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. Cultured aortic endothelial cells of the pig respond to the endothelium-derived relaxing factor (EDRF) they release with an increase in cyclic GMP content. This response is inhibited by haemoglobin or by L-NG-monomethyl-arginine (L-NMMA), and has been used to investigate the effects of phorbol esters on EDRF release. 2. Pretreatment with phorbol-12,13-dibutyrate (PDB) but not the inactive 4 alpha-phorbol-12,13,-didecanoate (PDD), inhibited increases in cyclic GMP induced by substance P (10(-8) M) in a time and concentration-dependent manner. PDB did not affect basal cyclic GMP levels. 3. PDB (3 x 10(-7) M), but not PDD (3 x 10(-7) M), also inhibited ATP (10(-5) M)-induced increases in cyclic GMP, but did not affect those induced by bradykinin (10(-7) M). 4. Increases in cyclic GMP induced by low (10(-7) M) but not high (10(-6) M) concentrations of the calcium ionophore A23187 were inhibited by PDB (3 x 10(-7) M). This inhibitory effect was due to enhanced destruction of EDRF by superoxide anions rather than inhibition of EDRF release, as the inhibition was abolished in the presence of superoxide dismutase (SOD, 30 mu ml-1) and catalase (CAT, 100 mu ml-1). 5. SOD and CAT did not affect the inhibitory action of PDB on substance P or ATP-induced increases in cyclic GMP. 6. Increases in endothelial cell cyclic GMP content induced by sodium nitroprusside (10(-5) M) were unaffected by PDB pretreatment. 7. The inhibitory effects of PDB are probably a result of an action of protein kinase C on the steps between receptor occupation and phospholipase C activation.
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PMID:Release of endothelium-derived relaxing factor from pig cultured aortic endothelial cells, as assessed by changes in endothelial cell cyclic GMP content, is inhibited by a phorbol ester. 169 49

Hydrogen peroxide can be released by different cells such as the nerves, the endothelial or phagocytotic white blood cells which can all interact with vascular smooth muscles. We show that hydrogen peroxide hyperpolarizes and relaxes pig coronary artery smooth muscle cells. The possibility that the endothelium derived hyperpolarizing factor released by the endothelium in response to bradykinin and substance P being hydrogen peroxide was tested using catalase, an enzyme which hydrolyses hydrogen peroxide. We find that this particular endothelial hyperpolarizing factor and hydrogen peroxide are two distinct molecules.
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PMID:Hydrogen peroxide: an endogenous smooth muscle cell hyperpolarizing factor. 170 49

The role of oxygen radicals in capsaicin-induced bronchoconstriction was investigated using scavengers of the radicals. A total of 48 guinea pigs weighing 293 +/- 7 g were employed in this study, which consisted of two phases. In phase 1, 35 anesthetized paralyzed animals were divided into five groups: group 1A, control (n = 6); group 1B, chronic dimethylthiourea (DMTU, n = 12); group 1C, acute DMTU (n = 6); group 1D, superoxide dismutase (n = 4); and group 1E, catalase (n = 7). All animals were injected with capsaicin (16 micrograms/kg iv), and changes in respiratory compliance and maximal expiratory flow rate were used as indicators of bronchoconstriction. The capsaicin injection caused a marked airway spasm that was significantly ameliorated by chronic DMTU pretreatment, but no amelioration was noted with the other treatments. An additional study for group 1C was performed using a double dose of DMTU. Again no amelioration was found. In phase 2, 13 animals were divided into two groups: group 2A, substance P (SP, n = 7) and group 2B, chronic DMTU + SP (n = 6). There was no significant difference in SP-induced bronchoconstriction between animals in these two groups. These data suggest that capsaicin-induced airway constriction is modulated by oxygen radicals which may augment mainly on the biosynthesis and/or axonal transport of tachykinins.
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PMID:Oxygen radicals in capsaicin-induced bronchoconstriction. 210 20

