Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using HPLC with electrochemical detection, we found that icv somatostatin (Som) 5 or 10 micrograms increased rat's pain threshold and contents of 5-HT and 5-HIAA in hippocampus, hypothalamus and brainstem, except the 5-HIAA content of brainstem in Som 5 micrograms group. However, the changes of NE among above three areas of brain were different, the NE contents of hypothalamus and brainstem significantly increased while that of hippocampus markedly decreased. After icv Som 20 micrograms, hypoxanthine and xanthine in hippocampus and hypothalamus decreased significantly, but encephaledema occurred. Som 40 micrograms icv caused necrotic changes of neurons in brain.
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PMID:[Effect of intraventricular injection of somatostatin on pain threshold, and contents of the monoamines, xanthine, hypoxanthine in rats brain]. 168 90

We investigated the effect of octreotide (OCT), a stable somatostatin analog, (OCT) on changes in short-circuit current (Isc) induced by vasoactive intestinal peptide (VIP), aminophylline, serotonin (5-HT) and substance P. OCT significantly decreased basal Isc at a concentration of 10(-9) M; the maximum decrease in Isc was observed at 10(-6) M. OCT (10(-7) M) significantly inhibited the intestinal secretory response to all the secretagogues studied. The maximum Isc response was reduced when tissues were stimulated with VIP (184.9 +/- 18.0 vs. 119.7 +/- 14.1, P less than 0.05), 5-HT (135.1 +/- 14.4 vs. 79.5 +/- 13.4, P less than 0.05) and substance P (156.0 +/- 19.2 vs. 30.7 +/- 5.4, P less than 0.01). In the case of aminophylline, the concentration-response curve was shifted to the right but the maximum response was not reduced. Because VIP and aminophylline increase cAMP while 5-HT and substance P stimulate intestinal secretion principally by a calcium linked mechanism, we conclude that OCT inhibits Isc in rat colon by more than one mechanism.
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PMID:Octreotide inhibits increases in short-circuit current induced in rat colon by VIP, substance P, serotonin and aminophylline. 169 51

Release of [3H]acetylcholine ([3H]ACh) was examined in a submucous plexus preparation obtained from the guinea pig small intestine in vitro. Constant-current field stimulation evoked ACh output; this output was dependent on the stimulus frequency applied. Maximal release was observed at 10 Hz; this release was blocked by tetrodotoxin (1 x 10(-6) M) or in Ca2(+)-free buffer. Serotonin [5-hydroxytryptamine (5-HT)] stimulated the release of ACh dose dependently, with an ED50 of 5 x 10(-7) M. Substance P was ineffective, while vasoactive intestinal peptide weakly stimulated ACh secretion. Several neuropeptides were tested on their ability to modulate 5-HT-evoked ACh release. Dynorphin A inhibited 5-HT-stimulated ACh release, while Met-enkephalin was without any effect. Both somatostatin and galanin were effective modulators, with an inhibitory effect in the submicromolar range and an excitatory effect at higher concentrations. The response characteristics of the cholinergic neurons of submucosal plexus differ markedly from those of the myenteric plexus. These distinct features form an important framework for future functional studies on submucous plexus neurons.
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PMID:Modulation of submucosal cholinergic neurons by 5-hydroxytryptamine and neuropeptides. 170 72

We previously found a relative sparing of somatostatin and neuropeptide Y neurons 1 week after producing striatal lesions with NMDA receptor agonists. These results are similar to postmortem findings in Huntington's disease (HD), though in this illness there are two- to threefold increases in striatal somatostatin and neuropeptide Y concentrations, which may be due to striatal atrophy. In the present study, we examined the effects of striatal excitotoxin lesions at 6 months and 1 yr, because these lesions exhibit striatal shrinkage and atrophy similar to that occurring in HD striatum. At 6 months and 1 yr, lesions with the NMDA receptor agonist quinolinic acid (QA) resulted in significant increases (up to twofold) in concentrations of somatostatin and neuropeptide Y immunoreactivity, while concentrations of GABA, substance P immunoreactivity, and ChAT activity were significantly reduced. In contrast, somatostatin and neuropeptide Y concentrations did not increase 6 months after kainic acid (KA) or alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid (AMPA) lesions. At both 6 months and 1 yr, QA lesions showed striking sparing of NADPH-diaphorase neurons as compared with both AMPA and KA lesions, neither of which showed preferential sparing of these neurons. Long-term QA lesions also resulted in significant increases in concentrations of both 5-HT and 5-hydroxyindoleacetic acid (HIAA), similar to findings in HD. Chronic QA lesions therefore closely resemble the neurochemical features of HD, because they result in increases in somatostatin and neuropeptide Y and in 5-HT and HIAA. These findings strengthen the possibility that an NMDA receptor-mediated excitotoxic process could play a role in the pathogenesis of HD.
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PMID:Chronic quinolinic acid lesions in rats closely resemble Huntington's disease. 171 Jun 57

