that of cell growth inhibition. These results indicate that the combination of these drugs can inhibit the capacities of the pyrimidine pathways, resulting in an efficient reduction of DNA synthesis.

Ingestion of glucose is known to induce suppression of GH secretion in normal subjects and this phenomenon is often absent in acromegalic patients. To clarify the mechanism of GH suppression in acute hyperglycemia in normal subjects and disturbed GH response in acromegalic patients, the effects of acute hyperglycemia on plasma GH and TSH levels were examined in normal subjects and acromegalic patients. Plasma GH levels were significantly lowered 45-60 min after ingestion of 75 g glucose and elevated at 210 and 240 min in nine normal subjects. Plasma TSH levels were also significantly lowered between 45 and 120 min after ingestion; levels then gradually rose. Subcutaneous administration of 50 micrograms SMS 201-995, a long acting somatostatin analog, lowered plasma TSH levels in both normal subjects and acromegalic patients, and there was no significant difference in the degree of decrease in plasma TSH levels between the normal subjects and patients. These results, taken together with several reports that somatostatin suppresses TSH secretion as well as GH secretion, suggest that acute hyperglycemia stimulates somatostatin release from the hypothalamus, thus causing inhibition of GH and TSH secretion. However, in ten acromegalic patients, only two showed suppression of plasma GH levels to below 50% of basal level and the degree of suppression of TSH secretion was significantly less than in normal subjects in the glucose tolerance test. It is, therefore, suggested that somatostatin release in response to acute hyperglycemia is impaired in most acromegalic patients and that this abnormality may be one of causes for the absence of the normal GH response to acute hyperglycemia in this disorder.

The mechanism by which restraint stress induces suppression of food intake and the influence of intracerebroventricular (icv) administration of somatostatin on the anorexia induced by restraint stress were examined in the rat. Ninety minutes of restraint stress reduced food intake of rats to approximately 60% that of control. Anorexia induced by 90 min restraint stress was partially reversed by icv administration of alpha-helical CRF (9-41), a corticotropin-releasing factor (CRF) antagonist, and completely reversed by anti-CRF gamma-globulin. These results provide further evidence in support of the theory that CRF is involved in the inhibitory mechanism of food intake in restraint stress. ICV administration of somatostatin 14 and SMS 201-995, an analog of somatostatin, also reversed restraint stress-induced anorexia. It is, therefore, suggested that somatostatin may counteract the suppressive action of CRF on food intake in stress.

Synthetic rat atrial natriuretic factor (ANF) was found to attenuate, in a dose-dependent manner, basal and corticotropin-releasing factor-induced secretion of proopiomelanocortin-derived peptides from cultured anterior and intermediate lobe cells of rat pituitary. ANF was also found to suppress basal and growth hormone-releasing factor-stimulated secretion of growth hormone from anterior lobe cells of rat pituitary. These results, together with reports of the existence of ANF-positive neurons in the hypothalamus and ANF-positive fibers in the median eminence, suggest that hypothalamic ANF is probably involved in the regulation of pituitary hormone secretion, especially that of proopiomelanocortin-derived peptides and growth hormone.