Fig. 4.
The effect of GDPβS on SRIF-induced changes in IK. a, K+ currents were recorded with a patch pipette containing 500 μm GDPβS in control solution and after a 5 min exposure to 0.5 μm SRIF.b, The I–V relationship ofIK obtained from the experiments described in a indicates that SRIF failed to alterIK in the presence of GDPβS.c, The histogram summarizes SRIF-induced changes inIK when the internal solution contained GTP (openbar) and when GTP was replaced by GDPβS (hatchedbar) to block G-protein activation.