Multiple cyclic nucleotide phosphodiesterases in rat kidney

Using DEAE-cellulose chromatography and Agarose gel filtration we have partially purified a low Km cyclic adenosine monophosphate (AMP) phosphodiesterase from the 100,000 X g supernatant of rat kidneys. The characteristics of this enzyme included a Km of approximately 4 muM a pH optimum of around 8.0 and a requirement for magnesium. This preparation should be suitable for investigation of possible effects of hormones, drugs and cellular constituents on the cyclic AMP pathway through any direct effects on the low Km enzyme. We have also demonstrated a nonspecific, high Km cyclic nucleotide phosphodiesterase and possibly a specific cyclic guanosine monophosphate (GMP) phosphodiesterase in the soluble fraction from rat kidneys.