Effects of reserpine and adrenal demedullation on brown adipose tissue thermogenesis induced by dl-phenylpropanolamine.

The contribution of catecholamine release to activation of brown adipose tissue (BAT) thermogenesis induced by dl-phenylpropanolamine (dl-PPA) was assessed in adult male rats. The rats underwent adrenal demedullation or not and were then treated (2X) with 5 mg/kg reserpine or 0.9% saline over a 24 hour period. Interscapular BAT (IBAT) and rectal temperatures were recorded for 10 minutes prior to and 30 minutes following treatment were induced by dl-PPA. Significant increases in IBAT temperature were induced by dl-PPA treatment in sham-operated and demedullated rats but but not in sham-operated or demedullated rats treated with reserpine. The action of reserpine on IBAT thermogenesis induced by PPA was not an artifact of reduced feeding associated with reserpine treatment as rats deprived of food for 24 hours exhibited normal thermogenesis to 10 mg/kg dl-PPA. These data document the role of non-adrenal catecholamines in IBAT thermogenesis induced by dl-PPA.