CYCLIC 3',5'-NUCLEOTIDE PHOSPHODIESTERASE IN BRAIN

The distribution of cyclic 3',5'-nucleotide phosphodiesterase activity in the rabbit central nervous system has been studied with a quantitative micromethod. A wide range of values between various structures was observed, but correlations with cellular density, monoamine content or other enzymes were not apparent. Phosphodiesterase activity is not uniquely associated with particular layers of the cerebral cortex or with specialized synaptic structures in the olfactory bulb. The enzyme level was unaltered in the rat superior cervical ganglion after section of preganglionic fibers, and in the cerebral cortex after lesion of the medial forebrain bundle. Major disparities in comparing these results with those of a Gomori type procedure may be explained in part by the inhibition of the enzyme by lead ion.