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)

In the present study, dactinomycin (10(-5) M) inhibited the non-adrenergic, non-cholinergic bronchoconstriction upon antidromic vagal nerve stimulation (1 Hz for 1 min) in the isolated perfused guinea-pig lung by 84%. The release of calcitonin gene-related peptide was unchanged, however, suggesting a postjunctional action. Dactinomycin (10(-5), 5 x 10(-5) M) also reduced non-adrenergic non-cholinergic bronchial contractions (maximally by 75%) induced by electrical field stimulation or capsaicin, while the cholinergic component and non-adrenergic non-cholinergic relaxation remained intact. The neurokinin-2 receptor antagonist L-659,877 (10(-6) M) had a similar effect as dactinomycin, inhibiting the non-adrenergic non-cholinergic bronchial contractions by 69%, while the neurokinin-1 receptor antagonist CP-96,345 (10(-6) M) had no effect. The bronchoconstriction evoked by neurokinin A, the selective neurokinin-2 receptor agonist Nle10neurokinin A (4-10) and capsaicin was markedly inhibited by dactinomycin while the contraction induced by substance P (SP), the selective neurokinin-1 receptor agonist Sar9Met(O2)11SP, endothelin-1 and acetylcholine was not affected. In autoradiographic experiments on guinea-pig lung, [125I]neurokinin A-labelled sections showed dense binding in the bronchial smooth muscle layer. Dactinomycin inhibited the specific binding of [125I]neurokinin A in a concentration-dependent manner (IC50 = 6.3 x 10(-6) M) and 66% of [125I]neurokinin A total binding was inhibited by 10(-4) M dactinomycin. In the rat colon, [125I]neurokinin A binding to neurokinin-2 sites on circular smooth muscle was inhibited by dactinomycin with an IC50 value of 7.9 x 10(-6) M. Dactinomycin failed to reduce increased nerve-evoked contractions or those caused by Nle10neurokinin A (4-10) per se in the rat vas deferens, which are considered to be mediated by neurokinin-2 receptor activation. In the rat portal vein, dactinomycin did not influence the contractions caused by the neurokinin-3 selective agonist Pro7neurokinin B. In conclusion, dactinomycin selectively inhibited neurokinin-2 receptor activation in guinea-pig lung and rat colon, but not in rat vas deferens, which may depend on the existence of different neurokinin-2 receptor subtypes. Neurokinin A is most likely the main endogenous excitatory non-adrenergic non-cholinergic transmitter in guinea-pig bronchi.
...
PMID:Selective inhibition by dactinomycin of NANC sensory bronchoconstriction and [125I]NKA binding due to NK-2 receptor antagonism. 131 11

The presence of N-terminally extended forms of neurokinin A has recently been reported in the mammalian brain. Among them, gamma-preprotachykinin-(72-92)-peptide amide [gamma-PPT-(72-92)-NH2], a peptide derived by posttranslational processing of gamma-preprotachykinin, is most prominent. We report here that this peptide most likely acts on neurokinin-2 receptor sites since neurokinin A (a putative neurokinin-2 agonist) and gamma-PPT-(72-92)-NH2 are potent competitors of 125I-labeled gamma-PPT-(72-92)-NH2 binding whereas selective neurokinin-1 and -3 agonists are not. Moreover, the distribution of 125I-labeled gamma-PPT-(72-92)-NH2 and 125I-labeled neurokinin A binding sites are very similar in rat brain. On the other hand, 125I-labeled Bolton-Hunter-substance P (a neurokinin-1 ligand) and 125I-labeled Bolton-Hunter-eledoisin (a neurokinin-3 ligand) binding sites are differentially located in this tissue. Thus, it appears that gamma-PPT-(72-92)-NH2 binds to neurokinin-2 receptors and should be considered as a putative endogenous ligand for this receptor class.
...
PMID:gamma-Preprotachykinin-(72-92)-peptide amide: an endogenous preprotachykinin I gene-derived peptide that preferentially binds to neurokinin-2 receptors. 168 55

