N omega-nitro-L-arginine methyl ester interferes with pentylenetetrazol-induced kindling and has no effect on changes in glutamate binding.

The effects of N omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, on seizure development and processes of glutamate neurotransmission were studied in the pentylenetetrazol (PTZ)-kindled rats. For this purpose, a dose of 10 mg/kg L-NAME was injected prior to the 13 kindling stimulations. Eight days after the final injection, glutamate binding to brain membranes was measured. It was shown that L-NAME suppressed the kindling development significantly. Furthermore, L-NAME-pretreated rats showed lower seizure scores in reaction to a challenge dose of PTZ. However, glutamate binding was not changed by the pretreatment. The data suggest an involvement of NO in the mechanisms related with kindling.