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

1 Somatostatin (SS) was evaluated as a chronotropic and inotropic agent in isolated spontaneously beating auricles of rats, rabbits and guinea-pigs.2 SS was completely inactive in rat and rabbit auricles but exerted a dose-dependent, negative inotropic effect in guinea-pig auricles in concentrations between 1.5 x 10(-8) to 1.2 x 10(-6) M.3 The negative inotropic effect of SS (6.0 x 10(-8) and 3.0 x 10(-7) M) was not inhibited by a mixture of antagonists containing practolol (7.9 x 10(-6) M), phentolamine (3.5 x 10(-7) M), methysergide (2.8 x 10(-7) M), diphenhydramine (3.9 x 10(-5) M), cimetidine (4.0 x 10(-5) M) atropine (3.4 x 10(-7) M) and indomethacin (1.4 x 10(-5) M).4 The negative inotropic effect of SS was greatly potentiated by reduction in the Ca(2+) concentration of the medium from 5.0 to 1.25 mM.5 On a molar basis, SS was equipotent with acetylcholine (ACh) as a negative inotropic agent in the guinea-pig auricles.6 SS (6.0 x 10(-8) and 6.0 x 10(-7) M) was found to inhibit selectively the positive inotropic action of neurotensin (NT) in guinea-pig but not in rat auricles.7 The inhibitory action of SS against NT was independent of its negative inotropic action.8 These results suggest that SS produces its negative inotropic action by interacting with specific receptors presumably located in the cell membrane of guinea-pig atria. The interaction between SS and its receptor may cause a decreased Ca(2+) diffusion and/or transport into the atrial cells. The physiological and pharmacological significance of these results is discussed.
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PMID:An analysis of the negative inotropic action of somatostatin. 46 78

Sections of gastric mucosa removed during surgery for cancer or peptic ulcer and containing regions of intestinal metaplasia were studied by the immunofluorescence technique using several antiserums against intestinal hormones. Endocrine cells such as cells containing somatostatin, glicentin (gut GLI-I), motilin, and probably cholecystokinin were found within metaplastic intestinal epithelium while secretin and neurotensin, which are present in the normal intestinal mucosa, were not detected in metaplastic epithelium. The endocrine-cell population present in the intestinal metaplasia resembles that found in the cryptal region of the normal small intestine, a finding in accordance with the fact that intestinal metaplasia of gastric mucosa usually reproduces structural and histochemical characteristics of small intestinal crypts.
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PMID:Endocrine cells in the intestinal metaplasia of gastric mucosa. 47 6

At least four types of endocrine-like cells have been detected histochemically in the mucosa of the human colon and rectum, i.e. argentaffin cells storing 5-hydroxytryptamine (5HT) and non-argentaffin cells reacting with glucagon, somatostatin and bovine pancreatic peptide (BPP) antibodies. Ultrastructurally, four main types and three rare types of endocrine-like cells have been identified. Among the former cells were: (1) argentaffin EC1 cells, known to store 5HT and substance P, (2) poorly argyrophil L cells, corresponding to the glucagon-immunoreactive cells storing enteroglucagon or glucagon-like immunoreactivity (GLl), (3) inconstantly argyrophil F-like cells, possibly corresponding to BPP-immunoreactive cells, and (4) fairly argyrophil H cells of unknown function. Rare D cells, corresponding to somatostatin cells, N cells, corresponding to neurotensin cells, and P cells, of unknown function, have been also found.
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PMID:Types of endocrine cells in the human colon and rectum. 69 14

The reaction products of plasma enzyme degradation of TRH were identified by thin layer chromatography. The enzyme in normal rat plasma yields proline and pGlu-His as major reaction products. High concentrations of proline decrease peptide cleavage, resulting in greater amounts of acid TRH. The apparent Km of the enzyme is 4.1 X 10(-6) M. LHRH and neurotensin are competitive inhibitors with Ki of 5 X 10(-6) M and 1.5 X 10(-5) M, respectively. Somatostatin, MIF, oxytocin, arg-vasopressin, arg-vasotocin, neurophysin II and glucagon do not compete; and pGlu-His-Pro-OH, Glu-His-Pro-OH, pGlu-His, His-Pro-NH2, and Pro-NH2 do not affect enzyme activity. These data suggest that the substrated requires pGlu and a terminal or internal amide to complex with the enzyme. The enzyme is markedly inhibited by Cu++, Bal, benzamadine, p-(chloromercuri)-benzoic acid, moderately affected by EDTA and puromycin, and unaffected by mercaptoethanol. TSH does not affect enzyme activity while LH inhibits it moderately at high concentrations (300-600 pg/ml).
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PMID:Characteristics of the plasma TRH-degrading enzyme. 81 19

Administration of neurotensin to dogs resulted in rises in circulating blood glucose, glucagon and insulin levels, the rise in glucagon being more pronounced than that in insulin. Infusion of somatostatin along with neurotensin suppressed glucagon and insulin responses to neurotensin and prevented the rise in blood glucose levels. These results suggest that the hyperglycemia seen after neurotensin is due to neurotensin stimulation of glucagon release over insulin release.
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PMID:Effect of somatostatin on neurotensin-induced glucagon release and hyperglycemia. 84 24

