Metabolism of cyclic 3',5'-AMP injected into the rat brain lateral ventricle

(14C)-cAMP was injected into the lateral ventricle of the rat brain and autoradiographic studies and assay of metabolism of this nucleotide were carried out. (14C)-cAMP rapidly penetrates into the cerebrospinal fluid in other brain ventricles and into the subarachnoidol cerebellar space. 14C was also present in the brain tissue adjacent to the lumen of the ventricles. Given intraventricularly (14C)-cAMP is rapidly metabolized and the presence of 14C in the brain tissue is probably the consequence of the incorporation of metabolites of (14C)-cAMP.