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Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The role of nerve-induced release of nitric oxide (NO) as a modulator of neuroeffector transmission was studied in the longitudinal muscle of the guinea pig colon. The biological activity of a vascular relaxing factor released by nerve stimulation was examined in a bioassay cascade system. Furthermore, biochemical measurements of nerve-induced release of the NO metabolite nitrite (NO2-) were made with a chemiluminescence technique. Transmural nerve stimulation elicited contractile responses that were partly blocked by atropine and further inhibited after additional application of the
tachykinin
receptor antagonist CP-96, 345. The NO-synthase inhibitor N omega-nitro-L-arginine (NOARG) enhanced the nerve-induced contractions and concomitantly increased the basal degree of contraction ('tone'). The relaxations obtained by nerve stimulation after treatment with atropine and histamine were inhibited by NOARG. Electrical stimulation of the guinea pig colon released a non-adrenergic non-cholinergic (NANC) vascular relaxing factor into the tissue superfusate. The half-life of this factor down the cascade was the same as that observed with exogenous application of NO NOARG and tetrodotoxin (TTX) inhibited the release of the relaxing factor. During transmural nerve stimulation there was a significant increase in NO/NO2- release. This increase was inhibited by TTX and N omega-nitro-L-arginine methyl ester (L-
NAME
). In conclusion, pharmacological analysis as well as bioassay and biochemical measurements suggest that NO is released during nerve stimulation in the guinea pig colon, where it mediates smooth muscle relaxation.
...
PMID:Nitric oxide-like activity in guinea pig colon as determined by effector responses, bioassay and chemiluminescence analysis. 753 96
The protective action of mild irritants has been established. However, the mechanisms as to how they antagonize the injurious action produced by the subsequent challenge with an ulcerogenic stimulus are still unclear. The present study examined the different protective mechanisms of an oral administration of the three mild irritants, 20% ethanol, 0.3 mol/L HCl or 5% NaCl against the gastric injurious actions of absolute ethanol in rats. In an attempt to clarify the pathways and mediators involved in the adaptive cytoprotection, [D-Pro2, D-Trp7,9]-
substance P
(
substance P
antagonist), Nw-nitro-L-arginine methyl ester (L-
NAME
), indomethacin, capsaicin, lidocaine, atropine or hexamethonium was given. The protective action of 20% ethanol but not the other two mild irritants, was antagonized by L-
NAME
, indomethacin and capsaicin, which are the inhibitors of nitric oxide (NO) and prostaglandins (PG) synthesis, and afferent sensory neuron blocker, respectively.
Substance P
antagonist, lidocaine or atropine given alone, prevented mucosal damage; however, only
substance P
antagonist enhanced the anti-lesion action of 20% ethanol, while atropine and lidocaine increased the protective effect of NaCl and HCl. The three mild irritants increased the residual gastric secretion. Only 20% ethanol and 5% NaCl but not 0.3% HCl significantly increased the basal adherent mucus and also attenuated the mucus depletion by absolute ethanol. It is concluded that the cytoprotective action of either ethanol or NaCl seems to be mediated through the increase of residual gastric secretion and adherent mucus. In the ethanol-treated group, these actions could act through the afferent sensory fibres, with NO and PG as the possible mediators.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:The differential mechanisms of mild irritants on adaptive cytoprotection. 753 52
The goal of these studies was to examine the effects of
substance P
, a
tachykinin
neuropeptide, on pathways of microvascular permeability. Individual frog mesenteric venular capillaries were cannulated, and albumin apparent permeability coefficients (Ps) were determined by quantitative fluorescence microscopy. Ps of albumin (PsAlb) rose from 6.8 +/- 1.8 (SE) cm.s-1.10(7) at control to 22.3 +/- 2.3 cm.s-1.10(7) when
substance P
(10(-11) M) was perfused. The effect of increased microvessel permeability induced by
substance P
(10(-11) M) was blocked with the nonpeptide substance P receptor antagonist CP-96,345 and NG-nitro-L-arginine methyl ester (L-
NAME
), an inhibitor of nitric oxide synthase. PsAlb increased 0.99 cm.s-1.10(7) for every cmH2O increase in microvessel pressure after treatment of the vessel with
substance P
, demonstrating coupling of albumin flux to transvascular water flow. In conclusion, the mechanism of increased microvessel permeability in response to
substance P
appears to be the result of receptor-mediated increase in nitric oxide production and formation of water-filled convective pathways presumably located between adjacent endothelial cells.
