KINETICS OF AGONIST CONDUCTANCE CHANGES DURING HYPERPOLARIZATION AT FROG END-PLATES (REPRINTED FROM BRIT J PHARMACOL, VOL 53, PG 308-310, 1974)

The effect of rapid hyperpolarization on acetylcholine- or carbachol-i nduced currents was studied at voltage clamped frog endplates. Followi ng a hyperpolarizing step the agonist-induced conductance increased ap proximately exponentially to a new level. The rate constant for this p rocess was smaller during hyperpolarization or lowered temperature, an d was also smaller for acetylcholine than for carbachol. The results a re interpreted in terms of a potential-dependent conformational change of the receptor.