The use of a somatostatin analogue (SMS 201-995) has greatly facilitated the treatment of patients with the midgut carcinoid syndrome. Clinical studies have shown that SMS reduces the peripheral levels of tumour-produced serotonin (5-HT) and tachykinins, e.g. neuropeptide K (NPK), basally and after pentagastrin provocation. Some studies have indicated an inhibitory effect of SMS on tumour cell growth as well. In the present study we have investigated the effects of SMS on four different human midgut carcinoid tumours maintained in long term culture. Media levels of 5-HT and NPK-LI in tumour cell cultures decreased rapidly during incubation with SMS (10(-8)-10(-10) M) in all four tumours studied without evidence for tachyphylaxis (up to 6 weeks observation period). SMS treatment (10(-8) M) during 4 days reduced the media concentrations of 5-HT by 56%, while the intracellular contents of 5-HT were decreased by 27% indicating dual inhibitory effects on synthesis and secretion of 5-HT from tumour cells. The DNA contents of cultures were not affected by SMS (10(-8) M or 10(-10) M) treatment for 4 or 14 days. When tumour cell cultures were challenged with isoprenaline (IP) (10(-6) M) no reduction of the IP induced release of 5-HT could be detected after pretreatment of tumour cell cultures with SMS (10(-8) M) for 1 h, 4 h or 4 days. These studies provide evidence for a direct action of the somatostatin analogue on midgut carcinoid tumour cells, reducing both synthesis and secretion of hormones from tumour cells. This effect appears not to be related to inhibition of tumour cell growth. The inhibition of 5-HT secretion from tumour cells by SMS seems to operate via a second messenger system different from the one mediating the beta-adrenoceptor stimulated release of 5-HT.
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PMID:The effect of a somatostatin analogue on the release of hormones from human midgut carcinoid tumour cells. 171 51

The lungs of the red-eared turtle, Pseudemys scripta elegans, have been investigated by light-microscopical immunocytochemistry for serotonin (5-HT) and the neuropeptides calcitonin gene-related peptide (CGRP), enkephalin (ENK), bombesin, somatostatin, calcitonin and cholecystokinin. CGRP- or 5-HT-like immunoreactivity (LI) was demonstrated in neuroepithelial bodies (NEBs) and solitary neuroepithelial endocrine cells lying between the ciliated epithelial cells of the intrapulmonary bronchi, and of the primary, secondary and tertiary trabeculae. Furthermore, ENK-LI NEBs were found between the trabecular ciliated epithelial cells. No reaction was observed with antisera against bombesin, somatostatin, calcitonin, and cholecystokinin. Using consecutive sections, CGRP-LI appears to be colocalized with 5-HT-LI in NEB cells. In addition, it was demonstrated that all the ENK-LI NEBs also contain CGRP-LI, whereas only a part of the CGRP-LI NEBs reveal ENK-LI. To our knowledge this is the first demonstration of CGRP- and/or ENK-LI in pulmonary NEBs of a lower vertebrate.
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PMID:Calcitonin gene-related peptide, enkephalin and serotonin coexist in neuroepithelial bodies of the respiratory tract of the red-eared turtle, Pseudemys scripta elegans. An immunocytochemical study. 185 11

The effects of serotonin (5-HT) on gonadotropin and growth hormone release from perifused goldfish (Carassius auratus, L.) pituitary glands were studied. Serotonin, at micromolar concentrations, caused a dose-related release of gonadotropin and an inhibition of growth hormone release in pituitaries from goldfish at different sexual stages. At lower concentrations 5-HT continued to inhibit growth hormone release, but had no effects on gonadotropin release. The stimulatory effects of 5-HT on gonadotropin release could be blocked by ketanserin and cyproheptadine; however, these two antagonists had no effects on 5-HT inhibition of growth hormone release. Perifusion with melatonin had no effect on the release of gonadotropin or growth hormone release. These results demonstrate that 5-HT has a stimulatory effect on gonadotropin secretion, probably through a 5-HT2 receptor type, and an inhibitory effect on growth hormone through an unidentified receptor type. We hypothesize that the effects on gonadotropin release are due to direct actions on gonadotrophs, whereas the effects on growth hormone release may be due to stimulation of somatostatin release from neurosecretory terminals in the pituitary.
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PMID:Effects of serotonin on gonadotropin and growth hormone release from in vitro perifused goldfish pituitary fragments. 187 80

