Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A porcine brain dipeptidyl-aminopeptidase (DAP) has been purified more than 2400-fold from a crude mitochondrial fraction containing synaptosomes. This enzyme catalyzes the release of free Tyr-Gly from Leu-enkephalin (Km = 2.5 microM) with an optimal activity between pH 6.0 and pH 8.0. The enzyme appears homogeneous as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis devoid of detectable contaminating aminopeptidase activities. The native enzyme is a monomeric protein with a molecular weight of 51,000 +/- 1,000 and an isoelectric point of 4.6 +/- 0.1. This enzyme cosediments with synaptosomes on a Ficoll-sucrose gradient and is partially associated with synaptic plasma membranes. Its activity is inhibited by the metal-chelating agents ethylenediaminetetraacetate and o-phenanthroline. It is not inhibited by the OH-reactive agent phenylmethanesulfonyl fluoride and SH-reactive agents such as p-(chloromercuri)benzoate and N-ethylmaleimide. Among the various biologically active peptides tested, the purified enzyme releases efficiently the N-terminal dipeptide moiety from enkephalins, Trp-Met-Asp-Phe-NH2 (CCK4), and Gly-Trp-Met-Asp-Phe-NH2 (CCK5). At variance, the native peptides CCK8, substance P, neurotensin, and angiotensin II are not cleaved by the DAP. This enzyme is different from other unspecific DAPs, as well as from enkephalin-degrading DAPs previously reported, by its molecular weight and substrate specificity.
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PMID:Purification and characterization of an enkephalin-degrading dipeptidyl-aminopeptidase from porcine brain. 381 77

Effects of some possible neurotransmitters such as GABA, adrenergic drugs, and 5-HT and their antagonists on the motility of Angiostrongylus cantonensis were studied. Paralysis was caused by GABA, avermectin BIa (Av-BIa), piperazine and alpha-adrenergic agonists such as adrenaline, noradrenaline, phenylephrine, clonidine and methoxamine, but not by beta-adrenergic agonists such as isoproterenol. The paralysis by GABA or Av-BIa was antagonized by GABA antagonists such as picrotoxin and/or bicuculline with cholinergic agents such as N-methylcytisine (N-MC) or eserine. The paralysis elicited by alpha-adrenergic agonists was antagonized by alpha-adrenergic antagonists such as phentolamine and dibenamine, but not by beta-adrenergic antagonists such as propranolol. 5-HT affected the motility of A. cantonensis paralytically or spastically. The paralysis induced by 5-HT was antagonized by alpha-adrenergic antagonists such as phentolamine and dibenamine, while the contraction induced by this compound was further stimulated by N-MC, but antagonized by strychnine. Other agents such as glutamine, glycine, aspartic acid, taurine, and substance P showed little effect on the motility of A. Cantonensis. From these findings on the neuropharmacological properties of A. cantonensis, it is suggested that this worm is useful as an excellent nematodal model for the investigation of anthelminthics. In addition, this worm may also useful as one of screening models of drugs affecting the central nervous system in mammals.
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PMID:Studies on chemotherapy of parasitic helminths (VIII). Effects of some possible neurotransmitters on the motility of Angiostrongylus cantonensis. 612 26

A novel mammalian tachykinin, designated "neuromedin L", has been isolated from porcine spinal cord by using bioassay for a tachykinin-like effect on contractility of smooth muscle preparation from guinea pig ileum. By microsequencing, the peptide has been determined to be His-Lys-Thr-Asp-Ser-Phe-Val-Gly-Leu-Met-NH2. This structure has been confirmed by synthesis. Neuromedin L is found to elicit a prompt stimulant activity on guinea pig ileum in a manner similar to that of substance P, and to have remarkable sequence homology to kassinin as well as neuromedin K, which we have recently identified as a mammalian tachykinin. These facts suggest that neuromedin L may participate in neural transmission in the same manner as other members of the mammalian tachykinin family, such as substance P and neuromedin K.
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PMID:Neuromedin L: a novel mammalian tachykinin identified in porcine spinal cord. 614 73