...
PMID:Substance P increases microvascular permeability via nitric oxide-mediated convective pathways. 753 70
Evidence from our previous work suggests that neurogenic mediators contribute to the inflammation following ultraviolet (UV) irradiation of the skin. We have investigated whether calcitonin gene-related peptide (CGRP),
substance P
and nitric oxide (NO) participate in the cutaneous inflammatory reaction of the rat hind paw and ear to UV irradiation. Skin blood flow was measured by laser Doppler technique. Oedema was quantified using a spring loaded micrometer to measure ear thickness. UV irradiation of the rat skin lead to a long lasting increase in skin blood flow. This increase was dose dependently attenuated by the CGRP receptor antagonist CGRP-(8-37) (0.15 nmol in 25 microliters to 6.0 nmol in 25 microliters, s.c.) up to 51% with a maximum of effectiveness at 24 h post irradiation. The inhibitor of NO synthase NG-nitro-L-arginine methyl ester hydrochloride (L-
NAME
, 25 nmol in 25 microliters, s.c.) attenuated skin blood flow by 38%. Concurrent injections s.c. of CGRP-(8-37) (1.5 nmol in 12.5 microliters) and L-
NAME
(25 nmol in 12.5 microliters) demonstrated an augmentive effect in attenuating skin blood flow. The
tachykinin
NK1 receptor antagonist CP-96,345 (6.0 nmol in 25 microliters, s.c.) attenuated skin blood flow by 27%. NG-Nitro-D-arginine methyl ester hydrochloride (D-
NAME
) and CP-96.344 showed no effects on skin blood flow after UV irradiation. CGRP-(8-37) (0.6 nmol in 10 microliters) i.d. and L-
NAME
(10 nmol in 10 microliters) i.d. had no effect of oedema formation after UV irradiation. Furthermore, post UV irradiation enhanced CGRP- and NO synthase-immunoreactivity in nerve fibres in the exposed skin area were visible. Taken these findings together we suggest the involvement of the neuropeptides CGRP and
substance P
and of neuronal NO on the vasodilatory component of the UV-induced inflammatory reaction of the rat skin. CGRP contributing to UV-induced vasodilation acts in an endothelial NO-independent manner.
...
PMID:Calcitonin gene-related peptide, substance P and nitric oxide are involved in cutaneous inflammation following ultraviolet irradiation. 754 83
To examine the effect of tachykinins on Cl secretion across tracheal mucosa and the possible contribution of nitric oxide (NO) formation to their actions in vivo, we measured Cl diffusion potential difference (Cl-PD) with a high-impedance voltmeter in the presence of amiloride. Superfusion of each
neurokinin A
(
NKA
) and
substance P
(SP) increased Cl-PD in a concentration-dependent fashion, whereas neurokinin B (NKB) had no effect, with the rank order of potency being
NKA
> SP >> NKB. The
tachykinin
-induced increase in Cl-PD was inhibited by the NO synthase inhibitor NG-nitro-L-arginine methylester (L-
NAME
), an effect that was reversed by L-arginine but not by D-arginine. These results suggest that tachykinins increase Cl secretion across rabbit trachea from the submucosa toward the lumen via stimulation of NK2 receptors and that NO formation may be involved in at least part of this process.
...
PMID:[Role of nitric oxide in tachykinin-induced increase in Cl diffusion potential difference of rabbit tracheal mucosa]. 759 41
1. We investigated the effect of the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (L-
NAME
) and the peptidase alpha-chymotrypsin on non-adrenergic, non-cholinergic (NANC neural) bronchoconstriction induced by electrical stimulation of the vagus nerves and by capsaicin in anaesthetized guinea-pigs in vivo using pulmonary insufflation pressure (PIP) as an index of bronchial tone. We also investigated the contribution of soluble guanylyl cyclase (SGC) to NANC neural relaxant mechanisms. 2. In the presence of atropine and propranolol, electrical stimulation of the vagus nerves induced a frequency-dependent increase in PIP above baseline of 67% at 2.5 Hz, of 128% at 5 Hz and of 230% at 10 Hz. L-
NAME
(1-50 mg kg-1, i.v.), at doses inducing increases in systemic blood pressure, dose-relatedly potentiated NANC bronchoconstriction. At 10 mg kg-1 i.v., L-
NAME
significantly (P < 0.05) potentiated NANC bronchoconstriction by a further 106% at 2.5 Hz and a further 147% at 5 Hz but did not potentiate the increase in PIP at 10 Hz. L-
NAME
did not induce bronchoconstriction in sham-stimulated control animals. D-
NAME
did not potentiate NANC bronchoconstriction. Raising systemic blood pressure with phenylephrine did not potentiate vagally-induced bronchoconstriction (2.5 Hz). 3. The NO precursor L-arginine, but not D-arginine, (100 mg kg-1, i.v.) significantly reversed the potentiation by L-
NAME
of NANC bronchoconstriction. L-Arginine alone significantly inhibited neurogenic bronchoconstriction at 10 Hz (by 74%); the inhibition of 25% at 2.5 Hz was not significant. 4. L-
NAME
did not significantly affect the increases in PIP induced by intravenous
substance P
.
