Involvement of nitric oxide in noradrenaline-induced increase in blood flow through brown adipose tissue.

N omega-nitro-L-arginine methyl ester (L-NAME) (80 mg), a NO synthase blocker, completely abolished noradrenaline (NA)-induced increase in blood flow through brown adipose tissue (BAT) in the urethan-anesthetized rat. L-NAME suppressed NA-induced increase in blood flow dose-dependently. L-arginine (80 mg), but not D-arginine (80 mg), reversed the inhibitory effect of L-NAME (0.8 mg). NA-induced increase in BAT temperature was also decreased by L-NAME. These results suggest that nitric oxide mediates NA-induced increase in BAT blood flow.