Tonin, an esteroprotease isolated from rat submaxillary gland, is a serine protease with trypsin- and chymotrypsin-like activity. The substrate specificity of tonin shows that it differs from kallikreins and is definitely not a renin-like enzyme or an angiotensin-converting enzyme. Tonin can produce directly the vasoactive peptide angiotensin II, from angiotensin I, angiotensinogen and the synthetic tetradecapeptide substrate of renin by cleavage of a Phe-His bond. It has also been found to cleave some Phe and Arg bonds in various substrates such as beta-lipotropin (beta-LPH), adrenocorticotropin (ACTH), pro-opiomelanocortin (POMC) and substance P. Here we describe the complete amino acid sequence of rat submaxillary gland, tonin. Comparison of the sequence of 219 amino acids with other serine proteases, particularly kallikreins, gamma-subunit of nerve growth factor (NGF) and the recently described gamma-renin, reveals extensive similarities. More interestingly, it also reveals the substitution of an Asp residue always found in the serine protease active site triad (Asp, His, Ser) by a Leu residue. This unusual substitution does not seem to affect the proteolytic activity of the enzyme.
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PMID:Amino acid sequence of rat submaxillary tonin reveals similarities to serine proteases. 632 14

Two novel neuropeptides, neurokinin alpha and beta isolated from porcine spinal cord, were announced. We have synthesized neurokinin alpha as Asp-Met-His-Asp-Phe-Phe-Val-Gly-Leu-Met-NH2, which were 98-99% pure by HPLC. Assays on the isolated guinea pig ilium showed neurokinin alpha to have 81% and neurokinin beta to have 65% of the activity of Substance P. Knowledge of these three related peptides having a common activity opens new considerations of their intrinsic physiological roles in neurotransmission versus pharmacological activities, and reappraisal of the diverse activities of Substance P including that in the inflammatory response of the eye.
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PMID:Synthesis and biological activities of neurokinin alpha and beta. 632 48

A new peptide, designated "neuromedin K" has been discovered and isolated from porcine spinal cord by using bioassays for a tachykinin-like effect on the contractility of smooth muscle preparation from guinea-pig ileum. Porcine neuromedin K has been identified by microsequencing as: Asp-Met-His-Asp-Phe-Phe-Val-Gly-Leu-Met-NH2. The sequence thus determined has been confirmed by synthesis. Neuromedin K has been found to have not only a remarkable sequence homology to kassinin and substance P, but also a prompt stimulant activity on guinea-pig ileum in a manner similar to that of substance P, suggesting that neuromedin K may be involved in neural transmission.
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PMID:Neuromedin K: a novel mammalian tachykinin identified in porcine spinal cord. 657 85

In vitro and in vivo test systems were used to compare the biological activities of substance P and the neurokinins A and B with those of a newly isolated substance P-like acidic peptide, PG-SPI (pGlu-Pro-Asn-Pro-Asp-Glu-Phe-Phe-Gly-Leu-Met-NH2). On nearly all the isolated smooth muscle preparations tested, PG-SPI appeared only slightly more potent than SP, but on guinea pig trachea it was 50 times more potent. The in vitro spasmogenic effect of PG-SPI on guinea pig trachea was inhibited by the NK1 receptor antagonist, CP 96,345. In in vivo tests, intracerebroventricularly injected PG-SPI was about 20 times more potent than SP in inhibiting gastric acid secretion and emptying in rats. Tests with antagonists showed that CP 96,345 reduced PG-SPI-induced inhibition of gastric emptying and the NK2 receptor antagonist, MEN 10,376, sharply blocked PG-SPI-induced inhibition of gastric acid secretion. These findings fit poorly into the current classification of tachykinin receptors and suggest that the acidic substance P-like peptide is a valuable tool for studying the functional role of other tachykinin receptor subtypes.
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PMID:Parallel bioassay of PG-SPI, an amphibian acidic SP-like peptide, mammalian basic substance P, and neurokinins A and B on in vitro and in vivo test systems. 747 92

