Enhanced relaxation to the rho-kinase inhibitor Y-27632 in mesenteric arteries from mineralocorticoid hypertensive rats.
Increased vasoconstriction is characteristic of hypertension. In this study, we tested the hypothesis that changes in vascular responses during mineralocorticoid hypertension may be due to increased activation of the Rho/Rho-kinase pathway. To test this, relaxation responses to the Rho-kinase inhibitor Y-27632 were determined by measuring isometric force in deendothelialized mesenteric arteries from mineralocorticoid-hypertensive rats and sham-operated controls. Following agonist-induced contraction by serotonin (5-HT, 5-hydroxytryptamine), arteries from hypertensive rats demonstrated a greater relaxation to the Rho-kinase inhibitor Y-27632 (65 +/- 5% vs. 28 +/- 10%). Treatment with an EC50 concentration of Y-27632 following a KCl-induced contraction caused minimal relaxation of arteries in both groups of animals. These findings suggest that augmented Rho-kinase activity in the vasculature of mineralocorticoid hypertensive rats may contribute to the enhanced vascular reactivity of agonist-mediated stimuli characteristic of this model of hypertension.
Weber
D S
DS
Department of Physiology, Medical College of Georgia, 120 Fifteenth Street, Augusta, GA 30912-3000, USA. dweber@psych.mcg.edu
Webb
R C
RC
D000577:Amides / Q000494:pharmacology*; D000818:Animals; D003900:Desoxycorticosterone; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000502:physiology; D011189:Potassium Chloride / Q000494:pharmacology; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects*; D054460:rho-Associated Kinases
D000577:Amides; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D011725:Pyridines; C108830:Y 27632; D012701:Serotonin; D003900:Desoxycorticosterone; D011189:Potassium Chloride; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases