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

Neurokinins regulate gastrointestinal motility by interacting with receptors on both muscle layers and on myenteric plexus neurons. To determine if specific neurokinin (NK) receptor agonists can mediate inhibitory effects on myenteric neurons, we studied the effect of the NK-1 agonist substance P methylester (SPME) and the putative endogenous NK-2 receptor ligand neurokinin A (NKA) on [3H]acetylcholine [( 3H]ACh) release induced by electrical field stimulation from muscle strips cut from the canine gastric antrum. SPME but not NKA caused a dose-dependent inhibition of stimulated [3H]ACh release in tissues containing the myenteric plexus. The inhibition was not seen in longitudinal muscle without myenteric plexus. Pretreatment of tissues with indomethacin or antiserum to vasoactive intestinal polypeptide (VIP) but not naloxone or adrenergic or cholingergic blockade abolished the SPME-induced inhibition. Exogenous VIP stimulated the release of prostaglandin E2 (PGE2) from full thickness strips, and both VIP and PGE2 inhibited [3H]ACh release induced by electrical depolarization. These findings suggest that NK-1 receptor agonists can selectively inhibit stimulated [3H]ACh release and that this inhibition may involve the release of VIP and PGE2 from neurons within the myenteric plexus.
 ...
PMID:Neurokinin inhibition of cholinergic myenteric neurons in canine antrum. 168 19

Airway contractile responses to substance P (SP) were examined in isolated adult rabbit bronchial (BSM) and tracheal smooth muscle (TSM) segments. The tissues were placed in organ baths containing modified Krebs-Ringer solution, and isometric contractions to SP were monitored in the presence of phosphoramidon, an inhibitor of neutral endopeptidase (NEP). Under these conditions, BSM segments were significantly more reactive and more sensitive to SP than TSM segments. Removal of SPs cholinergic component with atropine (ATP) eliminated these regional differences in reactivity without affecting sensitivity. In considering the basis for these observations, it has been suggested that SP activates up to three different neurokinin (NK) subset receptors. Accordingly, we examined the regional airway contractile responses to Senktide, a selective NK-3 receptor agonist, and Septide, a selective NK-1 receptor agonist. In the presence of ATR, Senktide was inactive in both BSM and TSM, whereas Septide produced significantly greater contractions in BSM than in TSM. Subsequent desensitization of NK-1 receptors with Septide virtually eliminated the regional differences in airway sensitivity to SP. These findings indicate that 1) endogenous NEP activity can mask significant regional airway differences in SP-mediated contraction; and 2) these latter differences are the result of cholinergic, NK-1, and NK-2 receptor influences.
 ...
PMID:Neurokinin receptors mediating substance P-induced contraction in adult rabbit airways. 168 54

(1) Circularly-oriented muscle strips from the human ileum responded to electrical field stimulation (1-50 Hz) with frequency-related primary relaxation at low frequency and primary contractions at high frequencies of stimulation. Both responses were abolished or markedly reduced by tetrodotoxin (1 microM). (2) Atropine (3 microM) or omega conotoxin (0.1 microM) reduced but dit not abolish contraction to electrical field stimulation and enhanced the relaxation. Omega conotoxin (0.1 microM) did not affect carbachol-induced contraction nor isoprenaline-induced relaxation. (3) Neurokinin A and substance P (1 nM-1 microM) produced a concentration-dependent contraction. The NK-1 receptor selective agonist, [Pro9]SP sulfone and the NK-2 receptor selective agonist [beta Ala8]NKA(4-10) produced a contraction superimposable to that of substance P and neurokinin A, respectively. On the other hand, [MePhe7]-neurokinin B, an NK-3 receptor selective agonist was ineffective up to 1 microM. The response to substance P or neurokinin A was unaffected by atropine (3 microM). (4) Galanin, up to 0.1 microM, produced a weak and inconsistent contraction. (5) Vasoactive intestinal polypeptide (10 nM-1 microM) produced a concentration-dependent relaxation while human alpha calcitonin gene-related peptide exerted a weak and inconsistent relaxant effect. (6) These findings indicate that both cholinergic excitatory and non-cholinergic inhibitory nerves affect the motility of the circular muscle of the human small intestine. Transmitter release from excitatory nerves seems largely mediated by activation of omega conotoxin-sensitive (N-type) calcium channels. Tachykinins exert a potent contractile effect, independently of cholinergic nerves, via NK-1 and NK-2 receptors.
 ...
PMID:Human isolated ileum: motor responses of the circular muscle to electrical field stimulation and exogenous neuropeptides. 169 76

