We examined the modulation of nitric oxide production in vivo by measuring levels of nitrite (NO2/-) and nitrate (NO3/-) in the dialysate of the cerebellum in conscious rats, by using an in vivo brain microdialysis technique. The levels of both NO2/- and NO3/- were decreased by the intraperitoneal injection of N(G)-nitro-L-arginine methyl ester, an inhibitor of nitric oxide synthase, whereas N(G)-nitro-D-arginine methyl ester had no effect. L-Arginine by itself increased NO2/- and NO3/- levels and diminished the reduction of their levels caused by N(G)-nitro-L-arginine methyl ester. Direct infusion of L-glutamate, N-methyl-D-aspartate, or KCl into the cerebellum through a dialysis probe resulted in an increase in NO2/- and/or NO3/- levels. The effects of N-methyl-D-aspartate and KCl were dependent on extracellular calcium. Furthermore, the stimulatory effects of L-glutamate and N-methyl-D-aspartate were inhibited by N(G)-nitro-L- arginine methyl ester and (±)-3-(2-carboxypiperazin-4-yl) propyl-1- phosphonic acid (CPP), an N-methyl-D-aspartate receptor antagonist. These results suggest that NO2/- and NO3/- levels may be related to nitric oxide production in vivo.
|Number of pages||10|
|Journal||Journal of Neurochemistry|
|Publication status||Published - 01-03-1997|
All Science Journal Classification (ASJC) codes
- Cellular and Molecular Neuroscience