Cyclic adenosine 3’,5’-monophosphate (cAMP) concentration and aspartate amino transferase (ASAT or GOT) activity were measured from cerebrospinal fluid (CSF) of rabbits before and after electrically induced convulsions. The convulsions caused a significant increase in CSF cAMP concentration. The treatment with phenobarbital, diphenylhydantoin and carbamazepine for 7 days decreased the basal cAMP values in CSF and partly inhibited the rise after the convulsions. The alterations in ASAT activity were parallel, but less striking. The present results suggest the involvement of cAMP in epileptic discharge and in the mechanism of action of anticonvulsa