The family of mammalian tachykinin receptors consists of substance P receptor (SPR), neuromedin K receptor (NKR) and substance K receptor (SKR). In this investigation, tissue and regional distributions of the mRNAs for the three rat tachykinin receptors were investigated by blot-hybridization and RNase-protection analyses using the previously cloned receptor cDNAs. SPR mRNA is widely distributed in both the nervous system and peripheral tissues and is expressed abundantly in the hypothalamus and olfactory bulb, as well as in the urinary bladder, salivary glands and small and large intestines. In contrast, NKR mRNA is predominantly expressed in the nervous system, particularly in the cortex, hypothalamus and cerebellum, whereas SKR mRNA expression is restricted to the peripheral tissues, being abundant in the urinary bladder, large intestine, stomach and adrenal gland. Thus, the mRNAs for the three tachykinin receptors show distinct patterns of expression between the nervous system and peripheral tissues. Blot-hybridization analysis in combination with S1 nuclease protection and primer-extension analyses revealed that there are two large forms of SKR mRNA expressed commonly in the peripheral tissues, and two additional small forms of the mRNA expressed specifically in the adrenal gland and eye. These analyses also showed that the multiple forms of SKR mRNA differ in the lengths of the 5' mRNA portions, and that the two small forms of the mRNA, if translated, encode a truncated SKR polypeptide lacking the first two transmembrane domains. This investigation thus provides the comprehensive analysis of the distribution and mode of expression of the mRNAs for the multiple peptide receptors and offers a new basis on which to interpret the diverse functions of multiple tachykinin peptides in the CNS and peripheral tissues.
 ...
PMID:Tissue distribution and quantitation of the mRNAs for three rat tachykinin receptors. 170 Nov 45

We have investigated the possible effect of substance P (SP), a main mediator of neurogenic inflammation, on the growth of capillary vessels in vivo, and on the proliferation of cultured endothelial cells in vitro. Slow release preparations of SP were implanted into the avascular cornea of New Zealand White rabbits and vessel growth was monitored daily through a slit lamp stereomicroscope. SP (1-5 micrograms/pellet) induced a marked neovascularization. A selective NK-1 receptor agonist [beta-Ala4, Sar9, Met(O2)11]-SP(4-11) also induced neovascularization. The addition of SP to serum-free cultured endothelial cells, isolated from bovine adrenals (BACE) and from human umbilical cord veins (HUVE), increased proliferation of both cell lines in a concentration-dependent manner with maximal activity at 10(-8) M (BACE) and 10(-10) M (HUVE). The selective NK-1 receptor agonist induced a similar proliferative action on both cell lines, while the selective NK-2 receptor agonist [beta-Ala8]-NKA(4-10) and the selective NK-3 receptor agonist [MePhe7]-NKB had no significant effect. Two different SP antagonists [D-Pro2, D-Trp7,9]-SP and [D-Pro4, D-Trp7,9,Phe11]-SP (4-11) blocked the response to SP. These findings indicate that SP can directly stimulate the process of neovascularization, probably through induction of endothelial cell proliferation. This hitherto unraveled activity of SP could play a key role in the trophic action produced by activation of the efferent function of peripheral endings of primary sensory neurons.
 ...
PMID:Substance P stimulates neovascularization in vivo and proliferation of cultured endothelial cells. 170 Dec 6

Evidence for the involvement of primary afferent nerves and their associated neuropeptides in in vivo immunologic responses has been based on experiments in rats in which destruction of primary afferent nerves by the sensory neurotoxin capsaicin results in a diminished ability of the animal to mount a primary antibody response to sheep red blood cell (SRBC) antigen. This effect was shown to be reversed by substance P infusion immediately following antigenic stimulation. In this report we show that neurokinin A (NKA) is 12 times more potent than substance P in its capacity to reverse the effects of neonatal capsaicin pretreatment on the antibody response. Neurokinin A has a pD2 of 6.65 compared to 5.98 for substance P. In addition, NKA was more potent than substance P in reversing the effects of surgical lesions 2 days prior to antigenic stimulation. The effects of the D- and L-Pro9 analogues of [Glp6, Pro9]-SP6-11 on the plaque-forming cell response in capsaicin-treated rats provide further support for the hypothesis that the tachykinin receptor modulating the primary antibody response is an NK-2 receptor. These results demonstrate, for the first time, a role for NKA in in vivo immunomodulation.
 ...
PMID:Tachykinin-mediated modulation of the primary antibody response in rats: evidence for mediation by an NK-2 receptor. 170 44