We have examined the effect of the trophic protein, nerve growth factor (NGF), on organotypic cultures of fetal rat striatum. Treatment of cultures with NGF for 10-11 days resulted in a 5- to 12-fold increase in the specific activity of the cholinergic enzyme choline acetyltransferase (CAT; EC 2.3.1.6). in a dose-dependent fashion. This effect was not elicited by insulin, ferritin, or cytochrome c, proteins similar in structure or physicochemical properties to NGF. The effect of NGF on CAT activity was specifically blocked by anti-NGF antiserum, whereas treatment with the antiserum alone did not have a significant effect on the enzyme. Immunocytochemical studies of the treated cultures, using a monoclonal antibody directed against CAT, revealed positively stained neurons exhibiting dendritic and axonal processes. NGF did not have an effect on total protein content of the striatal cultures, suggesting a highly specific effect. Moreover, levels of substance P, a peptide localized to other, noncholinergic neurons, were not altered by NGF. Substance P remained unchanged after treatment with NGF for 12 days, whereas CAT activity increased 12-fold in sister cultures. Although the mechanisms of action of NGF on striatal cholinergic interneurons remain to be determined, the marked, specific response of CAT suggests that this well-defined trophic protein may play a critical role in normal brain development.
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PMID:Nerve growth factor promotes cholinergic development in brain striatal cultures. 386 96

Age-related mechanism in exsanguination-induced bronchoconstriction (EIB) was studied in guinea pigs. We used a total of 36 guinea pigs divided into three age categories (immature, adolescent, and mature). Each age category was separated into two groups: control and catalase (CAT). CAT is an antioxidant. Both saline (the control group) and CAT were instilled intratracheally 30 min before exsanguination. The animals were anesthetized, sternotomized and exsanguinated. Maximal expiratory flow (Vmax) was measured both before and 1-30 min after exsanguination. In the control group, exsanguination caused gradual decreases in both total lung capacity (TLC) and Vmax at 50% baseline TLC, and an increase in minimal lung volume, indicating EIB. EIB occurred faster in the immature than in the adolescent and mature guinea pigs, and it was significantly ameliorated by CAT. In 36 additional animals tested before exsanguination, there was no age-related change in either airway neutral endopeptidase (NEP) activity or lung tissue substance P level. Thirty minutes after exsanguination in the control groups, airway NEP activity decreased significantly in all age categories, while lung tissue substance P level increased significantly only in the immature category. CAT prevented most of these NEP and substance P changes. These data suggest that exsanguination increases production of oxygen radicals, which inactivate NEP and enhance breakdown of substance P precursor; the increased tachykinin levels induce EIB. Furthermore, our data indicate that this chain reaction is age-dependent, with a faster and more severe reaction in immature guinea pigs.
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PMID:Age-dependent mechanism in guinea pig bronchoconstriction induced by exsanguination. 753 41

This study investigated the relationship between oxygen radicals and exsanguination-induced bronchoconstriction using antioxidant in guinea pigs. To accomplish this, two phases of studies were carried out. In phase 1, 34 guinea pigs weighing 342 +/- 11 g were divided into five groups: control (n = 7); acute dimethylthiourea (DMTU, n = 7); chronic DMTU (n = 8); superoxide dismutase (SOD, n = 6); and catalase (n = 6). Animals in the control group were not treated. DMTU, SOD, and catalase were employed for the scavenging of hydroxyl radical, superoxide anion, and hydrogen peroxide, respectively. Ten additional guinea pigs weighing 293 +/- 6 g were divided into two groups in phase 2: sham (n = 6) and chronic apocynin (n = 4). Animals in the sham group received injections of the vehicle, whereas apocynin was used to suppress the production of superoxide anion. All animals were anesthetized, sternotomized, and artificially ventilated. Before (baseline) as well as at fixed intervals 5-30 minutes following the exsanguination, the maximal expiratory flow maneuver was performed and the dynamic compliance (Cdyn) was obtained. Decreases in the maximal expiratory flow at 50% baseline vital capacity and Cdyn were used as indicators of bronchoconstriction. Exsanguination in the control and sham groups caused a gradual increase in airway constriction with time that was significantly ameliorated by chronic DMTU and chronic apocynin pretreatments but was not affected by other acute treatments. These results indicate that chronic treatment with antioxidants ameliorates exsanguination-induced, tachykinin-mediated airway constriction.
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PMID:Oxygen radicals in exsanguination-induced bronchoconstriction of guinea pigs. 793 52

