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 role of phosphatases in modulating contractile responses to electrical field stimulation (EFS), methacholine, substance P and capsaicin in guinea-pig isolated main bronchus by use of the phosphatase 1 and 2A inhibitor okadaic acid. 2. Non-adrenergic non-cholinergic (eNANC) contractile responses were elicited by EFS (3 Hz, 20 s, 0.5 ms max. voltage) in the guinea-pig isolated main bronchus in the presence of the non-selective muscarinic antagonist, atropine (1 microM), the non-selective beta-adrenoceptor antagonist; propranolol (1 microM), the neutral endopeptidase inhibitor thiorphan (10 microM) and the cyclo-oxygenase inhibitor, indomethacin (5 microM). Okadaic acid significantly attenuated eNANC contractile responses (% inhibition) elicited by EFS (0.01 microM, 15.2 +/- 26.9%; 0.03 microM, 30.4 +/- 13.9%; 0.01 microM, 39.8 +/- 5.1%; 0.3 microM, 59.5 +/- 8.7%; 1 microM 77.8 +/- 7.8%; P < 0.05, n = 4). In contrast, the inactive analogue 1-Nor okadaone (0.3 microM) failed to attenuate significantly eNANC contractile responses (% inhibition elicited by 1-Nor okadaone, -1.25 +/- 8.5% vs dimethylsulphoxide (DMSO), -13.5 +/- 21.5%; P > 0.05, n = 4). 3. Cholinergic contractile responses were elicited by EFS (1-30 Hz, 10 s, 0.5 ms max. voltage) in guinea-pig isolated bronchus in the presence of the nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME, 30 microM). Okadaic acid failed to attenuate significantly the contractile (% methacholine Emax) response elicited by EFS at all frequencies tested compared with the control (1 Hz, control, 22 +/- 7.9% vs okadaic acid, 18 +/- 7.7%; 3 Hz, control, 26 +/- 6.9% vs okadaic acid, 27 +/- 9.1%; 10 Hz, control, 36 +/- 7.6% vs okadaic acid, 33 +/- 8.9%; 30 Hz, control, 50 +/- 7.6% vs okadaic acid, 42 +/- 14%; P > 0.05, n = 4). 4. Okadaic acid (0.3 microM) failed to alter significantly the contractile potency (pD2) to capsaicin (okadaic acid, 9.0 +/- 0.5, vs DMSO, 9.2 +/- 0.4; P > 0.05 n = 6), substance P (okadaic acid, 7.6 +/- 0.3 vs DMSO, 8.2 +/- 0.2; P > 0.05 n = 7) or methacholine (okadaic acid, 6.4 +/- 0.2 vs DMSO, 6.4 +/- 0.3; P > 0.05 n = 4). 5. Okadaic acid (0.01-1 microM) did not appear to reverse substance P-induced tone. The maximal relaxant response (% reversal of substance P-induced tone) mediated by okadaic acid (1 microM) was 33 +/- 11.7% (n = 4), this was not significantly different from the DMSO (0.8%) or a time-dependent fall in tone of 34.3 +/- 23.1% (n = 4) and 33 +/- 15.8% (n = 4), respectively. Okadaic acid (0.3 microM) failed to augment isoprenaline-induced relaxation responses in substance P contracted bronchus (okadaic acid, 6.5 +/- 0.4 vs DMSO, 5.9 +/- 0.3; P > 0.05, n = 9). 6. These results indicate that protein phosphatases appear to regulate the release of sensory neuropeptides from airway sensory nerves in response to electrical field stimulation.
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PMID:The effect of okadaic acid on non-adrenergic non-cholinergic contraction in guinea-pig isolated bronchus. 915 25

The effects of the nitric oxide (NO) synthesis inhibitors, NG-nitro-L-arginine (L-NNA) and NG-nitro-L-arginine methyl ester (L-NAME), on the electrical field stimulation (EFS)-induced inhibitory responses were investigated. EFS caused, in strips contracted by means of substance P (SP), prostaglandin F2 alpha (PGF2 alpha), or carbachol (CCh), a fast relaxant response that, depending on stimulation frequency and strip tension, could be followed by a slower, sustained relaxation. The NO synthesis inhibitors blocked the EFS-induced fast relaxations and often reversed them into contractions; these effects were greatly counteracted in SP- or PGF2 alpha-treated strips by scopolamine or atropine. In CCh-precontracted strips, either L-NNA or L-NAME became progressively unable to block the EFS-induced fast relaxations as the CCh concentration was increased. The NO synthesis inhibitors greatly reduced the sustained relaxant responses elicited either by EFS or exogenous vasoactive intestinal polypeptide (VIP). The results indicate that the NO synthesis inhibitors abolish the neurally induced fast relaxation by interfering with the cholinergic excitatory pathway. The involvement of both VIP and NO in sustained relaxations is also suggested.
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PMID:Nitric oxide as modulator of cholinergic neurotransmission in gastric muscle of rabbits. 927 25

