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)

The effects of various neurogenic peptides and neurotransmitter substances on the release of ACTH induced by hypothalamic corticotropin releasing factor (HY-CRF) were investigated using monolayer cultured anterior pituitary cells. Test substances were given in combination with 0.05-0.1 hypothalamic extract (HE)/ml, because HE evoked a significant ACTH release and a linear dose response relationship was demonstrated sequentially between 0.0165 HE/ml and 0.5 HE/ml. Relative high doses of lysine-vasopressin showed a slight additive effect on the release of ACTH induced by 0.1 HE/ml. Leu-enkephalin, dopamine, prostaglandin E1 and E2 slightly reduced the release of ACTH induced by HY-CRF, but the inhibitory effect of these substances were not dose-related. Other tested substances including luteinizing hormone releasing hormone, thyrotropin releasing hormone, somatostatin, melanocyte stimulating hormone release inhibiting factor, beta-endorphin, neurotensin, substance P, vasoactive intestinal polypeptide, angiotensin II, norepinephrine, serotonin, acetylcholine, histamine and gamma-amino butyric acid showed neither agonistic nor antagonistic effect on the release of ACTH induced by HY-CRF. These results indicate that the release of ACTH is controlled specifically by HY-CRF and corticosterone, and modified slightly by some other substances such as vasopressin and prostaglandins, and that the effect of most other neurogenic peptides and neurotransmitter substances is negligible or non-physiological at the pituitary level.
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PMID:ACTH release in pituitary cell cultures. Effect of neurogenic peptides and neurotransmitter substances on ACTH release induced by hypothalamic corticotropin releasing factor (CRF). 3 43

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

Leu-enkephalin (Leu-Enk), norepinephrine (NE), somatostatin (SS), and bradykinin (BK) decrease the voltage-dependent calcium current in NG108-15 cells. Here we have investigated whether distinct G proteins, or a G protein common to all of the pathways, mediates this inhibition. We found that pertussis toxin (PTX) reduced all of these transmitter actions, except that of BK. To examine which of the PTX-sensitive pathways is transduced by GoA, we constructed an NG108-15 cell line that stably expresses a mutant, PTX-resistant alpha subunit of GoA. After treatment with PTX, the mutant GoA alpha rescued the Leu-Enk and NE pathways but not the SS pathway. At least three different G proteins can transduce receptor-mediated inhibition of calcium currents in nerve cells. The effects of these G proteins appear to converge on the omega-conotoxin GVIA-sensitive calcium current.
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PMID:Inhibition of the omega-conotoxin-sensitive calcium current by distinct G proteins. 134 51

Superior cervical ganglia from 7 human cadavers (3-7 h post mortem) were immunostained for tyrosine hydroxylase (TH), dopamine-beta-hydroxylase (DBH) and 14 different neuropeptides. The results show that ganglionic cells contain TH, DBH, neuropeptide Y (NPY), somatostatin, vasoactive intestinal polypeptide (VIP) and calcitonin gene-related peptide (CGRP). These substances were present predominantly within large ganglionic cells. Inside the ganglion, the number and topographical distribution of various types of immunoreactive cells differed from one another. NPY and CGRP immunoreactivities were found in some TH-positive cells, but that co-localization never exceeded the 30% of the TH cells. Leu-enkephalin showed a weak immunoreactivity, which was restricted to fibers or varicosities. Neuropeptides like substance P, dynorphin A and B, cholecystokinin, galanin, corticotropin-releasing factor, thyrotropin-releasing hormone, angiotensin II and neurotensin showed no immunoreactivity in the human superior cervical ganglion.
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PMID:Neuropeptides in the human superior cervical ganglion. 135 73