neurokinin A
(
NKA
) or capsaicin. 5. The inhibitor of SGC, methylene blue (10 mg kg', i.v.) potentiated (by 110-140%) NANC neural bronchoconstriction induced by lower frequencies of nerve stimulation and reversed the reduction in PIP induced by the SGC activator, sodium nitroprusside (SNP, 1.05 mg kg- 1, i.v.). SNP significantly (P <0.05) reduced by 65% the bronchoconstriction induced by nerve stimulation at 10 Hz. Methylene blue did not effect baseline PIP in sham-stimulated controls. The airway effects of methylene blue and SNP were not associated with their cardiovascular effects. 6. a-Chymotrypsin (2 units kg-', i.v.) significantly potentiated vagally-induced bronchoconstriction by a further 63% at 2.5 Hz, by a further 95.6% at 5 Hz but did not potentiate the increase in PIP at 10 Hz. alpha-Chymotrypsin also potentiated (by 116%) capsaicin-induced bronchoconstriction. Vasoactive intestinal peptide (VIP, 10 ig kg-' i.v. infused over min) significantly reduced by 70% the increase in PIP induced by
NKA
(0.1 .Lmol kg-' i.v., infused over 30 s). 7. The combination of a-chymotrypsin (2 units kg-', i.v.) and L-
NAME
(5 mg kg-', i.v.) significantly potentiated NANC bronchoconstriction by a further 304% at 2.5 Hz, an increase in PIP which was greater than that induced by either a-chymotrypsin or L-
NAME
alone (P <0.05). 8. We conclude that endogenous NO and a bronchodilator peptide, possibly VIP, released in association with nerve stimulation, as well as activation of soluble guanylyl cyclase, regulate the magnitude of NANC neurogenic bronchoconstriction in guinea-pigs in vivo.
...
PMID:Regulation of NANC neural bronchoconstriction in vivo in the guinea-pig: involvement of nitric oxide, vasoactive intestinal peptide and soluble guanylyl cyclase. 767 32
Increased release of endothelium-derived relaxing factor/nitric oxide has been proposed as the final common pathway for vasodilator responses to gram-negative lipopolysaccharide (endotoxin). To test this hypothesis, we examined endothelium-dependent and endothelium-independent vasodilator agents in vascular smooth muscle isolated from guinea pigs 16 hours after injection of saline (control group) or induction of Escherichia coli endotoxemia; aortic rings (approximately 1 mm in diameter) were studied with standard isometric tension techniques. Endotoxemia resulted in a significant loss of vasodilator responses to the endothelium-dependent receptor agonists acetylcholine (10(-10)-10(-5) M) and ADP (10(-8)-10(-5) M). In contrast, endotoxemia did not affect vasodilator responses to either the endothelium-dependent receptor agonist
substance P
(10(-11)-10(-7) M), the endothelium-dependent and receptor-independent agonist A23187 (10(-9)-10(-6) M), or the endothelium-independent agonist nitroprusside (10(-10)-10(-4) M). The nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-
NAME
) inhibited the vasodilator response to acetylcholine more in vessels from lipopolysaccharide-injected than control guinea pigs. Unexpectedly, L-
NAME
converted the endothelium-dependent vasodilator action of ADP to an endothelium-dependent vasoconstrictor response that was blocked individually by the cyclooxygenase inhibitor indomethacin, the thromboxane synthase inhibitor dazoxiben, and the thromboxane A2 receptor antagonist SQ29548. We conclude that in vivo endotoxemia inhibits the constitutive isoform of nitric oxide synthase in endothelial cells by selectively disrupting receptor-coupled activation mechanisms shared by acetylcholine and ADP. Furthermore, since L-
NAME
unmasks a thromboxane A2-mediated vasoconstrictor action of the endogenous purinoceptor agonist ADP, drugs that inhibit nitric oxide synthase could exacerbate sepsis-induced vasoconstriction and ischemia by synergizing with lipopolysaccharide-induced inhibition of endothelial nitric oxide synthase.
