Voltage dependence of the pharmacological Mg2+ block of the Ca2+ entry into vascular smooth muscle cells.
We studied the voltage dependence of the inhibitory effects of the Ca2+ antagonist Mg2+, compared to nifedipine, on the transsarcolemmal Ca2+ uptake into primary monolayers of smooth muscle cells obtained from pig coronary arteries. The cellular Ca incorporation was analyzed by liquid scintillation. Depolarization was produced by elevation of K+0. The data suggest that depolarization known to improve the inhibition by organic Ca2+ antagonists of L-type voltage-gated Ca2+ channels attenuates the Ca2+ antagonism of Mg2+ at vascular smooth muscle cells.
Fleckenstein-Grün
G
G
Study Group for Calcium Antagonism, Physiological Institute, Freiburg i.Br. Germany.
Matyas
S
S
Dumont
L
L
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002478:Cells, Cultured; D003331:Coronary Vessels / Q000187:drug effects / Q000378:metabolism; D008274:Magnesium / Q000494:pharmacology*; D008564:Membrane Potentials / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology*; D012508:Sarcolemma / Q000187:drug effects / Q000378:metabolism; D013552:Swine
D002121:Calcium Channel Blockers; D008274:Magnesium; D009543:Nifedipine; D002118:Calcium