Although effects of physical environmental stress, including noise and whole-body vibration, on human psychological activities and emotion are not negligible for environmental and occupational hygiene, attempts to elucidate their physiological and biomedical mechanisms have been not made until recently. Neurobiological researches on the effects of the physical environment, e.g., noise and whole-body vibration on organisms were reviewed. It has been well accepted that such effects can be classified into specific and nonspecific reactions to the stressor. Activations of the mesofrontal and the meso-accumbens dopaminergic (DA) systems and changes of frontal substance P (SP) have been reported to play a part in emotional changes and to be induced by acute physical environmental stressors as a nonspecific reaction. On the basis of data demonstrating that these three systems do not show the same changes with the chronic exposure, it is assumed that emotional changes may account for the differences among the systems. Specific responses of amygdaline DA and SP to noise suggest that the psychopharmacological mechanisms by which actions of DA and SP in the cortical association areas for the sensory systems of hearing, as well as in the amygdala and the mesencephalon together, cause the specific sensation of noise, and furthermore lead to psychological and physical nonspecific reactions. In these mechanisms, descending amygdalofugal neural systems of SP, neurotensin (NT) and somatostatin are activated as a common pathway, and subsequently relayed to the hypothalamus-pituitary system responsible for several endocrinological hormones. The involvements of the hippocampal VIP in whole-body vibration and of the DA and NT in cold exposure have been pointed out. Further researches to elucidate the roles of central neurotransmitters in physical environmental stress will be important in the study of human high-level mental activity.
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PMID:[Neurobiology of physical environmental stress]. 128 11

The differential vulnerability of basal forebrain cells to ibotenate (IBO) or quisqualate (QUIS) was investigated in rats. IBO was also coinjected with cystine (CYS) or zinc (Zn). Cortical choline acetyltransferase (ChAT) and glutamate decarboxylase (GAD) activity, neurotensin receptors, and high-affinity choline uptake sites were quantified in conjunction with radioimmunoassays for neurotensin, substance P, and somatostatin; immunocytochemistry for neurotensin-, somatostatin-, Leu-enkephalin-, and ChAT-positive cells; and in situ hybridization histochemistry of somatostatin, substance P, and enkephalin mRNAs. Compared with the performance of controls, continuous alternation performance in a T maze of IBO+Zn or IBO+CYS rats was better than that of IBO rats, whereas the performance of QUIS rats was unimpaired. Of those neurotransmitter systems examined, only ChAT-immunoreactive cells were vulnerable to IBO or QUIS. However, cholinergic cell loss did not correlate with impaired performance.
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PMID:Basal forebrain neurons and memory: a biochemical, histological, and behavioral study of differential vulnerability to ibotenate and quisqualate. 128 13

The possible influence of several neuropeptides on muscarinic receptor binding and function in fronto-parietal cortex of young and senescent Fischer 344 rats was examined. Low concentrations (100 nM) of cholecystokinin, neurotensin and vasoactive intestinal polypeptide (VIP), added in vitro, enhanced carbachol-stimulated phosphoinositide metabolism in cortical miniprisms from both young and senescent rats, while somatostatin was ineffective. Interestingly, the VIP receptor antagonist [d-parachloro-Phe6,Leu17[VIP shifted the dose-response curve for carbachol significantly to the right, indicating inhibition of phosphoinositide hydrolysis. No direct actions of neuropeptides on the number or affinity of [3H]l-quinuclidinyl benzilate binding sites nor on agonist conformation states of the muscarinic receptor were noted in cortex from young animals. The neuropeptide modulation of phosphoinositide metabolism was selective for muscarinic systems, as norepinephrine-stimulated phosphoinositide hydrolysis was not altered. Pretreatment with hemicholinium-3, an inhibitor of high-affinity choline uptake, did not prevent the neuropeptide effects, indicating the interaction was probably postsynaptic. It is possible that pharmacologic manipulation of peptidergic processes could improve cholinergic neurotransmission in brain.
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PMID:Neuropeptide modulation of muscarinic receptors and function in cerebral cortex of young and senescent rats. 131 40

Preparation of isolated large intestine of the frog was filled with Ringer's solution diluted with distilled water (1:5) and was placed into the glass with normal Ringer's solution. The preparation was weighed within every 30 min and the osmotic permeability was determined for water of the mucous and serous layers of the intestine. Then one of the peptides was added to Ringer's solution and the experiment continued. It is stated that bombesin, neurotensin, encephalins, substance P, somatostatin, pituitrin are able to change liquid absorption from the large intestine cavity when the concentration of Ringer's solution in the cavity and from its serous surface is the same. Bombesin and neurotensin inhibited while encephalins stimulated liquid absorption and these effects depended on the transport of ions. Liquid absorption by the osmotic gradient decreased using bombesin, substance P and increased using somatostatin. More complex peptide-peptide relations are observed if using pituitrin and other peptides. cAMP is shown to participate in bombesin effects.
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PMID:[The effect of regulatory peptides on water absorption in the large intestine of the frog]. 131 80

A patient with metastatic VIP-producing pancreatic tumor was successfully treated with subcutaneous octreotide, an analogue of somatostatin, for more than 4 years. The profuse diarrhea was rapidly controlled and the plasma concentrations of the hormones (VIP, neurotensin, gastrin, pancreatic polypeptide) fell to nearly normal within 2 months. Because of asymptomatic increase in tumor size, we added chemotherapy 2 years later. Since the drug is rapidly effective and well tolerated, it will probably become the therapy of choice in this syndrome.
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PMID:[Long-term therapy of a metastasizing pancreatic vipoma using the somatostatin derivative octreotide]. 132 86


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