Functional cDNA clones for human NK-2 receptor were isolated from human lung RNA using a polymerase chain reaction (PCR) based method (RACE-PCR). In this method the cDNA was isolated as 5' end and 3'-end fragments; the entire cDNA was obtained by RNA-PCR. The sequence derived was 398 amino acids in length encoding an open-reading frame that was highly homologous to both the bovine and rat NK-2 receptor. The entire human cDNA sequence was cloned into a mammalian expression vector and mRNA was synthesised by in vitro transcription. Applications of tachykinins caused membrane current responses in Xenopus oocytes injected with the in vitro synthesised mRNA. The most potent of the three tachykinin peptides tested was neurokinin A. We have screened a human cosmid library and isolated a clone which contains the entire NK-2 receptor gene. The gene contains five exons and we have determined the complete sequence of the exons and the intron-exon junctions.
 ...
PMID:Isolation and characterisation of the human lung NK-2 receptor gene using rapid amplification of cDNA ends. 171 Apr 56

We compared the ability of spantide I and II to antagonize tachykinins in monoreceptor bioassays. Both peptides antagonized the response to substance P methylester in the guinea-pig ileum (NK-1 receptor-mediated) with greater affinity than the responses mediated by NK-2 or NK-3 receptors in other bioassays. Spantide II was about 10 times more potent than spantide I as an NK-1 antagonist and also possessed some selectivity for the NK-2 receptor subtype present in the hamster trachea. Spantide II is a suitable tool to assess the role of NK-1 receptors in the central and peripheral nervous system.
 ...
PMID:Activity of spantide I and II at various tachykinin receptors and NK-2 tachykinin receptor subtypes. 171 73

We identified clones encoding a Drosophila receptor for tachykinin-like peptides by low stringency screening of an embryonic cDNA library with probes from the bovine substance K receptor. The cDNAs encode a seven transmembrane domain protein (DTKR) of 519 amino acids with 40-48% amino acid identity to mammalian tachykinin receptors within transmembrane regions. Xenopus oocytes injected with DTKR cRNAs showed selective responses to vertebrate substance P, its agonists and not to other vertebrate tachykinin peptides. These responses were eliminated by treatment of oocytes with pertussis toxin. In the adult fly, Northern and PCR analysis demonstrated preferential expression of DTKR in the head; in situ hybridization indicated that DTKR is accumulated in the cell bodies of neurons in the adult CNS. The levels of DTKR transcript are regulated during development. Northern and PCR amplification analysis showed that while DTKR transcripts are present at all stages, high levels of expression occur in later stages of embryogenesis (starting at 10-14 h), coinciding with the beginning of major periods of neural development. Whole mount embryo in situ hybridization demonstrated that DTKR is expressed at these later stages of embryogenesis (11-15 h) in the brain and in a specific subset of neurons in each neuromere of the developing ventral ganglion. The gene encoding DTKR was mapped by in situ hybridization to a single location at 99D on the right arm of chromosome 3. These observations demonstrate that the tachykinin family of peptide transmitters and their receptors represent an evolutionarily ancient form of cellular communication within the nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Cloning, heterologous expression and developmental regulation of a Drosophila receptor for tachykinin-like peptides. 171 63

C6-2B rat glioma cells were stably transfected with substance K receptor cDNA and used to study interactions between cAMP and Ca2+ signaling pathways. Activation of the newly expressed receptors by substance K increased the intracellular free Ca2+ concentration, as monitored by single-cell fura-2 imaging, and markedly inhibited agonist-stimulated cAMP accumulation. Blockade of intracellular Ca2+ mobilization abolished the substance K receptor-mediated inhibition of isoproterenol-induced cAMP production. Phosphodiesterase inhibitors, down-regulation or inhibition of protein kinase C, and pertussis toxin failed to prevent substance K-induced inhibition of agonist-stimulated cAMP accumulation. An increased intracellular Ca2+ concentration caused by either calcium ionophores or activation of endogenous bradykinin receptors was found to markedly reduce cAMP production in wild-type cells. These results demonstrate that elevated intracellular Ca2+ concentration can negatively modulate agonist-stimulated adenylate cyclase activity in C6-2B glioma cells.
 ...
PMID:Inhibition of cAMP accumulation by intracellular calcium mobilization in C6-2B cells stably transfected with substance K receptor cDNA. 171 1


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>