Quinidine blockage of K+ channels in the basolateral membrane of larval bullfrog skin.
The skin of frog larvae (Rana catesbeiana) was used to study the characteristics of basolateral K+ channels with fluctuation analysis. K2SO4 and Na2SO4 Ringer's were used as mucosal and serosal solution, respectively. After addition of Nystatin (138 U/ml) the transepithelial conductance and short-circuit current (Isc) increased considerably. Most of Isc was carried by K+, moving from the mucosal to the serosal side. This current could be depressed by quinidine, added to both compartments or to mucosal side only. Fluctuation analysis showed that quinidine induced a Lorentzian component in the power density spectrum. Assuming pseudo-first order kinetics for the channel occlusion by quinidine the current through the open K+ channel and channel density were calculated: iK = 0.22 pA, M = 7.7 channels/microns2.
Van Driessche
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Hillyard
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D000818:Animals; D002462:Cell Membrane / Q000502:physiology; D004553:Electric Conductivity / Q000187:drug effects; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D009092:Mucous Membrane / Q000187:drug effects / Q000502:physiology; D011802:Quinidine / Q000494:pharmacology*; D011892:Rana catesbeiana; D012867:Skin / Q000187:drug effects; D012879:Skin Physiological Phenomena
D007473:Ion Channels; D011802:Quinidine