AJP - Regulatory, Integrative and Comparative Physiology, Vol 258, Issue 1 211-R215, Copyright © 1990 by American Physiological Society
Dexfenfluramine: action with estradiol on food intake and body weight in ovariectomized rats
A. M. Souquet and N. E. Rowland
Department of Psychology, University of Florida, Gainesville 32611.
Previous work from this laboratory has shown that chronic administration of
dexfenfluramine (DF) caused substantial weight loss in rats that were
overweight 3-4 mo after ovariectomy (OVX), but not in OVX rats that were of
normal weight, as a result of estrogen replacement. The present study was
conducted to determine whether the enhanced weight loss in the former group
is because of either overweight per se or an inhibitory effect of estrogen
on DF. Starting either 0, 6, or 14 wk after OVX, when weight gain was zero,
moderate, or near maximal, respectively, rats received a 12-day regimen of
either estradiol or the oil vehicle and either DF (3 mg.kg-1.day-1 by
osmotic minipump) or no drug. DF had no effect on either food intake or
weight gain of groups treated during 0-2 wk after OVX but had significant
anorectic and weight loss actions in groups treated 6-8 and 14-16 wk after
OVX. Estrogen had a similar effect at all three times and in the 14-wk
group produced an effect that was additive with that of DF. Measures of
plasma glucose and triglycerides and adipose tissue lipoprotein lipase
activity did not correlate with the effectiveness of the drug to promote
weight loss.