We have tested the vasoactive effects of kinins in addition to various other endothelium-dependent or independent agonists in the arterial and venous perfused mesenteric circuits of the mouse. Bradykinin (0.1 pmol-100 nmol), but not des-Arg9-bradykinin (10 nmol) induced a dose-dependent vasodilation of the precontracted arterial and venous mesenteric vasculature of the mouse. Furthermore, acetylcholine (2.5 nmol) also induced a marked arterial vasodilation but was without effect on the venous side. Other endothelium-dependent vasodilators, such as platelet-activating factor (PAF) (1 nmol), tachykinin NK1 selective agonist ([Sar9,Met(O2)(l1) ]substance P) (0.5 nmol) and adenosine diphosphate (5 nmol), were without effect on either side of the mesenteric bed of the mouse. The bradykinin B2 receptor selective antagonist (HOE 140) abolished the arterial and venous vasodilation induced by bradykinin without affecting that of acetylcholine or sodium nitroprusside. In addition, the bradykinin B1 receptor antagonist des-Arg9-[Leu8]bradykinin was without effect on the responses induced by bradykinin. A nitric oxide synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME) markedly reduced, whereas removal of the endothelium with 3-[3-cholamidopropyl)dimethylammonio]-1-propane sulfonate (CHAPS) abolished dilatation to bradykinin and acetylcholine (arterial side only) without affecting that induced by sodium nitroprusside in the mouse arterial and venous mesenteric circuits. In the same two circuits of transgenic B2 knockout mice, the vasodilatory responses to bradykinin were absent, whereas the arterial circuit still responded to acetylcholine by a L-NAME-sensitive vasodilation. Our results suggest the exclusive contribution of B2 receptors located on the endothelium in the vasodilatory effects of bradykinin in the arterial and venous mesenteric circuits of the mouse.
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PMID:Pharmacology of kinins in the arterial and venous mesenteric bed of normal and B2 knockout transgenic mice. 931 61

Because of the evidence that endogenous nitric oxide (NO) plays an essential role in the physiological regulation of gastrointestinal motility we have investigated, by use of the NO synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME), the role of endogenous NO in the acute endotoxin-induced changes of gastrointestinal transit. Pre-treatment with E. coli endotoxin (100 micrograms kg-1, i.v.) induced a significant increase in the gastrointestinal transit of a charcoal suspension in anaesthetized rats. Previous administration of the NO synthase inhibitor, L-NAME (10 mg kg-1, i.v.) significantly prevented the effects of endotoxin. L-arginine (200 mg kg-1, i.v.) and the substance P antagonist [D-Pro2, D-Trp7,9]-substance P (SPA), significantly reversed the effects of L-NAME on gastrointestinal transit in rats treated with endotoxin. Pre-treatment with dexamethasone (5 mg kg-1, s.c., twice), an inhibitor of the expression of inducible NO synthase, did not affect the increase in the gastrointestinal transit through constitutive NO synthesis. The results suggest that constitutive nitric oxide is involved in the increase of gastrointestinal transit induced by endotoxin and that the reduction in transit induced by L-NAME in endotoxin-treated rats is mediated by endogenous tachykinins.
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PMID:Nitric oxide modulates the acute increase of gastrointestinal transit induced by endotoxin in rats: a possible role for tachykinins. 936 8

