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)

1. We have investigated the ability of prostacyclin (PGI2) to contract guinea-pig isolated bronchi and the possible involvement of capsaicin-sensitive primary afferents in the response to PGI2. 2. PGI2 (0.1-100 microM) produced concentration-dependent contractions of the guinea-pig isolated bronchi. In vitro capsaicin desensitization (10 microM for 30 min followed by washing) significantly reduced the PGI2-induced contraction at all concentrations tested. A capsaicin-resistant component of contraction (40-60% of the overall response) was also evident. 3. Ruthenium red (3 microM), an inorganic dye which acts as a selective functional antagonist of capsaicin, significantly decreased PGI2-induced contractions, without affecting the response to substance P, neurokinin A or acetylcholine. 4. MEN 10, 207, (Tyr5, D-Trp6,8,9, Arg10)-neurokinin A (4-10) (3 microM), a selective antagonist of NK2-tachykinin receptors, significantly decreased PGI2-induced contractions and neurokinin A-induced contractions, without affecting the response to acetylcholine. 5. The effect of ruthenium red and MEN 10,207 on the one hand, and that of ruthenium red and capsaicin on the other was non additive. 6. These results indicate that PGI2-induced contraction of the guinea-pig isolated bronchi involves two distinct mechanisms, one of which involves transmitter (tachykinins) release from peripheral endings of capsaicin-sensitive primary afferents. In as much as PGI2-activation of primary afferents is sensitive to ruthenium red, we suggest that PGI2 shares a common mechanism of tachykinin release with that activated by capsaicin.
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PMID:Prostacyclin activates tachykinin release from capsaicin-sensitive afferents in guinea-pig bronchi through a ruthenium red-sensitive pathway. 172 16

The NK3 agonist, senktide, induced a potent contraction of rat uterus in the presence of tetrodotoxin, atropine and indomethacin, or the tachykinin receptor antagonists L-659877 and [D-Pro4,D-Trp7,9,10]substance P (4-11). Additional contractile and radioligand binding studies with receptor selective agonists and antagonists confirmed the presence of NK3 receptors and also revealed the presence of NK1 and NK2 receptors. The rat uterus is the second peripheral tissue in which a post-synaptic, non-neuronal NK3 receptor has been identified.
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PMID:The presence of NK3 tachykinin receptors on rat uterus. 172 57

Recent in vitro studies have shown that the dose-response curve of substance P on [3H]protein secretion from rat parotid glands is biphasic. Such a response could result either from the activation of tachykinin receptors or from the amphiphilic character of substance P, since it has previously been shown that the N-terminal part of substance P may play an important role in the activation of phosphoinositides in rat parotid glands. To investigate these possibilities, we studied the effects of selective NK1, NK2, NK3 receptor agonists and C-terminal fragments of substance P and neurokinin A on protein secretion from rat parotid lobules. The poor activity of NK2 (neurokinin A-(4-10) and [beta-Ala8]neurokinin A-(4-10)) as well as of NK3 ([MePhe7]neurokinin B) selective agonists allowed us to rule out a possible involvement of NK2 and NK3 receptors in the parotid gland secretory process. Conversely, the selective NK1 receptor agonist, [Sar9,Met(O2)11]substance P, reproduced the biphasic dose-response curve for [3H]protein secretion typical of native substance P. However, a biphasic response was not observed with peptides deprived of the N-terminal moiety of substance P, such as substance P-(4-11) or [AcArg6,Sar9,Met(O2)11] substance P-(6-11). Our data therefore indicate that the [3H]protein secretion obtained with substance P results from the activation of NK1 receptors. Moreover, our data suggest that the N-terminal tripeptide of substance P is also active, and could stimulate different phospholipases either by acting through a second functional site on the NK1 receptor or by directly activating G-proteins.
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PMID:Involvement of NK1 receptors and importance of the N-terminal sequence of substance P in the stimulation of protein secretion in rat parotid glands. 172 89

Membranes isolated from a murine fibroblast B82 cell line (SKLKB82#3) transfected with the bovine stomach cDNA pSKR56S exhibited binding of [His(125I)1]neurokinin A (125I-NKA) to a single population of sites with a Bmax of 147 fmol/mg of protein and a Kd of 0.59 nM. Control cell lines had little or no specific binding. The ligand binding in SKLKB82#3 cells was reversible and was inhibited by peptides in the potency rank of neuropeptide gamma greater than neuropeptide K greater than neurokinin A greater than [10-norleucine]neurokinin A-(4-10) greater than substance P much greater than senktide (succinyl-Asp-Phe-MePhe-Gly-Leu-Met-NH2). Specific binding was enhanced by Mn2+, Mg2+, and Ca2+ and was inhibited by guanine nucleotide analogues. Thus, SKLKB82#3 cells have been transfected with NK2 receptors that have become associated with an endogenous guanine nucleotide-binding protein. In comparison with membranes from the hamster urinary bladder, a tissue enriched in NK2 receptors, NK2 receptor antagonists displayed markedly different potencies, either more or less potent, in inhibiting specific binding in membranes of the transfected cells. Furthermore, inhibition of 125I-NKA binding by nucleotide analogues was markedly different in SKLKB82#3 cells compared with hamster bladder tissue. The different binding profile in the cells is not due to an artefact introduced during cDNA transfection because a similar profile was also observed in bovine stomach membranes. These results may indicate the existence of two distinct NK2 receptors.
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PMID:Characterization of a tachykinin peptide NK2 receptor transfected into murine fibroblast B82 cells. 184 6

