Distribution of exogenous cyclic adenosine 3', 5'-monophosphate in rabbits and cats.

The appearance and disapperance of total radioactivity in plasma and cerebrospinal fluid (CSF) were studied after a single intravenous injection of tritium-labelled cyclic adenosine 3', 5'-monophosphate (cAMP) into rabbits and cats. The radioactivity was rapidly cleared both from plasma and relatively stable when compared to plasma cAMP level. Exogenous cAMP in plasma does not seen to distribute into CSF by a simple diffusion.