The present experiments were designed to test the effect of tachykinins and neurokinins on release of somatostatin-like immunoreactivity (SLI) from the isolated perfused stomach. Physalaemin, substance P, kassinin, eledoisin, neurokinin A and neurokinin B inhibited basal SLI release in a dose-dependent manner (1 X 10(-9) to 1 X 10(-7) M). Among all the peptides, physalaemin and substance P were the least potent, whereas kassinin, eledoisin, neurokinin A and B were the more potent compounds in suppressing SLI release. It is proposed that this inhibitory action of tachykinins and neurokinins was mediated by the substance P-K or neurokinin-2 receptor subtype in which kassinin, neurokinin A and eledoisin have been shown to be the more potent agonists. The present study also showed that the effect of neurokinin A, neurokinin B and kassinin was not due to an action involving release of acetylcholine as cholinergic antagonists did not block the SLI inhibitory effect. This suggests that these peptides acted directly on somatostatin containing D-cells.
...
PMID:Inhibitory actions of tachykinins and neurokinins on release of somatostatin-like immunoreactivity from the isolated perfused rat stomach. 245 81

The rat spinal cord with connected dorsal root ganglia was used to study neurokinin and N-methyl-D-aspartate receptors involved in the sensory synaptic transmission of dorsal horn cells. Selective C-fibre excitation was produced by capsaicin (200-500 nM) administered to the dorsal root ganglions. Sixty-nine per cent of dorsal horn cells responded with a postsynaptic depolarization and enhanced synaptic activity, recorded via intracellular electrodes, to capsaicin-activated primary afferent input. Dorsal horn neurons activated by the capsaicin-evoked input were also excited by a 1-min perfusion of the neurokinin-1 receptor agonists substance P methyl ester or GR73 632 and by the neurokinin-2 agonist neurokinin-A. These cells were also depolarized by N-methyl-D-aspartate. Responses to substance P methyl ester and GR73 632 were selectively reduced by the neurokinin-1 receptor antagonist CP96,345, and responses to neurokinin-A were completely blocked by the neurokinin-2 receptor antagonist MEN10 376. The depolarization evoked by N-methyl-D-aspartate was not altered by either of the antagonists, but was completely blocked by the selective N-methyl-D-aspartate receptor antagonist (-)-2-amino-5-phosphonovaleric acid. Capsaicin-evoked responses in the dorsal horn were inhibited by MEN10,376 (63 +/- 13% inhibition) but no significant change was observed with CP96,345. The N-methyl-D-aspartate receptor antagonist (-)-2-amino-5-phosphonovaleric acid consistently inhibited the capsaicin-induced response by 76 +/- 14%. Combination of (-)-2-amino-5-phosphonovaleric acid and MEN10,376 produced an almost complete abolition of the capsaicin-evoked depolarization.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The role of neurokinin and N-methyl-D-aspartate receptors in synaptic transmission from capsaicin-sensitive primary afferents in the rat spinal cord in vitro. 768 Jul 98

Substance P (SP) was recognized to stimulate cell growth. The mechanisms of growth control by SP are unknown. We, therefore, investigated mechanisms of the effect of SP on proliferation of human skin fibroblasts. SP did not stimulate proliferation of fibroblasts growth arrested by serum starvation over 48 hours. However, in the presence of acetylsalicylic acid SP potently stimulated fibroblast growth. A bell-shaped dose-response curve with maximal stimulation at picomolar concentrations was found. Specificity of the mitogenic effect was analyzed by use of synthetic SP analogs. Only neurokinin-1 receptor agonists were active, whereas a specific neurokinin-2 receptor analog did not exhibit mitogenicity. Analyzing the supernatants of growth-arrested fibroblasts treated with SP indicated that SP provokes release of the arachidonic acid metabolites, prostaglandin E2, and prostacyclin but not thromboxane B2 or leukotriene B4. Since similar response patterns in proliferation and arachidonic acid metabolite release have been described for several proinflammatory cytokines, some of which are known to act as competence factors in proliferation, we characterized the mitogenic effect of SP. Results established that SP stimulates fibroblast growth in a manner typical of competence factors. We conclude that arachidonic acid metabolites are involved in the cell cycle-dependent mitogenic action of SP on human skin fibroblasts.
...
PMID:Substance P: a competence factor for human fibroblast proliferation that induces the release of growth-regulatory arachidonic acid metabolites. 768 72