...
PMID:Selective inhibition of endothelium-dependent vasodilator capacity by Escherichia coli endotoxemia. 767 34
Responses to
substance P
were investigated in the pulmonary vascular bed of the cat with controlled pulmonary blood flow and constant left atrial pressure. Under baseline conditions, intralobar injections of
substance P
caused small, inconsistent reductions in lobar arterial pressure (AP) and significant reductions in mean systemic AP without affecting left atrial pressure. Decreases in lobar AP were significant and dose related when lobar vascular resistance was increased with U-46619, a thromboxane A2 mimetic. When compared with other vasodilator agents, the order of potency was
substance P
approximately bradykinin > pituitary adenylate cyclase activating polypeptide (PACAP) > acetylcholine (in nmol). Pulmonary vasodilator responses to
substance P
were unchanged by administration of atropine, glibenclamide, or sodium meclofenamate or when airflow to the left lower lung lobe was interrupted by bronchial occlusion. The NO synthesis inhibitor, N omega-nitro-L-argininemethyl ester (L-
NAME
), and the soluble guanylate cyclase inhibitor, methylene blue (MB), selectively inhibited pulmonary vasodilator responses to
substance P
and to acetylcholine. MB or L-
NAME
had no significant effect on pulmonary vasodilator responses to albuterol, lemakalim, or PACAP, whereas MB inhibited and L-
NAME
enhanced vasodilator responses to NO and sodium nitroprusside. The present investigation demonstrates that, when tone is increased experimentally,
substance P
has potent pulmonary vasodilator activity, and responses are not dependent on changes in bronchomotor tone, on the activation of muscarinic receptors or ATP-sensitive K+ channels, or on the release of a dilator prostaglandin but do involve, at least in part, endothelium-derived NO release and soluble guanylate cyclase activation.
...
PMID:Analysis of responses to substance P in the pulmonary vascular bed of the cat. 768 May 35
NOS activity has been recently described in airway epithelial cells. Because these cells are often ciliated we hypothesized that NO modulates airway ciliary beating. CBF was measured in cultured BBECs using video microscopy. L-NMMA, a NOS inhibitor, caused a 40% decrease in CBF following pre-stimulation with isoproterenol (8.5 +/- 0.3 Hz vs 14.6 +/- 0.2 Hz; p < 0.0001) which lasted approximately 60 minutes. Similar attenuation in CBF after isoproterenol pre-treatment was observed with another NOS inhibitor, L-
NAME
. NOS inhibitor-induced CBF slowing was also observed when cells were pre-stimulated with either bradykinin or
substance P
and was completely reversed by L-arginine or SNP but not by D-arginine. These observations demonstrate a novel NO-dependent mechanism that upregulates ciliary motility in response to stimulation.
...
PMID:Modulation of airway epithelial cell ciliary beat frequency by nitric oxide. 768 May 60
The nitric oxide synthase inhibitor, NG-nitro-L-arginine methyl ester (L-
NAME
), administered i.v. (50 mg kg-1) or by iontophoresis, was tested on the responses of spinal dorsal horn neurones in cats anaesthetized with alpha-chloralose and spinally transected at the L1 level. Extracellular, single-unit recordings were obtained from functionally identified dorsal horn cells. All units included in this study were wide dynamic range neurones. L-
NAME
significantly reduced the responses of (i) twelve neurones to noxious thermal stimulation of the receptive field, (ii) nine neurones to noxious pinch, (iii) nine neurones to iontophoretic application of N-methyl-D-aspartate (NMDA) and (iv) ten neurones to iontophoretic application of
substance P
. The inhibition usually lasted for 50-70 min following i.v. administration and for 5-8 min after iontophoretic application of L-
NAME
. The responses of four neurones to iontophoretic application of quisqualate were not affected by L-
NAME
. The results suggest the possible involvement of nitric oxide in the mediation of the spinal effects of NMDA and
substance P
, and in the transmission of thermal and mechanical nociceptive imputs.
...
PMID:L-NAME blocks responses to NMDA, substance P and noxious cutaneous stimuli in cat dorsal horn. 768 58
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