1. We investigated the effect of acute inhalation of cigarette smoke on subsequent non-adrenergic, non-cholinergic (NANC) neural bronchoconstriction in anaesthetized guinea-pigs in vivo by use of pulmonary insufflation pressure (PIP) as an index of airway tone. The contribution of endogenous nitric oxide (NO) was investigated with the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). The contribution of plasma exudation to the response was investigated with Evans blue dye as a plasma marker. 2. Inhalation of 50 tidal volumes of cigarette smoke or air had no significant effect on baseline PIP. In the presence of propranolol and atropine (1 mg kg(-1) each), electrical stimulation of the vagus nerves in animals given air 30 min previously induced a frequency-dependent increase in PIP above sham stimulated controls (16 fold increase at 2.5 Hz, 24 fold increase at 10 Hz). In contrast, in smoke-exposed animals, the increase in subsequent vagally-induced PIP was markedly less than in the air controls (90% less at 2.5 Hz, 76% less at 10 Hz). 3. L-NAME (10 mg kg[-1]), given 10 min before air or smoke, potentiated subsequent vagally-induced (2.5 Hz) NANC bronchoconstriction by 338% in smoke-exposed animals, but had no significant effect in air-exposed animals. The inactive enantiomer D-NAME (10 mg kg[-1]) had no effect, and the potentiation by L-NAME was partially reversed by the NO-precursor L-arginine (100 mg kg[-1]). Vagal stimulation did not affect the magnitude of vagally-induced bronchoconstriction 30 min later. 4. Cigarette smoke exposure reduced the magnitude of subsequent bronchoconstriction induced by neurokinin A (NKA) by 37% compared with the effect of NKA in air-exposed animals. L-NAME had no significant effect on the smoke-induced inhibition of NKA-induced bronchoconstriction. 5. Vagally-induced plasma exudation in the main bronchi was greater in smoke-exposed animals compared with air-exposed animals (120% greater at 2.5 Hz, 82% greater at 10 Hz). 6. We conclude that cigarette smoke-induced inhibition of subsequent NANC neurogenic bronchoconstriction is not associated with inhibition of airway plasma exudation and is mediated in part via exogenous smoke-derived NO, or another bronchoprotective molecule, and by endogenous NO.
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PMID:Cigarette smoke-inhibition of neurogenic bronchoconstriction in guinea-pigs in vivo: involvement of exogenous and endogenous nitric oxide. 937 77

This study has investigated the relative involvement of cholinergic, adrenergic, nitric oxide and tachykininergic transmission in extrinsic neural influences on the lower oesophageal sphincter (LOS) in urethane anaesthetized ferrets. A micromanometric assembly (OD 1.75 mm) incorporating a sleeve sensor was used for high-fidelity oesophageal, LOS and gastric pressure measurement at low perfusion rates (< 0.1 ml/min). The LOS response to vagal and splanchnic nerve stimulation (0.5 ms pulse width, 10 s duration) was frequency- and voltage-dependent. LOS responses to stimulation at 20 V, 10 Hz were investigated in separate groups of animals with either L-NAME (100 mg/kg), hexamethonium (15 mg/kg), guanethidine (5 mg/kg), CP96,345 (NK-1 antagonist, 4 mg/kg), atropine (0.4 mg/kg) or propranolol (1 mg/kg). Propranolol treatment was followed by yohimbine (1 mg/kg) and prazosin (0.25 mg/kg). Vagal stimulation caused an immediate decrease in LOS pressure, followed by increase on cessation of stimulation, followed by a prolonged decrease (77 +/- 2%) for up to 5 min. L-NAME did not affect inhibition, but increased excitation 4-fold (p < 0.001). Guanethidine and CP96,345 had no major effect. Hexamethonium decreased the inhibitory (p < 0.05) and excitatory (p < 0.01) responses. Atropine reduced the excitatory response (p < 0.05). Some inhibition still remained if all treatments were combined. Splanchnic stimulation reduced LOS pressure by 70 +/- 6% for 101 +/- 17 s. L-NAME, guanethidine, hexamethonium and CP96,345 all independently significantly reduced inhibition. The combination of guanethidine and CP96,345 usually abolished splanchnic-induced inhibition. Atropine was without effect. Propranolol (1 mg/kg) changed the splanchnic-induced response from mainly inhibition to excitation (100 +/- 44% increase). LOS responses to noradrenaline (1-10 micrograms close IA) showed similar features to responses to splanchnic stimulation. We conclude that vagal stimulation evokes LOS relaxation via activation of established cholinergic and NANC mechanisms and other, unidentified mechanisms. Splanchnic stimulation activates adrenergic neurones probably via nicotinic and non-nicotinic ganglionic mechanisms, which in turn elicit beta adrenergic inhibitory effects on the LOS. Splanchnic stimulation also antidromically activates spinal afferent fibres. These may release substance P from peripheral myenteric plexus and prevertebral ganglionic endings causing activation of myenteric NANC inhibitory neurones and sympathetic neurones, respectively.
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PMID:Vagal and sympathetic influences on the ferret lower oesophageal sphincter. 940 23

