Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biologically active peptides modulate pupillary responsiveness in many non-primate mammals. We examined the action of seven different peptides on iris sphincter and dilator muscles of rhesus monkey. Iris sphincter and dilator muscle preparations from rhesus monkeys were mounted in an organ bath, and tension changes were recorded by an isometric transducer. Electrical field stimulation (100Hz, 0.3 msec, 10V) was applied through a pair of platinum plate electrodes. Monkey iris sphincter and dilator muscles produced simple cholinergic and adrenergic excitatory responses respectively to electrical field stimulation. Strong field stimulation did not elicit slow Substance P (SP) mediated contractions like those in rabbit iris sphincter. Exogenously applied pituitary adenylate cyclase-activating peptide (PACAP) enhanced in a concentration-dependent manner (0.3 nM-0.1 microm) the sphincter response to field stimulation, while neuropeptide Y (NPY) and somatostatin (SRIF) attenuated it. These three peptides did not affect sphincter contractions induced by acetylcholine, and therefore were acting at presynaptically. SP, calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and galanin (GAL) had no effect (at 0.1 microm) on iris sphincter. None of seven exogenously applied peptides had an effect on monkey iris dilator muscle. The innervation of primate irises may be relatively simple compared to non-primates because each of the peptides in this study can modulate miosis or mydriasis in non-primate mammals. Future studies will be expected on the functional significance of species differences in iridial innervation.
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PMID:Action of biologically active peptides on monkey iris sphincter and dilator muscles. 1593 37

Different peptidergic systems have been investigated with some detail during retinal development, including substance P (SP), vasoactive intestinal polypeptide (VIP), pituitary adenylate cyclase activating polypeptide (PACAP) and somatostatin (SRIF). Concerning possible developmental actions of neuropeptides, VIP and PACAP exert protective and growth-promoting actions that may sustain retinal neurons during their development. In addition, the presence of transient SRIF expressing cells and recent observations in SRIF receptor knock out mice indicate variegated roles of this peptide in the development of the retina and of retinofugal projections. Finally, recent studies have shown that, in the developing rabbit retina, changes in the expression pattern of SP receptors are accompanied by modifications of SP physiological effects, indicating that retinal circuits where SP is involved are likely to function in a substantially different manner before the retina becomes involved in the processing of visual stimuli. SP neurotransmission in the immature retina may subserve developmental events, and SP is likely to represent an important developmental factor for the maturation of retinal neurons and circuitries.
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PMID:Neuropeptides and retinal development. 1609 95

The recent development of a specific radioimmunoassay for amphibian (bullfrog, Rana catesbeiana) thyrotropin (TSH) has made it possible to study the effects of various neuropeptides on the release of TSH from the pituitary in vitro. Up to now, corticotropin-releasing factor of bullfrog origin has been shown to have a potent TSH-releasing activity, whereas gonadotropin-releasing hormone and TSH-releasing hormone exhibit a moderate TSH-releasing effect on the adult, but not larval, pituitary. In the present study, the effects of pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal polypeptide (VIP), and somatostatin (SS) on the in vitro release of TSH from the bullfrog pituitary were investigated. Both frog (R. ridibunda) PACAP-38 and PACAP-27 caused a concentration-dependent stimulation of the release of TSH from dispersed pituitary cells during a 24-h culture. The PACAP-38- and PACAP-27-induced TSH release was suppressed by a simultaneous application of PACAP6-38. Application of high concentrations of PACAP6-38 alone caused a slight but significant stimulatory effect on the release of TSH. Frog VIP also stimulated TSH release from pituitary cells concentration-dependently. Frog SS1 (homologous to mammalian somatostatin-14) and SS2 (homologous to mammalian cortistatin) did not affect the basal release of TSH but caused a concentration-dependent suppression of the PACAP-38-induced release of TSH. These results suggest the involvement of multiple neuropeptides in the regulation of the release of TSH from the amphibian pituitary.
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PMID:Effects of pituitary adenylate cyclase-activating polypeptide, vasoactive intestinal polypeptide, and somatostatin on the release of thyrotropin from the bullfrog pituitary. 1688 12

