The Experts below are selected from a list of 93 Experts worldwide ranked by ideXlab platform
T M Cocks - One of the best experts on this subject based on the ideXlab platform.
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effects of u46619 on contractions to 5 ht sumatriptan and Methysergide in canine coronary artery and saphenous vein in vitro
British Journal of Pharmacology, 1995Co-Authors: Barbara Kathryn Kemp, T M CocksAbstract:: 1. The aim of this study was to investigate the mechanism of enhanced reactivity to 5'-hydroxytryptamine (5-HT) and sumatriptan previously observed in human isolated coronary arteries when active force was raised with the thromboxane A2-mimetic, U46619. 2. Ring segments of dog isolated coronary artery and saphenous vein were suspended in organ baths and cumulative concentration-contraction curves to 5-HT, sumatriptan and Methysergide were constructed in the absence and presence of low concentrations of U46619. 3. In both endothelium-intact and endothelium-denuded rings of coronary artery, precontraction with U46619 to low (< 10% Fmax; the contraction to a maximum depolarizing 125 mM KCl Krebs solution; KPSS) levels of active force had no effect on either the maximum contraction or sensitivity (pEC50) to 5-HT, sumatriptan and Methysergide. 4. Ketanserin (1 microM) had no effect on contractions to sumatriptan and Methysergide in endothelium-denuded coronary artery rings, but reduced the maximum contraction to 5-HT by approximately 90% to a value (5% Fmax) similar to that for sumatriptan and methylsergide. Under these conditions, U46619 precontraction had no effect on either pEC50 or maximum for 5-HT, sumatriptan or Methysergide. 5. In rings of saphenous vein with endothelium and treated with ketanserin (1 microM), 5-HT and sumatriptan caused equal maximum responses of 65% Fmax which were approximately double that of Methysergide (32% Fmax). The maximum responses and sensitivity to 5-HT, sumatriptan, Methysergide and noradrenaline were unaffected by precontraction with U46619. 6. Pretreatment of the saphenous vein with sodium nitroprusside (SNP; 10 microM) caused a small sustained relaxation and significantly depressed the maximal contraction to 5-HT without affecting sensitivity and abolished the contraction curve to sumatriptan and Methysergide. When the relaxation response to SNP was reversed with U46619 (1-4 nM), the contraction curves to 5-HT, sumatriptan and Methysergide were similar to those obtained prior to relaxation with SNP. In contrast, the same treatment with SNP had little affect on the contraction curve to noradrenaline.7 In conclusion, the pattern of U46619-enhanced reactivity of 5-HT, sumatriptan and Methysergide in SNP-treated dog saphenous vein, highlights the importance of functional antagonism when assessing reactivity to contractile agonists in isolated blood vessels.
Arumugam Manoharan - One of the best experts on this subject based on the ideXlab platform.
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Methysergide induced retroperitoneal fibrosis successful outcome and two new laboratory features
Mayo Clinic Proceedings, 1997Co-Authors: Joseph Bucci, Arumugam ManoharanAbstract:A 25-year-old woman sought medical attention because of iliocaval manifestations of retroperitoneal fibrosis while she was taking Methysergide. Laboratory studies yielded substantially increased serum procollagen III levels and anticardiolipin antibodies accompanied with anti-β 2 glycoprotein I, findings not previously described with this disorder. Clinical and laboratory manifestations resolved after cessation of Methysergide therapy.
Paavo Riekkinen - One of the best experts on this subject based on the ideXlab platform.
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Effects of combined Methysergide and mecamylamine/scopolamine treatment on spatial navigation.
Brain Research, 1992Co-Authors: Minna Riekkinen, Paavo Riekkinen, J SirvioAbstract:In the present study, we investigated the effects of a 5-HT2 receptor antagonist, Methysergide (2.5, 7.5 and 20 mg/kg), on spatial learning in saline, mecamylamine (10 mg/kg) and scopolamine (0.8 mg/kg) treated rats. Methysergide had no effect on water-maze (WM) spatial learning in rats subjected to saline or mecamylamine pretreatments. However, scopolamine-induced WM learning deficit was augmented by Methysergide at doses of 7.5 and 20 mg/kg. These results further suggest (A) that cholinergic and serotonergic systems may interact in the regulation of spatial learning, and (B) that the cholinergic component of this interaction with serotonin2 receptors is mediated by muscarinic receptors, but not by nicotinic receptors.
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effects of combined Methysergide and mecamylamine scopolamine treatment on spatial navigation
Brain Research, 1992Co-Authors: Minna Riekkinen, Paavo Riekkinen, J SirvioAbstract:Abstract In the present study, we investigated the effects of a 5-HT 2 receptor antagonist, Methysergide (2.5, 7.5 and 20 mg/kg), on spatial learning in saline, mecamylamine (10 mg/kg) and scopolamine (0.8 mg/kg) treated rats. Methysergide had no effect on water-maze (WM) spatial learning in rats subjected to saline or mecamylamine pretreatments. However, scopolamine-induced WM learning deficit was augmented by Methysergide at doses of 7.5 and 20 mg/kg. These results further suggest (A) that cholinergic and serotonergic systems may interact in the regulation of spatial learning, and (B) that the cholinergic component of this interaction with serotonin 2 receptors is mediated by muscarinic receptors, but not by nicotinic receptors.
