Angiotensin II blocks ATP-sensitive K+ channels in porcine coronary artery smooth muscle cells.
ATP-sensitive K+ channels with small conductance (30 pS in symmetrical K(+)-rich solutions) in porcine coronary artery smooth muscle cells were highly active at physiological concentrations of Ca2+ (greater than 10(-4) M) even in the presence of physiological ATP levels, suggesting that these channels contribute to the generation of the resting membrane potential in vascular smooth muscle cells and their modulation is important in controlling vasomotor tone. Angiotensin II, applied from outside the membrane, blocked these channels in a concentration-dependent manner. This would be expected to cause depolarization and result in vasoconstriction.
Miyoshi
Y
Y
Second Department of Internal Medicine, School of Medicine, University of Tokushima, Japan.
Nakaya
Y
Y
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects / Q000502:physiology*; D004553:Electric Conductivity; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000502:physiology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D013552:Swine
D015221:Potassium Channels; D000804:Angiotensin II; D000255:Adenosine Triphosphate; D002118:Calcium