Serotonin-producing pancreatic endocrine tumours are rare neoplasms which in most cases exhibit malignant biological behaviour. These tumours, in the majority of the well-documented cases, are composed of argyrophil- and argentaffin-positive cells which contain large pleomorphic neurosecretory granules. In contrast, argyrophilic non-argentaffin pancreatic endocrine tumours with tumour cells containing round neurosecretory granules are exceptional. In this study we describe such a tumour not associated with clinical evidence of carcinoid syndrome in a 60-year-old woman. Histological examination revealed tumour extension in pancreatic lymphatic vessels and veins but no evidence of locoregional or distant metastases. Ten months after surgery the patient showed no recurrence of the disease. Immunohistochemistry revealed cytoplasmic serotonin production in the tumour cells which were negative for anti-gastrin, insulin, glucagon, somatostatin, pancreatic polypeptide (PP), vasoactive intestinal peptide (VIP) and ACTH. This study emphasizes the usefulness of combined ultrastructural and immunohistochemical investigations in order to identify and characterize the rare pancreatic endocrine tumours with serotonin production.
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PMID:Serotonin-producing pancreatic endocrine tumour. Histological, ultrastructural and immunohistochemical study of a case. 196 80

The effects of lesion of the hypothalamic paraventricular nuclei (PVNx), the main thyrotrophic area, on the cold-stimulated thyrotropin (TSH) responses to intracerebroventricular (i.c.v.) 5-HT were studied in male rats. PVNx significantly attentuated the cold-stimulated TSH levels, but significantly affected neither hypothalamic thyrotropin-releasing hormone nor somatostatin content. Serum T3 levels were significantly decreased 8 days after PVNx. Irrespective of the lesion (sham or PVNx), 5-HT infusion (9 micrograms per rat) into the posterior third ventricle attenuated markedly the cold-stimulated TSH levels, whereas infusion into the anterior third ventricle did not. Bilateral 5-HT infusions (2 micrograms per side) into the hypothalamic dorsomedial nuclei significantly decreased serum TSH, but bilateral infusions into the posterior hypothalamic nuclei were without effect. Sham-lesion and PVNx decreased serum prolactin levels without affecting the stimulation of prolactin secretion by i.c.v. 5-HT. These results suggest that the inhibitory effect of i.c.v. 5-HT on TSH secretion and its stimulatory action on prolactin secretion are only partially dependent on the PVN.
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PMID:Effects of hypothalamic paraventricular nucleus lesion on the cold-stimulated TSH responses to 5-HT in male rats. 197 6

Dissociated cell culture preparations were employed to study intracardiac neurones of the atria from human fetal hearts at 9 to 21 weeks' gestation. Intracardiac neurones were not observed in cultures dissociated from the ventricles. Single neurones, as well as groups, could be identified by phase-contrast microscopy in all of the atrial cultures prepared from 14 to 21 weeks' gestation, and protein gene product 9.5-like immunoreactive neurones were detected in cultures from as early as 10 weeks' gestation. The neurones were mononucleate, with a prominent nucleolus or multiple nucleoli, and often had extensive neurites. Neurones tended to be bigger in cultures from later stages in gestation, and these cells appeared to be more mature with a complex pattern of neurite outgrowth. Many neurones from 15 to 20 weeks' gestation expressed somatostatin-like immunoreactivity in culture. A very low proportion of cultured neurones was immunoreactive for neuropeptide Y and its C-terminal flanking peptide. Neuropeptide Y-like immunoreactive neurones also contained 5-hydroxy-tryptamine-like immunoreactivity in culture, but dopamine beta-hydroxylase-like immunoreactive neurones were not detected. This study is the first description of human intracardiac neurones in culture and forms the essential baseline for further direct investigation of these cells.
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PMID:The intracardiac neurones of the fetal human heart in culture. 197 9


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