Effect of PGF2 alpha and 15(S)-15-methyl PGE2 methyl ester on feline generalized penicillin epilepsy.

The effect of PGF2alpha and 15(S)-15-methyl PGE2 methyl ester on transient generalized epilepsy in the cat induced by penicillin was examined. Epileptic activity before and after administration of the prostaglandins by several routes was determined from continuous EEG recordings and expressed in epileptic bursts per min. The PGE2 analogue given in single non-toxic doses (1.6-3 mug/kg) by intramuscular or intravenous routes at the peak of epileptic activity significantly reduced epileptic activity for up to four hours. Subcutaneous administration was less effective. PG2alpha given by the intramuscular route (0.3 mg/kg) also markedly reduced the number of epileptic bursts. Increasing the dosage 4-fold almost completely suppressed epileptic activity. Intracarotid infusion of PGF2alpha for one hour (10 mug/min) almost abolished all epileptic activity. Neither prostaglandin given in non-toxic doses induced EEG abnormalities in non-epileptic cats. Toxic doses of the E2 analogue (greater than 16 mug/kg) caused bilaterally synchronous high voltage slow wave activity. It is concluded that these prostaglandins reduce penicillin epilepsy in the cat. The findings are consistent with either a direct excitatory action on neurones of the medial reticular formation or anatagonism of the depressant action of norepinephrine on Purkinje cells.