Tachykinins are highly concentrated in striatum and substantia nigra. Intranigral injection of selective neurokinin-1 and neurokinin-3 but not neurokinin-2 receptor agonists significantly decreased striatal dopamine metabolism at early time points (1 and 5 min) but increased dopamine metabolism at late time points (60 and 180 min). This probably modified striatal dopamine release, was, however, not able to influence striatal preprotachykinin-A gene expression. The data suggest that tachykinins modulate nigro-striatal dopamine neurons via neurokinin-1 and neurokinin-3 receptors and the modified dopamine stimulus is not strong enough to influence striatal tachykinin neurons.
...
PMID:Intranigral injection of selective neurokinin-1 and neurokinin-3 but not neurokinin-2 receptor agonists biphasically modulate striatal dopamine metabolism but not striatal preprotachykinin-A mRNA in the rat. 769 97

With the goal of obtaining sufficient functional protein for structural analysis, rat neurokinin-2 receptor was produced in Escherichia coli by linking it to the periplasmic maltose-binding protein. As a first step, we present a biochemical and pharmacological investigation of the recombinant receptor. Western-blots showed that the fusion protein was associated with the membranes. The agonist [4,5-3H-Leu9]neurokinin A and the NK-2 antagonist [3H]SR48,968 bound to the receptor in a highly specific manner. Saturation binding of the [3H]agonist demonstrated a single class of receptors (KD = 10.5 nM, Bmax = 2.5 pmol/mg protein). The [3H]antagonist bound with higher affinity to a larger receptor population (KD = 0.2 nM, Bmax = 7.2 pmol/mg protein). Competition of [3H]agonist binding with other agonists demonstrated a potency order of: neurokinin A > [Nle10]NKA(4-10) = [beta-Ala8]NKA(4-10) >> substance P >>> senktide Against the [3H]antagonist, agonists were only partially inhibitory. Selective NK-2 antagonists inhibited binding of both [3H]ligands with an identical order of potency: SR48,968 >> R396 > MEN10,376, which is consistent with NK-2 receptor pharmacology in rat tissue.
...
PMID:Expression of rat NK-2 (neurokinin A) receptor in E. coli. 771 7

The possible involvement of tachykinin neurokinin-1 and neurokinin-2 receptors in the activation of various micturition-related reflexes was assessed by the intrathecal administration of selective neurokinin-1 or neurokinin-2 receptor antagonists at lumbosacral spinal cord level in urethane-anaesthetized rats. The effect of the glutamate N-methyl-D-aspartate receptor antagonist, 2-amino-5-phosphonovaleric acid, was also investigated for comparison. The effect of antagonists was investigated on: (i) the chemonociceptive vesicovesical reflex activated by topical application of capsaicin onto the urinary bladder; (ii) the distension-induced micturition reflex produced by transvesical filling with saline; (iii) distension-induced rhythmic bladder contractions in isovolumetric conditions (urethra-ligated rats); and (iv) the somatovesical excitatory reflex caused by noxious perineal pinching. The neurokinin-2 receptor selective antagonists MEN 10,376 and SR 48,968 were ineffective in the three models in all doses tested. Selective neurokinin-1 receptor antagonists blocked the chemonociceptive reflex produced by topical application of capsaicin with the rank order of potency (lowest effective dose in brackets): GR 82,334 (1 nmol/rat) > RP 67,580 (10 nmol/rat) > (+/-)CP 96,345 (100 nmol/rat). Unlike GR 82,334, RP 67,580 (10 nmol/rat) and (+/-)CP 96,345 (100 nmol/rat) were also effective on the distension-induced micturition reflex elicited by transvesical filling. Similarly, distension-induced rhythmic contractions were inhibited by RP 67,580 (10 nmol/rat) and (+/-)CP 96,345 (100 nmol/rat) whereas the effect of GR 82,334 was not significant. RP 68,651, the enantiomer of RP 67,580 devoid of neurokinin-1 receptor blocking activity, was inactive in both models. 2-Amino-5-phosphonovateric acid (250 nmol/rat) blocked the three types of vesicoexcitatory reflexes. Intravenous administration of (+/-)CP 96,345, RP 67,580 or 2-amino-5-phosphonovateric acid at the same doses proven effective after the intrathecal route, had no effect on distension-induced rhythmic contractions. To ascertain whether the effect of neurokinin-1 receptor antagonists or 2-amino-5-phosphonovaleric acid may be related to a blockade of tachykinins released from capsaicin-sensitive primary afferent neurons, the effect of RP 67,580 was investigated on the distension-evoked micturition reflex in capsaicin-pretreated rats. Capsaicin pretreatment (50 mg/kg, subcutaneously, four days before) increased bladder capacity. RP 67,580 was no longer effective in capsaicin-pretreated rats. In contrast, 2-amino-5-phosphonovateric acid produced a further increase in bladder capacity in capsaicin-pretreated rats. We conclude that tachykinin neurokinin-1 but not neurokinin-2 receptors are involved in the activation of vesicoexcitatory micturition-related reflexes in the rat spinal cord.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:Evidence for a role of tachykinins as sensory transmitters in the activation of micturition reflex. 810 62

