The vascular relaxant effects of guanabenz are not mediated by α2-adrenoceptors in rat aortic rings
- 1 March 1990
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Pharmacy and Pharmacology
- Vol. 42 (3), 209-211
- https://doi.org/10.1111/j.2042-7158.1990.tb05391.x
Abstract
— The present experiments show that the α2‐adrenoceptor agonist guanabenz produced a concentration‐dependent relaxation in 5‐hydroxytryptamine‐ and noradrenaline‐preconstricted rat aortic rings, but not when tone was raised by high potassium in the medium. Similar findings were made for pinacidil. In 5‐hydroxytryptamine‐preconstricted preparations the relaxant effect of guanabenz was not affected by yohimbine, propranolol or by removal of the endothelium. In noradrenaline‐preconstricted rings the relaxant effects of guanabenz and pinacidil were significantly antagonized by tetraethylammonium. The results suggest that guanabenz might act in the muscle tissue by opening potassium channels or antagonism of calcium mobilization from intracellular stores.This publication has 12 references indexed in Scilit:
- Effect of KT-362, a Putative Intracellular Calcium Antagonist, on Norepinephrine-Induced Contractions and Inositol Monophosphate Accumulation in Canine Femoral ArteryJournal of Cardiovascular Pharmacology, 1989
- Effect of Pinacidil on Norepinephrine- and Potassium-Induced Contractions and Membrane Potential in Rat and Human Resistance Vessels and in Rat AortaJournal of Cardiovascular Pharmacology, 1988
- Effect of catecholamines on Na/H exchange in vascular smooth muscle cells.The Journal of cell biology, 1986
- Comparison of the effects of BRL 34915 and verapamil on electrical and mechanical activity in rat portal veinBritish Journal of Pharmacology, 1986
- Interaction of guanidinium and guanidinium derivatives with the Na+/H+ exchange systemEuropean Journal of Biochemistry, 1985
- Characterization of two distinct alpha-adrenoceptor binding sites in smooth muscle cell membranes from rat and bovine aortaNaunyn-Schmiedebergs Archiv für experimentelle Pathologie und Pharmakologie, 1985
- Endothelial mediated inhibition of contraction and increase in cyclic GMP levels evoked by the α‐adrenoceptor agonist B‐HT 920 in rat isolated aortaBritish Journal of Pharmacology, 1984
- Enhanced responsiveness of rat isolated aorta to clonidine after removal of the endothelial cellsBritish Journal of Pharmacology, 1984
- Uneven distribution of postjunctional alpha 1-and alpha 2-like adrenoceptors in canine arterial and venous smooth muscle.Circulation Research, 1981
- Central α-adrenergic systems as targets for hypotensive drugsReviews of physiology, biochemistry and pharmacology, 1978