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Query: UNIPROT:P20366 (
substance P
)
21,176
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Antropyloroduodenal motility was recorded in seven anesthetized dogs to assess the role of nitric oxide and L-arginine metabolites in nonadrenergic noncholinergic (NANC) mediation of pyloric relaxation. Pyloric activity induced by duodenal field stimulation was inhibited by antral field stimulation and electrical vagal stimulation. Intra-arterial NG-L-arginine-methyl-ester (L-NAME) reduced the inhibition from antral or vagal stimulation (P less than 0.05). Intravenous infusion of L-NAME also blocked the inhibitory effect of vagal and antral stimulation but left the tetrodotoxin-insensitive action of intra-arterial vasoactive intestinal peptide (VIP) and sodium nitroprusside unchanged. L-Arginine reversed the effect of L-NAME whereas D-arginine did not. L-NAME enhanced pyloric contractions to intra-arterial acetylcholine. The NANC inhibition of the
substance P
-stimulated pyloric response in vitro was blocked by L-NAME and reversed by addition of L-arginine.
Sodium nitroprusside
was effective as a relaxant in vitro but VIP was not. These data suggest that metabolites of L-arginine mediate neural inhibition of canine pyloric motor activity.
...
PMID:Nitric oxide as a putative nonadrenergic noncholinergic inhibitory transmitter in the canine pylorus in vivo. 134 7
The results of behavioral studies suggest that nitric oxide (NO) participates in certain spinal mechanisms that contribute to hyperalgesia. Additionally, previous studies indicate that the release of immunoreactive calcitonin gene-related peptide (iCGRP) and
substance P
(iSP) is increased in the dorsal horn of the spinal cord during hyperalgesia. Therefore, the aim of this study was to determine whether NO acts to enhance peptide release in the dorsal horn of rats using an in vitro superfusion technique.
Sodium nitroprusside
(SNP) was used as an NO donor. The results of this study indicate that SNP caused a dose-related, calcium-dependent increase in the release of iCGRP and iSP from dorsal horn slices of the rat spinal cord. Furthermore, pretreatment with SNP reduced the ability of capsaicin to evoke the release of either peptide, suggesting that a target for SNP exists on certain capsaicin-sensitive primary afferent terminals. In addition to increasing peptide release, SNP also caused a significant five to sixfold increase in the levels of immunoreactive guanosine 3',5'-monophosphate (i-cGMP) in the dorsal horn. This SNP-evoked increase was significantly decreased by the guanylate cyclase inhibitor methylene blue in a dose-dependent manner. In addition, the release of iCGRP was also significantly reduced in the presence of methylene blue, although the relationship between peptide release and i-cGMP production remains unclear.
Sodium nitroprusside
-evoked peptide release was significantly reduced in the presence of hemoglobin (an oxide radical scavenger), suggesting that the drug effect was due to the generation of NO. However, the release of iCGRP and iSP was also evoked by sodium ferricyanide (the coproduct of SNP) and by 7-d-old, photoinactivated SNP.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Sodium nitroprusside evokes the release of immunoreactive calcitonin gene-related peptide and substance P from dorsal horn slices via nitric oxide-dependent and nitric oxide-independent mechanisms. 751 95
Recent studies demonstrate that nitric oxide and cyclic guanosine 3',5'-monophosphate may mediate hyperalgesia induced by N-methyl-D-aspartate at the level of the spinal cord. One possible mechanism for this action is that nitric oxide increases transmitter release from the primary afferent nociceptors that synapse in the dorsal horn of the spinal cord. To address this possibility, we investigated whether various nitric oxide donors and cyclic guanosine 3',5'-monophosphate could alter the release of
substance P
and calcitonin gene-related peptide from rat sensory neurons in culture.