In order to shed some light on the neurotransmitters in the spinothalamic tract (STT), we examined, biochemically and immunohistochemically, the contents of various neurotransmitter candidates in the terminal field of the STT after cervical hemi-chordotomy (HC) and dorsal quadrant-chordotomy (dQC) in the rat. Substance P (SP), calcitonin gene-related peptide (CGRP), enkephalin, neuropeptide Y, neurotensin, oxytocin and dynorphin A were analyzed immunohistochemically. The contents of neuropeptides (SP, CGRP and cholecystokinin octapeptide) were measured by radioimmunoassay and those of amino acids (aspartic acid, glutamic acid, gamma-aminobutyric acid (GABA) and glycine) and noradrenaline were determined using high-performance liquid chromatography. Cervical hemi-chordotomy, but not dQC, caused significant decreases of the SP-like immunoreactivity in and SP content of the ventral thalamus on the ipsilateral side, compared with that on the contralateral side and of rats subjected to sham-operation. However, neither HC nor dQC resulted in any changes in the ventral thalamic contents of other putative neurotransmitters examined. These results suggest that, in rats, the STT contains SP and that SP-positive fibers run in the ventral half of the ascending spinal tract at the cervical level.
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PMID:Substance P is a possible neurotransmitter in the rat spinothalamic tract. 753 53

It has been postulated that gut peptides play a major role in the regulation of rectal gland secretion in elasmobranchs. An isolated perfused rectal gland secretion in elasmobranchs. An isolated perfused rectal gland preparation was developed for Scyliorhinus canicula that responded to dibutyryl 3',5'-cyclic monophosphate plus 3-isobutyl-1-methylxanthine, increasing chloride clearance rates threefold over basal levels. Activity was stimulated by an endogenous peptide, isolated in pur form by reverse-phase high-performance liquid chromatography from the intestine of S. canicula. The primary structure was established as Ser-Pro-Ser-Asn-Ser-Lys-Cys-Pro-Asp-Gly-Pro-Asp-Cys-Phe-Val-Gly-Leu-Met- NH2. This is a sequence identical to that of the tachykinin scyliorhinin II. Perfusion of synthetic scyliorhinin II increased secretion rate in the rectal gland of S. canicula in a dose-dependent manner with a maximal response at 10(-6) M, whereas vasoactive intestinal peptide, a stimulator in the spiny dogfish, Squalus acanthias, had no effect. We propose that scyliorhinin II is the uncharacterized peptide rectin, previously identified from the intestine of S. canicula.
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PMID:Characterization of the endogenous intestinal peptide that stimulates the rectal gland of Scyliorhinus canicula. 754 63

Pretreatment of isolated mast cells with analogs of neurotensin 8-13 (NT8-13), in which the amino acids Leu13 or Ile12 are replaced with an aspartic acid (Asp13-NT8-13 or Asp12-NT8-13), inhibits the secretion of histamine in response to NT. A 10 min pretreatment with either analog (10 microM) inhibited NT-induced histamine release by 90% (Asp13-NT8-13) or by 98% (Asp12-NT8-13). At concentrations that are inhibitory, Asp13-NT8-13 and Asp12-NT8-13 alone elicit very little release (< 5% at 10 microM). In the continued presence of the analogs, the inhibitory effect lasts for more than 45 min; removal of the analogs resulted in restoration of sensitivity to NT within 10 min. Pretreatment with analog Asp13-NT8-13 resulted in a 39% inhibition of stimulation by substance P and a 52% inhibition of stimulation by histamine-releasing peptide (HRP). In contrast, pretreatment with analog Asp12-NT8-13 gave no inhibition of release by SP or HRP. Neither analog inhibited histamine release in response to bradykinin (BK), NT1-12, compound 48/80 (48/80), the calcium ionophore A23187, or anti-IgE stimulation of passively sensitized mast cells. Although Asp12-NT8-13 and Asp13-NT8-13 differ slightly in regard to the peptides they inhibit, both probably act at a step early in the stimulus-secretion coupling sequence; most likely before the rise in the level of free intracellular calcium that has been shown to accompany secretion in mast cells. It is suggested that these analogs exert their inhibitory effect on NT by competing with NT for a binding site on the mast cell membrane.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Inhibitory effects of the neurotensin8-13 analogs Asp13-NT8-13 and Asp12-NT8-13 on mast cell secretion. 768 73


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