Effects of 1, 9-dideoxy forskolin on delayed rectifier potassium current of bullfrog dorsal root ganglion cells.

Whole-cell voltage-clamp recordings were made from cultured bullfrog dorsal root ganglion cells to examine the channel blocking activity of 20 microM of 1, 9-dideoxy forskolin (d-FSK) on the delayed rectifier potassium current. The drug reduced the maximum amplitude of the current (10-20 nA at +65 mV) by 40-80%. However, the voltages for 50%-activation (approximately -12 mV) and for 50%-inactivation (approximately -37 mV) remained unaffected by d-FSK. These results indicate that the channel block by d-FSK occurs in a voltage-independent manner.