INCREASED LIPOLYSIS TO BETA-ADRENERGIC STIMULATION AFTER DEHYDROEPIANDROSTERONE TREATMENT IN RATS

Young adult male rats were treated with 4 mg dehydroepiandrosterone (D HEA)/100-g diet for 4 wk or were fed the same purified diet unadultera ted (51 carbohydrate:20 fat: 23.5 protein; wt/wt). After 1 wk body wei ght and fat mass of the DHEA-fed rats were significantly less than the controls. By the end of week 3, fat-free mass of the DHEA rats was le ss than the controls. Neither food intake nor resting metabolism, meas ured by indirect calorimetry, was different between groups. Isolated e pididymal adipocytes of DHEA rats were significantly smaller and isopr oterenol (x10(7) M) stimulation of glycerol release was 53% greater (P < 0.01) than the controls. Basal rate of glycerol release increased s ignificantly for both groups in response to the adenosine inhibitor ad enosine deaminase; there were no significant interaction effects. Inhi bition of lipolysis by the adenosine analogue phenylisopropyladenosine was similar between groups. Findings support the hypothesis that DHEA reduces adiposity directly by increased lipolysis, but the mechanism of action does not involve a change in the antilipolytic function of a denosine.