Sodium nitroprusside
(100 nM to 100 microM) had little effect on basal release of either peptide, but it significantly increased the release of
substance P
and calcitonin gene-related peptide induced by 50 nM capsaicin. In contrast, sodium nitroprusside did not alter release evoked by 100 nM bradykinin or 30 mM KCl. Two other nitric oxide-donating compounds, S-nitroso-N-acetylpenicillamine and 3-morpholinosydnonimine did not enhance resting or capsaicin-evoked peptide release, although they induced a marked elevation in the intracellular cyclic guanosine 3',5'-monophosphate levels. Pretreating the cultures with 8-bromo-cyclic guanosine 3',5'-monophosphate, (0.5 or 0.1 mM for 30 or 60 min) did not result in the enhancement of capsaicin-induced release from sensory neurons. Moreover, pretreating the cells with the nitric oxide synthase inhibitor, NG-nitro-L-arginine (100 microM), abolished the rise in cyclic guanosine 3',5'-monophosphate induced by capsaicin without altering capsaicin-stimulated release of either peptide.(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Nitric oxide and cyclic guanosine 3',5'-monophosphate do not alter neuropeptide release from rat sensory neurons grown in culture. 753 4
The modulatory role of endogenous nitric oxide (NO) on pulmonary edema induced by acetylcholine (ACh), capsaicin,
substance P
(SP) and 5-hydroxytryptamine (5-HT) was investigated by using an inhibitor of NO synthase, N-omega-nitro-L-arginine (L-NNA). The effects of endogenous NO on the hemodynamic response to ACh, 5-HT and SP were also investigated. The capillary filtration coefficient (Kf,c), the total pressure gradient (delta Pt) and its four components [arterial (delta Pa), pre- (delta Pa') and post-capillary (delta Pv'), and venous gradient (delta Pv)] were evaluated on isolated, ventilated, perfused rabbit lungs. ACh (10(-8) to 10(-4) M) and SP (10(-10) to 10(-6) M) induced a concentration-dependent increase in the Kf,c. Capsaicin (10(-4) M) and 5-HT (10(-4) M) also increased this parameter. L-NNA (10(-4) M) completely inhibited the effects of ACh and capsaicin on the Kf,c, without preventing the effects of SP and 5-HT. ACh induced a concentration-dependent vasoconstriction in the precapillary segment. Pretreatment with L-NNA enhanced this increase in delta Pa' but also increased delta Pv' and delta Pv. 5-HT increased delta Pt and delta Pa proportionally to the concentration. This effect was enhanced by L-NNA, which also increased delta Pa'. SP had no significant hemodynamic effect. Pretreatment with L-NNA did not modify the response to SP.
Sodium nitroprusside
(10(-5) M) induced a left shift of the concentration-response curve to ACh on the Kf,c, although it did not change the response to SP.
Sodium nitroprusside
also inhibited the hemodynamic effect of ACh. It was concluded that endogenous NO is involved in ACh-and capsaicin-induced edema via a prejunctional stimulatory effect on the C-fibers. Endogenous NO can also modulate ACh- and 5-HT-induced vasoconstriction by exerting a vasodilator action on the whole pulmonary vascular bed.
...
PMID:Endogenous nitric oxide modulates acetylcholine-induced edema and vasoconstriction in isolated perfused rabbit lungs. 754 68
In order to determine whether nitric oxide (NO) acts directly upon nerve terminals to regulate the synaptic transmission at the level of spinal cord, effects of NO-donors on release of
substance P
(SP) and glutamic acid (Glu) were investigated by superfusion of synaptosomes prepared from the rat spinal cord. Basal levels of endogenous SP and Glu release were 5.99 +/- 2.50 fmol/min/mg of protein and 26.2 +/- 4.8 pmol/min/mg of protein, respectively. Exposure to a depolarizing concentration of KCI evoked 2.7- and 3.8-fold increases in SP and Glu release in a calcium-dependent manner, respectively.
Sodium nitroprusside
(NP) caused a reduction in the depolarization-evoked overflow of SP in a concentration-dependent manner without affecting its basal release, although it failed to affect either basal or evoked release of Glu. The reduction in SP overflow was also observed by the perfusion with S-nitroso-N-acetyl-penicillamine or membrane-permeable cyclic GMP, but not with cyclic AMP. NP caused the concentration-dependent increases in cyclic GMP levels in synaptosomes. Together with reports that excitatory amino acids stimulate NO synthase and release NO in the spinal cord, these data suggest that there may be an interaction between nerve terminals containing Glu and SP, and that NO may directly participate in the regulation of synaptic transmission in SP-containing nerve terminals, which may be mediated through the activation of guanylate cyclase and the increase in cyclic GMP levels.
