Characterization of cyclic nucleotide phosphodiesterases in Xenopus laevis ovary

Abstract

1. 1. A cGMP-stimulated cyclic nucleotide phosphodiesterase present in cytosol of Xenopus laevis ovary has been purified and characterized. 2. 2. A cAMP-specific phosphodiesterase which is not activated by either cGMP or calmodulin, has also been characterized. 3. 3. Brief exposure of intact oocytes to 10 μM progesterone results in an increase in activity of the cAMP-specific enzyme. The cGMP-stimulated and the calmodulin-activated phosphodiesterases are not altered. 4. 4. Changes in cyclic nucleotide levels during progesterone-induced maturation of oocytes may be modulated by these isoenzymes.