MODULATION OF NITRIC-OXIDE PRODUCTION IN-VIVO IN THE BRAIN

Nitric oxide (NO) is a free radical gas that is synthesized from L-arg inine (L-arg) by NO synthase (NOS). Activation of N-methyl-D-aspartate (NMDA), non-NMDA or metabotropic glutamate receptor (mGluR) causes NO formation through NOS activation. We propose that there may be two pa thways for NO production; NOS-dependent and independent pathways. Acti vation of NMDA receptors results in an increase in NO production via t he NOS-dependent pathway whereas activation of non-NMDA receptors or m GluR may produce NO through not only the NOS-dependent pathway bur als o an NOS-independent pathway. Furthermore, it is suggested that glial cells may play a role in modulating NO production by regulating L-Arg availability, (C) 1998 Prous Science. All rights reserved.