Coronary artery contractility is well known to be modulated by oxygen partial pressure. Both smooth muscle and the endothelium contribute to coronary artery oxygen sensitivity. Mechanisms underlying endothelium-dependent effects of oxygen include the sensitivity of the nitric oxide/endothelium-derived relaxing factor (EDRF), hydrogen peroxide, and eicosanoid pathways. In the present study, we characterize a novel endothelium-dependent component of porcine coronary artery oxygen sensitivity that is independent of these known pathways. Porcine coronary arteries were stimulated with either KCl or U46619. Hypoxia elicited a transient increase in force that was much greater in endothelium-intact arteries. This effect was abolished by nitric oxide/EDRF pathway inhibitors NG-monomethyl-L-arginine and N-nitro-L-arginine. In the steady state, hypoxia reduced isometric force to a similar degree in both intact and denuded arteries. Reoxygenation elicited a rapid and transient relaxation only in intact arteries. In contrast, this endothelium-dependent relaxation was not inhibited by nitric oxide/EDRF pathway inhibitors nor inhibitors of other potential oxygen-sensitive pathways, such as indomethacin, aminotriazole, superoxide dismutase, catalase, propranolol, or ouabain. The reoxygenation relaxation was, however, sensitive to very low levels of oxygen and was inhibited by cyanide and rotenone, suggesting an involvement of mitochondrial metabolism. Interestingly, the relaxation response to reoxygenation, similar to that for substance P, could be restored in denuded arteries by coupling with an endothelium-intact donor artery. This "sandwich" experiment suggests that the endothelium dependence is mediated by a transmissible factor. Our results indicate that a novel class of endothelium-dependent factors may contribute to coronary artery responses to changes in oxygen partial pressure.
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PMID:Reoxygenation-induced relaxation of coronary arteries. A novel endothelium-dependent mechanism. 815 34

In the airways and lungs, activated afferent C-fibers release tachykinins, which induce noncholinergic bronchoconstriction. We have, for several years, focused our research on the role of axon reflex and oxygen radicals in noncholinergic airway constriction in guinea pigs. In this species, the noncholinergic bronchial constriction is not affected by administration of a ganglionic blocking agent, chlorisondamine, indicating that only the afferent C-fiber, not a complete reflex arc, is required for this constriction. Accordingly, we investigated the role of axon reflex by using tetrodotoxin (TTX) and bupivacaine to block impulse conduction in the axon. For the role of oxygen radicals, superoxide dismutase (SOD), catalase (CAT), and dimethylthiourea (DMTU) were employed to scavenge superoxide anion, hydrogen peroxide, and hydroxyl radical, respectively. We used capsaicin, resiniferatoxin (RTX), or hyperventilation to activate afferent C-fibers which, in turn, release tachykinins and lead to noncholinergic airway constriction. The constriction was quantified by measuring the maximal expiratory flow rate (Vmax) and dynamic compliance (Crs). Both capsaicin and RTX caused an immediate decrease in Vmax and Crs, indicating severe bronchoconstriction. This constriction decreased gradually with time. Tachykinin depletion abolished neurotoxin-induced airway constriction, suggesting that tachykinins mediate the constriction. Both TTX and bupivacaine significantly attenuated the constriction at 15-20 min after neurotoxin administration. Therefore, these data suggest that the axon reflex plays an important role in noncholinergic bronchial constriction. In other studies, capsaicin- or hyperventilation-induced bronchoconstriction was abolished by tachykinin depletion, as well as significantly ameliorated by the administration of antioxidants. These data indicate that oxygen radicals modulate the tachykinin-mediated noncholinergic airway constriction.
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PMID:Noncholinergic airway constriction: role of axon reflex and oxygen radicals. 819 89

