Cyclic AMP modulates electrical excitability of insect oöcytes (Rhodnius prolixus)

The effects of cyclic AMP on resting potentials and calcium action potentials in Rhodnius oöcytes have been investigated using intracellular recording techniques. Extracellular application of cyclic AMP or either of two phosphodiesterase-resistant derivatives, 8-bromo-cAMP and 8-(4-chlorophenylthio)-cAMP, was associated with a progressive decline in action potential overshoot and duration and the appearance of a hyperpolarizing afterpotential. …