...
PMID:Nitric oxide regulates substance P release from rat spinal cord synaptosomes. 759 89
Sodium nitroprusside
(NaNP) was used as a donor of nitric oxide (NO) to investigate actions of NO on electrical and synaptic behavior of single myenteric neurons in guinea pig small intestine. NaNP (10 microM-1 mM) did not affect resting membrane properties of the neurons, except for an occasional decrease in input resistance and hyperpolarization attributable to suppression of excitatory transmitter release. NaNP did not alter fast nicotinic neurotransmission but suppressed noncholinergic slow excitatory postsynaptic potentials (slow EPSPs) in a concentration-dependent manner. Pretreatment with either methylene blue or oxyhemoglobin reduced the inhibitory action of NaNP on the slow EPSPs. Slow EPSP-like responses to microejected
substance P
or 5-hydroxytryptamine were unaffected by NaNP. The nitric oxide synthase inhibitor, N omega-nitro-L-arginine methyl ester, did not affect resting membrane excitability or excitatory synaptic events in any of the myenteric neurons. The results suggest that NO may not be released extensively as a neurotransmitter at synapses within the myenteric plexus. If myenteric neurons are exposed to NO released from nonneural sources, then the principal action is expected to be presynaptic inhibition of slow synaptic excitation.
...
PMID:Actions of nitric oxide-generating sodium nitroprusside in myenteric plexus of guinea pig small intestine. 823 18
1. Inhibition of nitric oxide synthase by NG-nitro-L-arginine (L-NNA) reduced the neurogenic relaxation of precontracted taenia coli only in the absence of atropine. The membrane hyperpolarization associated with the neurogenic relaxation was also reduced by inhibition of NOS only when atropine was absent. 2. The membrane hyperpolarization associated with the neurogenic relaxation of the taenia coli was inhibited by oxyhaemoglobin only in the absence of atropine. In the presence of atropine, oxyhaemoglobin did not reduce the i.j.p. or nerve evoked relaxation. 3. Inhibition of NOS by L-NNA did not affect the overflow of [3H]-ACh in response to electrical field stimulation (EFS), suggesting that, under the conditions of our experiments, endogenous NO did not modulate release of ACh.
Sodium nitroprusside
also had no effect on the neurogenic overflow of [3H]-ACh; however, noradrenaline significantly reduced [3H]-ACh overflow. 4. In summary, the postjunctional effects of neurally-released NO are not apparent in guinea-pig taenia coli when atropine is present. This implies muscarinic regulation of NO release or muscarinic regulation of another excitatory substance, such as
tachykinin
(s), that, when blocked, masks the postjunctional effects of NO. These data, together with previous studies, suggest a possible regulatory role for NO in enteric neurotransmission that may be more prominent in some species or tissues than others.
...
PMID:Hyperpolarization and inhibition of contraction mediated by nitric oxide released from enteric inhibitory neurones in guinea-pig taenia coli. 873 75
Nitric oxide (NO) mediates neurogenic relaxations of gastrointestinal (GI) smooth muscle. NO synthase (NOS) inhibitors also alter neurogenic contractions, suggesting NO modulates excitatory neurotransmitter release. In circular muscle-myenteric plexus preparations, guanethidine and either scopolamine or CP-96,345, a neurokinin-1 (NK1) receptor antagonist, were used to isolate nonadrenergic, noncholinergic (NANC) or cholinergic contractions, respectively. NOS inhibitors and hemoglobin potentiated neurogenic NANC but not cholinergic contractions and did not affect NK1 receptor agonist [
substance P
methyl ester (SPME)]-induced contractions.
Sodium nitroprusside
(SNP), a NO donor, attenuated NANC and cholinergic neurogenic contractions, but cholinergic contractions were less sensitive to SNP. SNP partially attenuated SPME-induced contractions, and apamin reduced inhibition of NANC contractions by SNP. Bethanechol responses were not affected by SNP. These data indicate NANC but not cholinergic contractions are inhibited by endogenous NO, suggesting differential regulation of release of tachykinins and acetylcholine from enteric nerves. NK1 receptor-but not muscarinic receptor-activated postjunctional pathways are also inhibited by NO. Therefore, prejunctional and postjunctional modulation of NANC contractions are mechanisms for inhibition of GI motility by endogenous NO.
