Inactivation of cGMP‐dependent conductance of rod outer segment plasma membrane induced bij cGMP

Abstract
Integral cGMP‐dependent currents as well as activity of single cGMP‐activated channels in plasma membrane of rod outer segment (ROS) were recorded using the patch‐clamp method. The dependence of integral currents on cGMP concentration is shown to be bell‐shaped. Decrease in cGMP‐dependent conductance at high cGMP concentration results from a decrease in channel opening probability. Thus, cGMP in high concentrations inactivates cGMP‐dependent conductance.