1. We have compared the ability of various tachykinins and selective tachykinin receptor agonists to induce contraction of the endothelium-denuded rabbit pulmonary artery (RPA) and hamster trachea (HT) and have estimated the affinity of some newly developed NK2 selective antagonists in the same tissues. 2. In confirmation of previous findings, experiments with the agonists indicated that NK2 receptors are the main if not the sole mediators of the response to tachykinins in both RPA and HT. No evidence for significant degradation of neurokinin A (NKA) was found in either tissue when experiments were repeated in the presence of a mixture of peptidase inhibitors (thiorphan, captopril and bestatin, 1 microM each). 3. The peptide antagonists tested were: Peptide I = [Tyr5, D-Trp6,8,9, Arg10]-NKA(4-10); Peptide II = [Tyr5, D-Trp6,8,9, Arg10]-NKA(3-10); Peptide III = Ac-Leu-Asp-Gln-Trp-Phe-Gly-NH2. The three peptides produced a concentration-dependent rightward shift of the concentration-response curve to NKA in both RPA and HT with no significant depression of the maximal response attainable. The slopes of the Schild plots were not significantly different from unity, indicating a competitive antagonism. Peptides I and II were about 100 times more potent in the RPA than in the HT, while Peptide III was about 100 times more potent in the HT than RPA. 4. The pA2 values obtained in these two tissues with the three antagonists were not significantly different when tested in the absence or presence of peptidase inhibitors, or when a selective NK2 receptor agonist, [beta Ala8]-NKA(4-10) was used instead of NKA. Similar pA2 values were obtained after 15 or 90min of incubation with the antagonists. Peptides I, II and III had no inhibitory effect on contractions produced by noradrenaline in the RPA or by carbachol in the HT. 5. Peptides I, II and III showed weak or no antagonistic activity toward the vasodilatator effect of substance P in the dog carotid artery (NK, receptor-mediated) or toward the contractile effect of neurokinin B in the rat portal vein (NK3 receptor-mediated). 6. These results provide pharmacological evidence for heterogeneity of NK2 receptors in the RPA and HT. The NK2 receptors present in these tissues are not discriminated by natural tachykinins or selective agonists, but are recognized with very different affinity by NK2 receptor antagonists.
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PMID:Competitive antagonists discriminate between NK2 tachykinin receptor subtypes. 216 37

The neurokinin A analogue, MDL 28,564 (Asp-Ser-Phe-Val-Gly-Leu-CH2NH-Leu-NH2), inhibited 125I-NKA binding to hamster urinary bladder NK2 receptors with a KI of 130 nM. For rat submaxillary gland NK1 receptors and cerebral cortical NK3 receptors, the KI's for MDL 28,564 were greater than 250 microM and greater than 500 microM, respectively. MDL 28,564 did not relax dog carotid artery (NK1 tissue) or contract rat portal vein (NK3 tissue). In guinea-pig trachea tissues, MDL 28,564 stimulated phosphatidylinositol turnover and induced contraction with maximum effects similar to those of neurokinin A. In hamster urinary bladder tissue, MDL 28,564 stimulated phosphatidylinositol turnover with maximum effect only 10% of that of neurokinin A, did not produce sustained contraction itself and antagonized NKA-induced contraction. MDL 28,564 also produced full contraction in rabbit pulmonary artery (NK2 tissue) but was inactive in rat vas deferens (NK2 tissue). These data with MDL 28,564 are consistent with the NK2 receptors in guinea-pig trachea and rabbit pulmonary artery being different from those in hamster urinary bladder and rat vas deferens.
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PMID:[Leu9 psi(CH2NH)Leu10]-neurokinin A (4-10) (MDL 28,564) distinguishes tissue tachykinin peptide NK2 receptors. 217 Jul 88