Dactinomycin has recently been shown to be a competitive neurokinin-2 receptor antagonist in addition to its inhibiting action on DNA replication. We investigated in the isolated guinea-pig bronchi the action of 3 Dactinomycin analogues on the contractions evoked by the selective neurokinin-2 receptor agonist [Nle10] neurokinin A(4-10). These analogues included 4,4'-Gly-Dactinomycin and the single peptide lactone of dactinomycin which are inactive on DNA replication and 5,5'-MeLeu-Dactinomycin, which has potent antitumour activity. Independently of their known effect on DNA replication, the three analogues showed neurokinin-2 antagonistic activity which was lower than for Dactinomycin.
...
PMID:Dactinomycin analogues as neurokinin-2 receptor antagonists. 815 53

Functional cDNA clones for hamster neurokinin-2 receptor (NK-2R) were isolated from hamster urinary bladder using a polymerase chain reaction-based methodology. The hamster NK-2R consists of 384 amino acids with a relative molecular weight of 43,418. Hamster NK-2R shares significant amino acid sequence homology with other tachykinin receptors, particularly with rat, bovine, and human NK-2R (94.3, 84.4, and 86.5%, respectively). To examine the pharmacology of cloned hamster NK-2R, we transfected mouse erythroleukemia cells with this receptor, prepared high speed membranes, and studied the receptor properties utilizing the ligand [4,5-3H-Leu9]NKA in a receptor-binding assay. For pharmacological comparison, we also transfected the human NK-2R into mouse erythroleukemia cells. [3H]NKA bound to hamster NK-2R receptor in a protein-dependent, high affinity (Kd1 = 4.14 +/- 0.31 nM), saturable (Bmax1 = 679 +/- 26 fmol/mg of protein), and highly specific manner (89 +/- 2%). A smaller population (10% density) of lower affinity receptors (Kd2 = 150 +/- 92 nM), was also observed in competition experiments. [3H]NKA bound to the human receptor with significantly higher affinity and overall greater receptor density (Kd1 = 0.37 +/- 0.11 nM, Bmax1 = 234 +/- 175 fmol/mg of protein; Kd2 = 9.0 +/- 2 nM, Bmax2 = 1989 + 990 fmol/mg of protein). [3H]NKA binding to both hamster and human receptors was enhanced greatly by divalent cations, whereas GTP analogs weakly inhibited binding to hamster receptor, but potently inhibited binding to the human receptor. Competition experiments with agonists demonstrated binding to high and low affinity states of NK-2 receptors, with identical order of potency in hamster or human NK-2R; NKA > [Nle10]NKA(4-10) > [beta-Ala8]NKA(4-10) >> substance P >>> Senktide. However, remarkable differences were observed in studies with selective NK-2 antagonists (hamster, SR48,968 > L659,877 > R396 >> MEN10,376 versus human, SR48,968 > MEN10,376 > L659,877 > R396). The rank order of antagonist affinity is consistent with the observations of NK-2 receptor pharmacology in the native tissues.
...
PMID:Isolation and pharmacological characterization of a hamster urinary bladder neurokinin A receptor cDNA. 830 85


1 2 3 4 Next >>