NA- A STUDY IN THE PILOCARPINE MODEL OF EPILEPSY(K+ ATPASE ACTIVITY IN THE RAT HIPPOCAMPUS )

Biochemical abnormalities have been implicated in possible mechanisms underlying the epileptic phenomena. Some of these alterations include changes in the activity of several enzymes present in epileptic tissue s. Systemic administration of pilocarpine in rats induces electrograph ic and behavioral limbic seizures and status epilepticus, that is foll owed by a transient seizure-free period (silent period). Finally a chr onic phase ensues, characterized by spontaneous and recurrent seizures (chronic period), that last for the rest of the animal's life. The pr esent work aimed to study the activity of the enzyme Na+ K+ ATPase, in rat hippocampus, during the three phases of this epilepsy model. The enzyme activity was determined at different time points from pilocarpi ne administration (1 and 24 h of status epilepticus. during the silent and chronic period) using a spectrophotometric assay previously descr ibed by Mishra and Delivoria-Papadopoulos [Neurochem. Res. (1988) 13, 765-770]. The results showed decreased enzyme activities during the ac ute and silent periods and increased Na+ K+ ATPase activity during the chronic phase. These data show that changes in Na+ K+ ATPase activity could be involved in the appearance of spontaneous and recurrent seiz ures following brain damage induced by pilocarpine injection. Copyrigh t (C) 1996 Elsevier Science Ltd.