Repeated oesophageal acidification is a definitive feature of gastro-oesophageal reflux disease, which in turn is caused by relaxation of the lower oesophageal sphincter (LOS). This study in anaesthetised ferrets investigates the reflex pathways involved in effects of oesophageal acidification on motor function of the LOS, with particular focus on the role of tachykinins. LOS pressure was monitored with a perfused micromanometric sleeve assembly. Oesophageal acidification reduced LOS pressure by 48 +/- 5% until washout with saline. This reduction became larger with repeated tests, and was unaffected in amplitude by acute bilateral vagotomy, although the response became slower in onset. Intra-oesophageal capsaicin (0.5% solution) caused a 68 +/- 17% decrease in LOS pressure which remained unchanged with repeated tests. The NK-1 receptor antagonist CP96,345 (1-5 mg/kg intravenous (i.v.) blocked the post-vagotomy LOS responses to both intra-luminal acid and capsaicin. Close intra-arterial (i.a.) injections of capsaicin (1-100 micrograms) gut induced LOS relaxation which was neither vagally nor NK-1 receptor-mediated. Substance P or the selective NK-1 receptor agonist [Sar9, Met(O2)11] substance P (25-500 ng close i.a.) caused a biphasic LOS response, consisting of initial brief contraction followed by prolonged, dose-dependent relaxation. Tetrodotoxin (10 micrograms/kg close i.a.) changed the biphasic response to substance P to excitation only. The neurokinin-1 (NK-1) receptor antagonist CP96,345 (0.3-10 mg/kg i.v.) dose-dependently reduced the inhibitory response to substance P. The excitatory phase of the response to substance P was larger and prolonged after guanethidine (5 mg/kg, i.v.), or propranolol (1 mg/kg, i.v.). L-NAME (100 mg/kg i.v.) reduced the inhibitory phase. The selective NK-2 receptor agonist [beta-Ala8] neurokinin A(4-10) caused LOS excitation only. These data indicate that intra-oesophageal acid causes substance P release from extrinsic afferent nerve endings which activates local inhibitory pathways to the LOS via NK-1 receptors.
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PMID:Lower oesophageal sphincter responses to noxious oesophageal chemical stimuli in the ferret: involvement of tachykinin receptors. 940 24

Inhalation of cold air in guinea pigs increases total pulmonary resistance (RL), an effect that is mediated by kinins and tachykinins. Bronchoconstriction induced by bradykinin (BK) inhalation in guinea pigs is markedly inhibited by nitric oxide (NO) release from the airway epithelium. We investigated whether endogenous NO modulates the increase in RL induced by inhalation of cold air. In anesthetized and artificially ventilated guinea pigs pretreated with atropine, cold-air inhalation (13 degrees C in the trachea) for 5 min did not increase RL. Pretreatment with intravenous N(G)-nitro-L-arginine methyl ester (L-NAME) (but not with its inactive enantiomer, D-NAME) increased RL, an effect reversed by L-Arg. The increase in RL induced by cold air after L-NAME was abolished by the tachykinin NK2-receptor antagonist SR 48968 or the kinin B2-receptor antagonist, HOE 140. After administration of SR 48968, inhalation of cold air reduced baseline airway tone. However, after HOE 140, cold-air inhalation did not affect baseline airway tone. L-NAME exaggerated the bronchoconstriction induced by BK. However, L-NAME did not affect capsaicin-induced bronchoconstriction. BK increased cyclic guanosine monophosphate (cGMP) levels in strips of guinea pig trachealis muscle in vitro, whereas the selective tachykinin NK2-receptor agonist [betaAla8]neurokinin A (4-10) was without effect. The present data suggest that bronchoconstriction induced by cold-air inhalation and mediated by kinin and tachykinin release is inhibited by endogenous NO, and that kinins, but not tachykinins or cold air alone, release bronchorelaxant NO.
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PMID:Endogenous nitric oxide inhibits bronchoconstriction induced by cold-air inhalation in guinea pigs: role of kinins. 947 71