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non reversal of scopolamine or age related eeg changes by ondansetron Methysergide or alaproclate
Psychopharmacology, 1991Co-Authors: Paavo Riekkinen, Jouni SirvioAbstract:The present studies investigates the effects of a 5HT3-antagonist (ondansetron: 0.01, 0.1, 1, 10 µg), a 5HT2-antagonist (Methysergide: 2, 10, 20 mg/kg) and a serotonin uptake inhibitor (alaproclate: 2, 10, 20 mg/kg) on the neocortical electrical activity of young scopolamine-treated and aged rats. The scopolamine (0.2 and 0.8 mg/kg)-induced increase in EEG spectral components was not reversed by ondansetron, Methysergide or alaproclate. The scopolamine (0.8 mg/kg)-induced EEG amplitude increase reversing potency of a subthreshold dose of the muscarinic agonist pilocarpine (2 mg/kg) was not potentiated by ondansetron, Methysergide or alaproclate. A higher dose of pilocarpine (10 mg/kg) reversed scopolamine-induced EEG slowing. Age-related increase in high voltage spindles (HVS) was not alleviated by either ondansetron, Methysergide or alaproclate. The HVS activity stabilizing effect of pilocarpine (2 mg/kg) was not enhanced by ondansetron, Methysergide or alaproclate. These results suggest that the serotonergic agents investigated could not alleviate cortical cholinergic activation deficit and once again implicate the role of cholinergic system in both the neocortical electrical activation and age-related cortical electrical arousal deficit.
J Sirvio - One of the best experts on this subject based on the ideXlab platform.
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effects of combined Methysergide and mecamylamine scopolamine treatment on spatial navigation
Brain Research, 1992Co-Authors: Minna Riekkinen, Paavo Riekkinen, J SirvioAbstract:Abstract In the present study, we investigated the effects of a 5-HT 2 receptor antagonist, Methysergide (2.5, 7.5 and 20 mg/kg), on spatial learning in saline, mecamylamine (10 mg/kg) and scopolamine (0.8 mg/kg) treated rats. Methysergide had no effect on water-maze (WM) spatial learning in rats subjected to saline or mecamylamine pretreatments. However, scopolamine-induced WM learning deficit was augmented by Methysergide at doses of 7.5 and 20 mg/kg. These results further suggest (A) that cholinergic and serotonergic systems may interact in the regulation of spatial learning, and (B) that the cholinergic component of this interaction with serotonin 2 receptors is mediated by muscarinic receptors, but not by nicotinic receptors.
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Effects of combined Methysergide and mecamylamine/scopolamine treatment on spatial navigation.
Brain Research, 1992Co-Authors: Minna Riekkinen, Paavo Riekkinen, J SirvioAbstract:In the present study, we investigated the effects of a 5-HT2 receptor antagonist, Methysergide (2.5, 7.5 and 20 mg/kg), on spatial learning in saline, mecamylamine (10 mg/kg) and scopolamine (0.8 mg/kg) treated rats. Methysergide had no effect on water-maze (WM) spatial learning in rats subjected to saline or mecamylamine pretreatments. However, scopolamine-induced WM learning deficit was augmented by Methysergide at doses of 7.5 and 20 mg/kg. These results further suggest (A) that cholinergic and serotonergic systems may interact in the regulation of spatial learning, and (B) that the cholinergic component of this interaction with serotonin2 receptors is mediated by muscarinic receptors, but not by nicotinic receptors.
Barbara Kathryn Kemp - One of the best experts on this subject based on the ideXlab platform.
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effects of u46619 on contractions to 5 ht sumatriptan and Methysergide in canine coronary artery and saphenous vein in vitro
British Journal of Pharmacology, 1995Co-Authors: Barbara Kathryn Kemp, T M CocksAbstract:: 1. The aim of this study was to investigate the mechanism of enhanced reactivity to 5'-hydroxytryptamine (5-HT) and sumatriptan previously observed in human isolated coronary arteries when active force was raised with the thromboxane A2-mimetic, U46619. 2. Ring segments of dog isolated coronary artery and saphenous vein were suspended in organ baths and cumulative concentration-contraction curves to 5-HT, sumatriptan and Methysergide were constructed in the absence and presence of low concentrations of U46619. 3. In both endothelium-intact and endothelium-denuded rings of coronary artery, precontraction with U46619 to low (< 10% Fmax; the contraction to a maximum depolarizing 125 mM KCl Krebs solution; KPSS) levels of active force had no effect on either the maximum contraction or sensitivity (pEC50) to 5-HT, sumatriptan and Methysergide. 4. Ketanserin (1 microM) had no effect on contractions to sumatriptan and Methysergide in endothelium-denuded coronary artery rings, but reduced the maximum contraction to 5-HT by approximately 90% to a value (5% Fmax) similar to that for sumatriptan and methylsergide. Under these conditions, U46619 precontraction had no effect on either pEC50 or maximum for 5-HT, sumatriptan or Methysergide. 5. In rings of saphenous vein with endothelium and treated with ketanserin (1 microM), 5-HT and sumatriptan caused equal maximum responses of 65% Fmax which were approximately double that of Methysergide (32% Fmax). The maximum responses and sensitivity to 5-HT, sumatriptan, Methysergide and noradrenaline were unaffected by precontraction with U46619. 6. Pretreatment of the saphenous vein with sodium nitroprusside (SNP; 10 microM) caused a small sustained relaxation and significantly depressed the maximal contraction to 5-HT without affecting sensitivity and abolished the contraction curve to sumatriptan and Methysergide. When the relaxation response to SNP was reversed with U46619 (1-4 nM), the contraction curves to 5-HT, sumatriptan and Methysergide were similar to those obtained prior to relaxation with SNP. In contrast, the same treatment with SNP had little affect on the contraction curve to noradrenaline.7 In conclusion, the pattern of U46619-enhanced reactivity of 5-HT, sumatriptan and Methysergide in SNP-treated dog saphenous vein, highlights the importance of functional antagonism when assessing reactivity to contractile agonists in isolated blood vessels.
