Antipsychotic, antidepressant, anxiolytic, and anticonvulsant drugs induce type II nitric oxide synthase mRNA in rat brain.

Nitric oxide synthase inhibitors have been regarded as potentially beneficial for psychiatric disorders such as depression and schizophrenia, though little is known about how nitric oxide synthases are affected by psychotropic drugs in the brain. Using reverse transcription-polymerase chain reaction analysis, we investigated the effects of short- and long-term oral treatments with several psychotropics on type II nitric oxide synthase gene expression in the rat brain. With maprotiline and fluvoxamine, enzyme mRNA levels were higher after a 28 day treatment than after 1 and 4 day treatments. Zonisamide, carbamazepine and diazepam also increased mRNA, though differences in levels between 1, 4 and 28 day treatments were not significant. These results suggest that psychotropics modulate the gene expression of type-II nitric oxide synthase in the brain.