ACTIVITY OF S-ADENOSYLMETHIONINE DECARBOXYLASE, A KEY REGULATORY ENZYME IN POLYAMINE BIOSYNTHESIS, IS INCREASED IN EPILEPTOGENIC HUMAN CORTEX

Objective: We measured the activity of S-adenosylmethionine decarboxyl ase, a key regulatory enzyme of polyamine biosynthesis, in the tempora l cortex of patients with epilepsy. Design: Cortical surgical specimen s were obtained following anterior temporal lobe resection for intract able epilepsy. Enzyme activity was compared in nonepileptogenic (n=16) and epileptogenic (spontaneously discharging; n=19) regions. Results: Mean enzyme activity was increased by 44% in samples from epileptogen ic cortex compared with samples from nonepileptic regions. The S-adeno sylmethionine decarboxylase activity in regions of focal epileptogenic discharges was also increased in five patients compared with paired s amples from the nonepileptogenic portion of the same gyrus (+55%). Con clusions: Elevated activity of S-adenosylmethionine decarboxylase in r egions of active epileptogenic cortical discharges suggests that a dis turbance of the polyamine system may be involved in the maintenance of hypersynchronous discharges, perhaps through a modulatory action at t he excitatory N-methyl-D-aspartate-preferring glutamate receptor.