Effects of 4-hydroxyamphetamine on in vivo brown adipose tissue thermogenesis and feeding behavior in the rat.

The influence of 4-hydroxyamphetamine (4-OHAM) on food and water intake and in vivo brown adipose thermogenesis was examined in two experiments. In Experiment 1, female rats were treated with 0.00, 0.25, 0.50, 1.00, or 2.00 mg/kg 4-OHAM (ip) prior to assessment of interscapular brown adipose tissue (IBAT) thermogenesis. The 4-OHAM treatment induced dose-dependent activation of IBAT thermogenesis consistent with the enhanced serum levels of norepinephrine and epinephrine observed in 4-OHAM-treated rats immediately after temperature measurement. In Experiment 2, the influence of 4-OHAM on food and water intake was assessed during 120-min test intervals in female rats fed food and water ad lib. Although there was a trend for 4-OHAM to increase water intake, there was no significant effect of 4-OHAM (0.40, 0.80, 1.00, 2.00, and 4.00 mg/kg) on either food or water intake. These data suggest that brown adipose thermogenesis does not play a role in the anorexia induced by amphetamine or in the regulation of feeding.