We have seen that mRNA for several neuropeptides can be visualized at the microscopic level in human post-mortem brain tissues using in situ hybridization histochemistry and oligonucleotides as probes. The specificity of the hybridization signal detected in each case is supported by several criteria such as Northern blot analysis, use of at least two oligonucleotides complementary to different regions of the same target mRNA, cohybridization of labeled and excess unlabeled oligonucleotide probes, and melting curve analysis of the formed hybrids. Furthermore, factors such as age, post-mortem delay or gender did not show a significant effect in the levels of hybridization in the control population studied. Hybridization signals comparable to those found in the control population were obtained in frozen tissues, stored for up to 6 years before analysis. The results obtained for the different neuropeptides examined are, in general, in good agreement with the available information on their distribution and cellular localization as determined by radioimmunoassay or immunohistochemistry. The use of in situ hybridization histochemistry has clearly revealed the location of neurons synthesizing these neuropeptides, adding important information to that provided by radioimmunoassay or immunohistochemistry. A typical example is the identification of peptide synthesizing neuronal cell bodies by immunohistochemistry. This requires, in some cases, the use of treatments such as colchicine, obviously impossible with human brain tissues. The abundance of mRNA could be further related to transcriptional activity and, when compared with peptide levels, can provide some clues on peptide turnover rates. Thus in the hypothalamus, the paraventricular and supraoptic nuclei were found to contain cells expressing arginine-vasopressin and oxytocin mRNAs. Their distribution was in good agreement with that determined by immunohistochemistry (Dierickx and Vandesande, 1977). We have also found that these nuclei contain transcripts for neuropeptide genes such as preproenkephalin A, neuropeptide Y and somatostatin, in agreement with previously reported immunohistochemical data (Agid and Javoy-Agid, 1985; Emson et al., 1986). In the basal ganglia, numerous cells heterogeneously distributed throughout the caudate and putamen nuclei were found to contain preproenkephalin A mRNA.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:In situ hybridization histochemistry in the human hypothalamus. 148 Jul 62

In order to obtain a greater understanding of the role of aminopeptidases in the degradation of peptides and proteins in the nervous system, we have isolated and characterized leucyl aminopeptidase (EC 3.4.11.1) from human cerebral cortex and studied its action on some physiologically important neuropeptides. The enzyme has a low specificity constant for the hydrolysis of Leu-7-amido-4-methylcoumarin (69s-1M-1) but the peptides Tyr-Gly-Gly and Tyr-Gly-Gly-Phe-Leu (Leu5-enkephalin) were much better substrates (specificity constants 8300 and 18050s -1M-1 respectively). Optimum activity for the degradation of Leu-enkephalin was obtained at pH10.5 in the presence of 5mM-Mn++. A sharp drop in specificity constant occurred with increasing chain length in the series Leu-enkephalin, dynorphin 1-8, 1-10 and 1-13, suggesting that the enzyme functions only as an oligopeptidase. Other neuropeptides were poor substrates (cholecystokinin octapeptide, angiotensin-I) or not hydrolysed at all (somatostatin, Arg8-vasopressin).
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PMID:Human brain leucyl aminopeptidase: isolation, characterization and specificity against some neuropeptides. 168 Feb 22

Retrograde fiber tracing and in situ hybridization were used to determine expression of mRNAs for preprotachykinin A (ppTA), calcitonin gene related peptide (CGRP), preproenkephalin A (ENK), neuropeptide tyrosine (NPY) and somatostatin (SOM) as well as tyrosine hydroxylase (TH) in the petrosal ganglia primary sensory neurons which innervate carotid sinus baroreceptors and carotid body chemoreceptors. Perfusion of the carotid sinus with the retrogradely transported dye (Fluoro-Gold) labeled primary sensory neurons in petrosal ganglion. Numerous somata in the petrosal ganglion labeled with dye contained mRNAs for all the above peptides, except SOM. Moreover, TH mRNA was found in a substantial number of retrogradely labeled cells in the petrosal ganglion. This study provides information concerning which of the numerous peptides identified in sensory neurons of petrosal ganglion may be involved in modulation of the arterial baroreceptor and chemoreceptor reflexes.
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PMID:Expression of messenger RNAs for peptides and tyrosine hydroxylase in primary sensory neurons that innervate arterial baroreceptors and chemoreceptors. 168 84

