Ca^<2+>依存性K^+チャネル : その分布,機能及び制御

概要

論文の詳細を見る
Calcium - dependent potassium (K_<ca>) channels are found in a wide variety of tissues. K_<ca> channels are highly permeable to potassium over sodium and have sensitivity of channel gating to intracellular calcium. K_<ca> channels can be grouped into three broad classes based on their conductances : large-con-ductance K_<ca>(Maxi - K or BK) channels with single - channel conductances greater than about 150 pS, small - conductance K_<ca> (SK) channels of less than 50 pS, and intermediate - conductance K_<ca> (IK) channels with conductances 50〜150 pS. In excitable cells, the K_<ca> channel contributes to the repolarization of cell membranes after the action potential and production of afterhyperpolarization. K_<ca> channels are important in repolarization of Ca^<2+> action potential and contribute to the relaxation of smooth muscle. In nonexcitable cells, the Kc* channel contributes to the regulation of fliud secretion in exocrine gland cells. The gating of K_<ca> channels is sensitive to both intracellular Ca^<2+> and membrane voltage. Moreover, Studies from the last few years have shown that cAMP - dependent protein phosphorylation modulates the gating of K_<ca> channel. The information given in this review highlights a new model for regulating of the gating of the K_<ca> channel.
東海大学の論文
1993-03-30