The distribution of neurotensin, neurokinin A, dynorphin A, galanin, somatostatin-28 (1-12), neuropeptide Y, vasoactive intestinal polypeptide, gastrin-releasing peptide, gamma-melanocyte stimulating hormone, alpha-neo-endorphin, angiotensin H, cholecystokinin-8, serotonin and tyrosine hydroxylase has been studied in the pretectal nuclei of the Cyprinus carpio: nuclei pretectalis superficialis parvicellularis and magnocellularis, pretectalis centralis, pretectalis, and pretectalis periventricularis dorsalis and ventralis using an indirect immunoperoxidase technique. We have found neuropeptide Y and serotonin immunoreactive fibres in all pretectal nuclei, whereas gastrin-releasing peptide immunoreactive fibres were visualized in the nuclei pretectalis superficialis parvicellularis and magnocellularis, pretectalis centralis. pretectalis and pretectalis periventricularis dorsalis; neurokinin A immunoreactive fibres in the nuclei pretectalis superficialis parvicellularis and magnocellularis and pretectalis periventricularis dorsalis; galanin immunoreactive fibres in the nuclei pretectalis superficialis parvicellularis, pretectalis centralis and pretectalis periventricularis dorsalis; and neurotensin immunoreactive fibres in the nucleus pretectalis periventricularis dorsalis. Additionally, immunoreactive cell bodies containing neuropeptide Y were observed in the nuclei pretectalis superficialis parvicellularis and pretectalis periventricularis dorsalis, and serotonin and tyrosine hydroxylase cell bodies were found in the nuclei pretectalis periventricularis dorsalis and ventralis respectively. The presence of the neuroactive substances found in the carp pretectal nuclei suggest that they might be involved in the regulation of certain functions within the visual system.
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PMID:Neuropeptides and monoamines in the carp (Cyprinus carpio) pretectum: An immunocytochemical study. 1862 Dec 46

The dissociation chemistry of somatostatin-14 was examined using various tandem mass spectrometry techniques including low-energy beam-type and ion trap collision-induced dissociation (CID) of protonated and deprotonated forms of the peptide, CID of peptide-gold complexes, and electron transfer dissociation (ETD) of cations. Most of the sequence of somatostatin-14 is present within a loop defined by the disulfide linkage between Cys-3 and Cys-14. The generation of readily interpretable sequence-related ions from within the loop requires the cleavage of at least one of the bonds of the disulfide linkage and the cleavage of one polypeptide backbone bond. CID of the protonated forms of somatostatin did not appear to give rise to an appreciable degree of dissociation of the disulfide linkage. Sequential fragmentation via multiple alternative pathways tended to generate very complex spectra. CID of the anions proceeded through CH(2)-S cleavages extensively but relatively few structurally diagnostic ions were generated. The incorporation of Au(I) into the molecule via ion/ion reactions followed by CID gave rise to many structurally relevant dissociation products, particularly for the [M+Au+H](2+) species. The products were generated by a combination of S-S bond cleavage and amide bond cleavage. ETD of the [M+3H](3+) ion generated rich sequence information, as did CID of the electron transfer products that did not fragment directly upon electron transfer. The electron transfer results suggest that both the S-S bond and an N-C(alpha) bond can be cleaved following a single electron transfer reaction.
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PMID:Dissociation of disulfide-intact somatostatin ions: the roles of ion type and dissociation method. 1963 27

Cortistatin (CST) is a newly discovered polypeptide with multiple biological activities that plays a regulatory role in the nervous, endocrine and immune systems. However, the role of CST in the pathogenesis of cardiovascular diseases remains unclear. In this study, we investigated in rats whether CST inhibits vascular calcification induced by vitamin D3 and nicotine treatment in vivo and calcification of cultured rat vascular smooth muscular cells (VSMCs) induced by beta-glycerophosphate in vitro and the underlying mechanism. We measured rat hemodynamic variables, alkaline phosphatase (ALP) activity, calcium deposition and pathological changes in aortic tissues and cultured VSMCs. CST treatment significantly improved hemodynamic values and arterial compliance in rats with vascular calcification, by decreasing systolic blood pressure, pulse pressure, left ventricular end-systolic pressure and left ventricular end-diastolic pressure. CST also significantly decreased ALP activity and calcium deposition, alleviated pathological injury and down-regulated the mRNA expression of type III sodium-dependent phosphate co-transporter-1 (Pit-1) in aortic tissues. It dose-independently inhibited the calcification of VSMCs by decreasing ALP activity and calcium deposition, alleviating pathologic injury and down-regulating Pit-1 mRNA expression. As with CST treatment, ALP activation and calcium deposition were decreased significantly on treatment with ghrelin, the endogenous agonist of growth hormone secretagogue receptor 1a (GHSR1a), but not significantly with somatostatin-14 or proadrenomedullin N-terminal 20 peptide in VSMCs. Further, growth hormone-releasing peptide-6[D-lys], the endogenous antagonist of GHSR1a, markedly reversed the increased ALP activity and calcium deposition in VSMCs. CST could be a new target molecule for the prevention and therapy of vascular calcification, whose effects are mediated by GHSR1a rather than SSTRs or Mrg X2.
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PMID:Cortistatin attenuates vascular calcification in rats. 1976 50


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