Interactions of alcohol and nitric-oxide synthase in the brain

Nitric oxide (NO) is an important molecule associated with both physiological and pathological brain events. Three separate genes encode for nitric-oxide synthase (NOS), the rate-limiting enzyme in NO production, all of which are expressed within brain tissue. Effects of ethanol on NO production may be important to ethanol modification of brain function. Existing data indicate that alcohol exposure alters NOS expression and activity in the brain. Modulation of NOS is suggested to be involved in alcohol-induced behavioral modifications. Furthermore, alcohol-induced changes in NOS may alter immunocompetence, response to injury in the central nervous system, and may be involved in ethanol-mediated neurodegeneration and neurotoxicity. The extent and direction of change in NOS expression and activity depends on cell type and length of exposure. The mechanisms underlying these effects are only partially understood. Herein, the current understanding of the interactions of ethanol and NOS in the brain are discussed.