Somatostatin was degraded by the synaptic membrane from rat hippocampus. Cleavage products were separated by reversed phase high performance liquid chromatography and identified by amino acid composition analyses and N-terminal amino acid and sequence determinations around the cleavage sites. Fragments produced from the cleavages at both or either sites between the Phe6-Phe7 and/or between the Thr10-Phe11, together with free phenylalanine and tryptophan, were major cleavage products, followed by that produced from the cleavage of the Asn5-Phe6 bond. The accumulation of the major cleavage products, as well as the initial cleavage of somatostatin, was strongly inhibited by metal chelators and also by specific inhibitors of endopeptidase-24.11 (EC 3.4.24.11), phosphoramidon and thiorphan. The inhibitor susceptibility of the synaptic membrane toward somatostatin was similar to that toward Leu-enkephalin, a natural substrate of endopeptidase-24.11. Furthermore, endopeptidase-24.11 purified from rat brain hydrolyzed somatostatin at the cleavage sites identical to those by the hippocampal synaptic membrane. Thus, it can be concluded that endopeptidase-24.11 plays a major role in the initial stage of somatostatin degradation in rat hippocampus.
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PMID:The degradation of somatostatin by synaptic membrane of rat hippocampus is initiated by endopeptidase-24.11. 197 74

Specific polyclonal antibodies raised against synthetic thyrotropin-releasing hormone (TRH) infused intracerebroventricularly (ICV) significantly decreased gastric lesions induced by cold restraint stress. The antiulcer effect of immunologic blockade of brain TRH was specific. Normal rabbit serum or antibodies raised against somatostatin, alpha-MSH, Leu-enkephalin, gonadotropin-releasing hormone and atrial natriuretic factor were ineffective. These findings suggest that brain TRH may play an important role in experimental stress ulcer formation.
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PMID:Evidence for a role of brain thyrotropin-releasing hormone (TRH) on stress gastric lesion formation in rats. 211 18

The distribution of seven kinds of neuropeptide precursor mRNA-containing neurons was investigated in the rat main and accessory olfactory bulbs, where various peptides have previously been identified immunohistochemically, by means of in situ hybridization using [35S]cRNA probes. In the glomerular layer, numerous preprothyrotropin-releasing hormone mRNA-expressing neurons, moderate numbers of preprosomatostatin and preproenkephalin A neurons, and a small number of preprocholecystokinin neurons were detected. In the external plexiform layer, numerous medium sized preprocholecystokinin and preprocorticotropin-releasing hormone neurons, and a small number of beta-preprotachykinin A neurons were observed. In addition, small preprovasoactive intestinal polypeptide and preprothyrotropin-releasing hormone neurons were evenly distributed in the external plexiform layer. Medium to large sized beta-preprotachykinin A neurons formed a thin layer in the mitral cell layer. In the granule cell layer, in addition to numerous small preproenkephalin A neurons, moderate numbers of small beta-preprotachykinin A and preprocorticotropin-releasing hormone neurons, and a small number of preprothyrotropin-releasing hormone neurons, were identified. Large sized preprosomatostatin neurons were located in the deep layer of the granule cell layer. The distribution patterns of these neurons, as a whole, confirmed previous studies based on immunohistochemistry, although peptide precursor mRNA-expressing neurons were far more numerous than those immunoreactive to the respective neuropeptides. Moreover, mRNA-expressing neurons were observed in areas where no immunoreactive neurons had been observed (e.g. preprovasoactive intestinal polypeptide and preprosomatostatin neurons in the mitral cell layer of the assessory olfactory bulb). The distribution patterns were generally similar in the main and accessory olfactory bulbs.
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PMID:Localization of neuropeptide precursor-synthesizing neurons in the rat olfactory bulb: a hybridization histochemical study. 227 Jan 38


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