THE ROLE OF BETA-ADRENOCEPTORS AND ALPHA-ADRENOCEPTORS ON BLOOD-FLOW AND TEMPERATURE OF BROWN ADIPOSE-TISSUE AND INVOLVEMENT OF NITRIC-OXIDE IN THEIR EFFECTS

1. Isoproterenol increased interscapular brown adipose tissue (BAT) bl ood flow and temperature. 2. Phenylephrine increased BAT temperature, but did not affect blood flow. The effect was completely suppressed by N-omega-nitro-L-arginine methyl ester (L-NAME), an inhibitor of endog enous NO synthesis. 3. Isoproterenol plus phenylephrine increased BAT blood flow and temperature earlier than isoproterenol alone. 4. CL316, 243 increased BAT blood flow and temperature. These effects were also inhibited by L-NAME. 5. These data suggest that BAT blood flow as well as thermogenesis is regulated mainly by beta-adrenoreceptors and part ly by alpha(1)-adrenoreceptors, and NO may be a common mediator for th eir regulations. Copyright (C) 1996 Elsevier Science Ltd.