Kinetic differences between Ca(2+)-dependent K+ channels in smooth muscle cells isolated from normal and atherosclerotic human aorta.
The properties of large conductance Ca(2+)-dependent K+ channels in smooth muscle cells (SMC) isolated from normal and atherosclerotic human aorta were studied using the patch-clamp technique. It was shown that SMC from normal human aorta possess a homogeneous population of normal Ca(2+)-dependent K+ channels. In atherosclerotic aorta two kinetically different types of these channels could be distinguished: along with normal 'long' (L)-type channels there appeared channels of 'short' (s)-type. Under similar conditions s-type channels had about a four times shorter mean open time. About five times higher [Ca2+]in was necessary for s-type channels to reach the probability of the channels being open equal to L-type channels. No differences in conductance and voltage dependency were found between the two channel types. Channels of the s-type resembled those previously described in SMC isolated from foetal human aorta. Thus, it can be suggested that during the development of atherosclerosis a population of SMC with s-type Ca(2+)-dependent K+ channels appears in human aorta.
Institute of Experimental Cardiology, Cardiology Research Centre of the U.S.S.R. Academy of Sciences, Moscow.
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Bolotina
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M
Gericke
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Bregestovski
D000328:Adult; D001011:Aorta / Q000378:metabolism; D001161:Arteriosclerosis / Q000209:etiology / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D004553:Electric Conductivity; D006801:Humans; D007700:Kinetics; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D015221:Potassium Channels / Q000378:metabolism*
D015221:Potassium Channels; D002118:Calcium