Verdict in the Smooth Muscle K ATP Channel Case

Multisite phosphorylation mechanism for protein kinase A activation of the smooth muscle ATP-sensitive K+ channel.

The activation of ATP-sensitive K+ channels by protein kinase A in vascular smooth muscle is an important component of the action of vasodilators. In this study, we examine the molecular mechanisms of regulation of the cloned equivalent of this channel comprising the sulfonylurea receptor 2B and the inward rectifier 6.1 subunit (SUR2B/Kir6.1). Specifically, we focus on whether the channel is di...

Verdict in the smooth muscle KATP channel case: guilty of blood pressure control but innocent of sudden death phenotype.

Effect of ATP-Dependent K+ Channel Openers and Blockers on Serum Concentration of Aldosterone in Rats

There are many reports for involvement of ATP-sensitive potassium channels in pancreatic, cardiac and vascular smooth muscle cells. This study examined the effect of single doses of K+ channel openers diazoxide, minoxidil and K+ channel blockers chlorpropamide, glibenclamide on serum concentration of aldosterone in male rats. Blood samples were obtained 60 minutes after drug treatment and serum...

Inhibition by protein kinase C of the K(NDP) subtype of vascular smooth muscle ATP-sensitive potassium channel.

ATP-sensitive K(+) channels (K(ATP)) contribute to the regulation of tone in vascular smooth muscle cells. We determined the effects of protein kinase C (PKC) activation on the nucleoside diphosphate-activated (K(NDP)) subtype of vascular smooth muscle K(ATP) channel. Phorbol 12,13-dibutyrate (PdBu) and angiotensin II inhibited K(NDP) activity of C-A patches of rabbit portal vein (PV) myocytes,...

Alteration of ATP-sensitive K+ channels in rabbit aortic smooth muscle during left ventricular hypertrophy.

We investigated the impairment of ATP-sensitive K(+) (K(ATP)) channels in aortic smooth muscle cells (ASMCs) from isoproterenol-induced hypertrophied rabbits. The amplitude of K(ATP) channels induced by the K(ATP) channel opener pinacidil (10 μM) was greater in ASMCs from control than from hypertrophied animals. In phenylephrine-preconstricted aortic rings, pinacidil induced relaxation in a dos...