Does 3-adrenoreceptor blockade attenuate acute exercise-induced reductions in leptin mRNA?
We investigated the effect of a single bout of exercise on leptin mRNA levels in rat white adipose tissue. Male Sprague-Dawley rats were randomly assigned to an exercise or control group. Acute exercise was performed on a rodent treadmill and was carried out to exhaustion, lasting an average of 85.5 ± 1.5 min. At the end of exercise, soleus muscle and liver glycogen were reduced by 88% (P < 0.001). Acutely exercised animals had lower (P < 0.05) leptin mRNA levels in retroperitoneal but not epididymal fat, and this was independent of fat pad weight. To test the hypothesis that 3-adrenergic-receptor stimulation was involved in the downregulation of leptin mRNA in retroperitoneal fat, a second experiment was performed in which rats were randomized into one of four groups: control, control + 3-antagonist, exercise, and exercise + 3-antagonist. A highly selective 3-antagonist (SR-59230A) or vehicle was given by gavage 30 min before exercise or control experiment. Exercise consisted of 55 mi