The stomach normally responds to mucosa-damaging agents by decreasing acid secretion, but this acid response turn from "inhibition" into "stimulation" when the production of nitric oxide (NO) is inhibited by NG-nitro-L-arginine methyl ester (L-NAME). We investigated the mechanism underlying stimulation of acid secretion in the stomach after damage with taurocholate (TC) in the presence of L-NAME. A rat stomach was mounted in an ex vivo chamber and perfused with saline, and the potential difference (PD), luminal pH, and acid secretion were measured before and after application of 20 mM TC for 30 min. Exposure of the stomach to TC caused a reduction in PD, an increase in luminal pH, and a decrease in acid secretion. Pretreatment with L-NAME did not affect basal acid secretion but significantly increased secretion after damage with TC, without any effect on PD. This effect of L-NAME was antagonized by co-administration of L-arginine but not D-arginine. The luminal appearance of NO was also increased after exposure of the stomach to TC, a phenomenon completely blocked by L-NAME, or when EGTA was applied together with TC. The enhanced acid secretory response in the presence of L-NAME was inhibited by prior administration of cimetidine, FPL-52694 (a mast cell stabilizer), spantide (a substance P antagonist), or by chemical ablation of capsaicin-sensitive sensory neurons. Mucosal exposure to TC increased histamine output in the lumen and decreased the number of mucosal mast cells in the stomach. These changes were prevented by FPL-52694 or sensory neuronal ablation. These results suggest that (a) damage in the stomach may activate acid stimulation in addition to an NO-dependent inhibitory mechanism but that the latter effect overcomes the former, resulting in a decrease in acid secretion, (b) acid stimulation in the damaged stomach may be mediated by histamine released from the mucosal mast cells, a process that may interact with capsaicin-sensitive sensory nerves, and (c) L-NAME unmasks the acid stimulatory response by suppressing the inhibitory mechanism.
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PMID:Nitric oxide, histamine, and sensory nerves in the acid secretory response in rat stomach after damage. 947 25

Previous studies have shown that the guinea pig inferior mesenteric artery receives spinal sensory vasodilatory innervation, which can be activated by colon distention and electrical nerve stimulation. In the present study, we investigated the hypotheses that nitric oxide synthase (NOS) is present in guinea pig primary sensory neurons in the dorsal root ganglion (DRG) and in nerve fibers surrounding the mesenteric arteries, and that nitric oxide (NO) is a sensory neurotransmitter in the inferior mesenteric artery in vitro. Double-labeling immunohistochemistry showed that neuronal NOS-IR was found in 12% of cells of guinea pig thoracic and lumbar DRGs; in 95.1% of these cells it was colocalized with substance P (SP), and SP immunoreactivity (SP-IR) was present in 23% of cells of the same DRGs. Neuronal NOS-like immunoreactivity was localized in nerve fibers surrounding guinea pig mesenteric artery and 25% of them were double stained with SP-IR. Endothelium-denuded inferior mesenteric artery preparations in vitro were incubated with guanethidine (30 microns, 30 min) and pre-contracted with methoxamine (30 microns). The NO donors, sodium nitroprusside (1 micron) and L-nitrosocysteine (300 microns), produced 91.0 +/- 5.5 and 90.4 +/- 9.6% vasodilatation of total vasodilatation in the vessel segments, respectively, which was capsaicin- or tetrodotoxin-insensitive. Repetitive electrical field stimulation of the preparations produced a frequency-dependent vasodilatation which was reduced by pretreatment with capsaicin or by tetrodotoxin (10 microns). The NOS inhibitor N omega-nitro-L-arginine (L-NNA) (100 microns, 30 min) diminished the nerve-evoked vasodilatation from 41.8 +/- 8.4 to 21.4 +/- 9.7% at 2 Hz and from 50.8 +/- 5.6 to 19.0 +/- 7.3% at 15 Hz (P < 0.05), whereas NG-nitro-L-arginine methyl ester (L-NAME, 100 microns-1 mM) did not significantly inhibit the relaxation. The stereo isomer nitro-D-arginine (D-NNA, 100 microns, 30 min) was ineffective. These findings suggest that NO is a neurotransmitter released from primary sensory nerves which mediates vasodilation in vitro.
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PMID:Nitric oxide is a sensory nerve neurotransmitter in the mesenteric artery of guinea pig. 947 65


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