Seizures induced by α‐guanidinoglutaric acid, a nitric oxide synthase inhibitor, are controlled by l‐arginine

Abstract

We evaluated the effect of manipulation of nitric oxide (NO) synthesis on epileptiform discharges recorded from immobilized rats during intracerebroventricular injection of c~-guanidinoglutaric acid (GGA), an endogenous convulsant and a NO synthase (NOS) inhibitor, alone or in combined with a NOS substrate, 1~ arginine (ARG). GGA alone, or combined with SO mM ARG, resulted in prolonged electrographical seizures while co-injection of either 100 or 200 mM of ARG with GGA caused significantly protection. These data show that ARG inhibited epileptiform discharges in a dose-dependent fashion, suggesting that the discharges initiated by inhibition of NOS with the intrinsic convulsant GGA are abated by increasing the concentration of the NOS substrate ARG.