Figure 8.

Effect of ACTH on human adrenal zona glomerulosa (AZG) K⁺ currents. A: A-type K⁺ currents. K⁺ currents were activated by voltage steps to test potentials from −50 to +40 mV, applied at 30 s intervals from a holding potential of −80 mV. Current traces were recorded before and after superfusing cell with ACTH. Peak current amplitudes in the absence and presence of 500 pM ACTH are plotted against test potential. B: K2P current. K⁺ currents were recorded in response to voltage steps to +20 mV applied at 30 s intervals from a holding potential of −80 mV with or without 10 s prepulses to −20 mV. Noninactivating current amplitudes with (open circles) or without (solid circles) prepulses are plotted against time. Numbers on plot correspond to those on traces before and after 1 nM ACTH. Number of independent experiments: n = 4 (A); n = 5 (B).