...
PMID:Endogenous NO inhibits NANC but not cholinergic neurotransmission to circular muscle of guinea pig ileum. 894 6
Dimalonic acid C60 (10(-5) M), a new fullerene derivative, produced an augmentation of phenylephrine-induced tone and reduced both the acetylcholine-induced maximum relaxation and the amplitude of
substance P
(10(-8) M)-induced relaxation in endothelium-containing thoracic aorta of rabbit; the acetylcholine- and
substance P
-induced relaxation was restored in the presence of superoxide dismutase (250 U/ml). Dimalonic acid C60 (10(-5) M) did not influence the phenylephrine-induced contractile response in the absence of endothelium, but the acetylcholine-induced relaxation was eliminated by removal of the endothelium. Superoxide anion generation, using hypoxanthine (1 mM)/xanthine oxidase (16 mU/ml), reduced the acetylcholine-induced relaxation and produced an augmentation of phenylephrine-induced tone in endothelium-containing strips; these effects were negated by the addition of superoxide dismutase (250 U/ml). A nitric oxide-generating agent, S-nitroso-N-acetylpenicillamine, caused relaxation of aorta without endothelium in a concentration-dependent manner, and the concentration-response curve was shifted to the right in the presence of dimalonic acid C60. This inhibitory effect of dimalonic acid C60 was also masked in the presence of superoxide dismutase.
Sodium nitroprusside
-induced relaxation was not affected by either dimalonic acid C60 or superoxide dismutase. These observations suggest that dimalonic acid C60 inhibits endothelium (nitric oxide)-dependent agonist-induced relaxation through the production of superoxide.
...
PMID:Inhibitory effects of a fullerene derivative, dimalonic acid C60, on nitric oxide-induced relaxation of rabbit aorta. 920 May 57
1. The pattern of responses of longitudinally oriented guinea pig ileum organ bath preparations was studied during short- (1-5 sec) or long-lasting (20 sec) electrical field stimulation (EFS, 0.8 msec, 40 V, 1-20 Hz). 2. In the presence of phentolamine (5 microM), propranolol (5 microM), and atropine (3 microM), the EFS elicited nonadrenergic, noncholinergic (NANC), tetrodotoxin (0.3 microM)-sensitive responses. 3. The 1-sec EFS evoked relaxation. The response to 5-sec EFS consisted of relaxation followed by twitch, whereas relaxation, twitch and tonic contraction characterized the NANC response to 20-sec EFS. The maximum relaxation was observed at 10-Hz short- or long-lasting EFS. 4. Both N-G-nitro-L-arginine (L-NNA, 0.1-0.5 mM) and apamin (1-5 microM) concentration dependently inhibited the relaxation of the NANC response to 10-Hz 20-sec EFS. During L-NNA treatment, the twitch and the tonic contractions were increased. The inhibitory effect of L-NNA was reversed by L-arginine (0.1-0.5 mM) but not by D-arginine.
Sodium nitroprusside
(1-10 microM) was without effect. 5. AP 13.2 ACOH (0.1 microM), a blocker of
Substance P
receptors, inhibited the twitch and the tonic contractions. The contractions were decreased after desensitization of purinoceptors by ATP and in the presence of the GABA(A) receptor antagonist bicuculline (30 microM). 6. Depending on the EFS duration, a subsequent occurrence of relaxation and contractions characterized the NANC responses. It seems that relaxation is mediated by nitric oxide whereas
Substance P
and ATP are involved in the maintenance of the twitch and the tonic contractions. Nitric oxide appears to exert an inhibitory effect on the excitatory transmitters, whereas purinergic mechanism(s) could modulate the nitric oxide-dependent relaxation.
...
PMID:Pattern of nonadrenergic, noncholinergic responses during short- or long-lasting electrical stimulation in guinea-pig ileum. 925 5
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