Large conductance Ca^2+-activated K^+(maxi-K) channels were studies using inside-out patches of smooth muscle cells from human uterine artery. Single smooth muscle cells were obtained through proteolytic enzyme digestion and the patch clamp tecnique w...
Large conductance Ca^2+-activated K^+(maxi-K) channels were studies using inside-out patches of smooth muscle cells from human uterine artery. Single smooth muscle cells were obtained through proteolytic enzyme digestion and the patch clamp tecnique was used. The maxi-K channel showed a single channel conductance of about 150 pS in physiological concentration of K^+on both sides of the patch. The channel activity was dependent on intracellular Ca^2+ concentration change. ATP increased the channel activity dose-dependently and the effect was reversible. Okadaic acid(100 nM) increased the channel activity in the presence of ATP.
From these results it is strongly suggested that maxi-K channels of human uterine arterial smooth muscle cells were modulated by protein kinase/phosphatase action through membrane-delimited pathway.