Substance K (SK) contracted the guinea pig gallbladder in vitro by predominantly acting on the neurokinin (NK2) receptors localized on the smooth muscle. A comparison of the 50% effective dose among the tachykinins showed that SK is 20 and 176 times more active than neurokinin B (NKB) and substance P (SP), respectively. Senktide, a synthetic NKB agonist with presumably a specificity for only NK3 receptor subtype, was completely inactive even when tested at 6 x 10(-6) M. Studies on both atropine-treated tissues and [3H]acetylcholine release from myenteric plexus have revealed a minor action of SK by way of a stimulation on the intramural cholinergic neurons. There was still a residual 77.4% SK-evoked contraction that was not blocked by atropine. However, the SK-induced contraction was completely abolished in the presence of 1-(5-isoquinolinylsulfonyl)-2-methyl-piperazine, a direct protein kinase C (PKC) inhibitor. This latter observation suggests a link in the PKC-specific pathway of intracellular signal transduction initiated by NK2 receptor activation on the gallbladder musculature. The preponderance of NK2 receptor subtype further implies a unique functional role it may play in gallbladder contractility.
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PMID:Mode of stimulation of gallbladder contraction by substance K. 217 17

To test the effects on gastric acid secretion and gastric emptying of non-mammalian (eledoisin, physalaemin, kassinin), mammalian (substance P. neurokinin A, neurokinin B) and synthetic tachykinins (septide, senktide), intracerebroventricular injections of these peptides were given to conscious pylorus-ligated rats (gastric secretory study) or to animals fed with a phenol red meal (gastric emptying study). The tachykinins able to cause central inhibition of acid output were those active on NK2 and NK3 receptors (eledoisin, kassinin, neurokinin A, neurokinin B and senktide). Tachykinins active on NK1 receptors (substance P. physalaemin and septide) were devoid of this activity. The most potent inhibitor was the synthetic NK3 agonist, senktide. All tested natural tachykinins significantly inhibited gastric emptying, the most potent being those active on NK2 receptors. Septide, the synthetic NK1 agonist, had lowest effect and senktide, the synthetic NK3 agonist, was far less active than eledoisin, kassinin and neurokinin A. Thus, specific tachykinin receptors exist in the rat brain that mediate gastric functions: NK3 receptors participate in the control of gastric secretion, while NK2 receptors seem to be involved in the regulation of gastric emptying by activating inhibitory pathways.
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PMID:Tachykinins: effects on gastric secretion and emptying in rats. 217 57

We have studied the contractile response and phosphoinositide hydrolysis induced by substance P (SP), neurokinin A (NKA), neurokinin B (NKB), and Alp-Phe-Phe(R)-Gly[ANC-2]-Leu-Met-NH2 (L 363851), a selective NK2-receptor agonist, in guinea pig tracheal smooth muscle. The four tachykinins elicited a concentration-dependent contraction in tracheal smooth muscle devoid of epithelium, with the following order of potency: NKA greater than L 363851 greater than NKB greater than SP, (EC50 1.0 x 10(-9) M, 3.2 x 10(-9) M, 7.5 x 10(-9) M and 1.2 x 10(-7) M, respectively), which suggests that NK2 receptors predominate in airway smooth muscle. In the presence of epithelium, the sensitivity of airway smooth muscle to tachykinins was decreased, and the concentration response curves to tachykinins were shifted rightward by 30-fold for SP, 9-fold for NKA, and 5-fold for NKB. The concentration response curve to L 363851 was not significantly shifted in the presence of epithelium. This suggests that epithelium may release a relaxant factor in response to tachykinins via an NK1 receptor. In airway smooth muscle, we found that tachykinins elicited phosphoinositide breakdown with an order of potency similar to that for contractile response (EC50 2.2 x 10(-5) M, 3.6 x 10(-5) M, 4.4 x 10(-5) M, and 5.9 x 10(-5) M). In epithelium, SP alone elicited a significant phosphoinositide breakdown, suggesting that epithelial receptors to tachykinins may be of the NK1 subtype. Since it is established that phosphoinositide derivatives can elicit mobilization of intracellular calcium, our results suggest that phosphoinositide breakdown is the coupling mechanism for tachykinin-induced contraction of airway smooth muscle.
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PMID:Tachykinin-induced phosphoinositide breakdown in airway smooth muscle and epithelium: relationship to contraction. 245 69

Neurokinins are active stimulants of the human isolated urinary bladder. In a preliminary study, performed on bladders taken from four donors, we attempted the characterization of neurokinin receptors. It was shown that neurokinin A is more active than neurokinin B and substance P. Neurokinin receptors selective agonists were also tested and it was found that the most active compound was the NK-A selective agonist, [Nle10]NKA 4-10: A substance P antagonist was able to reduce the effect of neurokinin A but its affinity was rather low. This suggests that the receptor mediating the contraction of the human urinary bladder to neurokinins is of the NK-A (NK2) type. The action of neurokinins on the human urinary bladder appears to be a direct one and mediated by specific receptors different from those of other agents. On the contrary, kinins were found to be active through a new mechanism which was not influenced by either anti-B1 or anti-B2 receptor antagonists.
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PMID:Substance P and neurokinins as stimulants of the human isolated urinary bladder. 245 93


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