Endogenous nitric oxide (NO, endothelium-derived relaxing factor) was stimulatory for histamine- and suppressive for serotonin-induced paw edema of mice. This action was mediated by guanosine 3',5'-cyclic monophosphate production. Local injection of superoxide dismutase (SOD), catalase, NG-monomethyl-L-arginine (L-NMMA), methylene blue and Desferal (iron chelator) mixed with mediator suppressed histamine-induced edema at doses between 0.1 and 100 micrograms/kg and showed no or little stimulatory effect at higher doses. L-arginine reversed the effect of L-NMMA. Serotonin edema was enhanced by a high dose of these drugs. Their effect became suppressive as the histamine ratio was increased in edema induced by a histamine-serotonin mixture. This suggested that serotonin-induced vascular permeability decreased with a greater production of either O2- or NO. Cimetidine (H2-antagonist) was not effective in histamine edema of normal mice, but became suppressive (ED50 = 70 micrograms/kg) when 10 mg/kg L-NMMA was coinjected. SOD and methylene blue also rendered this edema sensitive to cimetidine. A simultaneous decrease in sensitivity to mepyramine (H1-antagonist) indicated that NO and oxyradicals kept H1-receptors activated. L-NMMA had no effect on bradykinin edema, but suppressed thrombin-, acetylcholine-, platelet-activating factor-, substance P- and FeCl3-induced paw edemata. Nitroprusside (NO donator) suppressed serotonin edema. N-Acetylcysteine and cytochrome c, but not ascorbate and hydroxyl radical scavengers suppressed histamine edema.
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PMID:Opposite effect of superoxide dismutase, L-arginine analogues, methylene blue and desferal: suppression of histamine-induced and stimulation of serotonin-induced paw edema in mice. 835 90

The role of oxygen radicals in isocapnic hyperpnea-induced bronchoconstriction (HIB) of guinea pigs was investigated using scavengers of the radicals. In series 1, 50 young guinea pigs were randomly divided into seven groups: control 1, control 2, chlorisondamine, tetrodotoxin (TTX), acute dimethylthiourea (DMTU), tachykinin depletion, and 5% CO2 in air. Animals of the control 2 group received vehicle (saline) infusion while those of the control 1 group did not. Chlorisondamine was used to block ganglionic transmission, TTX to interrupt nerve conduction, DMTU to scavenge hydroxyl radicals, and chronic capsaicin pretreatment to deplete tachykinins. The animals in the last group were ventilated with dry 5% CO2 in air during hyperpnea. In series 2, 13 additional animals were used to test the effects of intratracheal administration of superoxide dismutase and catalase (SOD + CAT) on HIB. Each animal was anesthetized with pentobarbital sodium, cannulated with a tracheal cannula and venous catheter, paralyzed with gallamine triethiodide, and mechanically ventilated. During the baseline period, each animal was ventilated normally with humidified air. Then it was hyperventilated 15 min with a dry gas mixture of 95% O2-5% CO2, except animals in the last group of series 1. Subsequently, all animals returned to normal ventilation with humidified air for 45 min (recovery period). The maximal expiratory flow and dynamic compliance were obtained periodically during the recovery period. The isocapnic hyperpnea using 95% O2-5% CO2, but not 5% CO2 in air, caused bronchoconstriction that was significantly blocked by acute DMTU, acute SOD + CAT, and tachykinin depletion. In an additional group of six animals, acute DMTU did not significantly alter acetylcholine-induced airway constriction.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Oxygen radicals in bronchoconstriction of guinea pigs elicited by isocapnic hyperpnea. 845 78


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