Effect of a long-term percutaneous adrenal steroid treatment on rat adipose tissble metabolism

OBJECTIVE: To examine some cellular mechanisms which regulate adipose cell metabolism in ovariectomized (OVX) and intact rats subjected or not to dehy droepiandrosterone [DHEA). DESIGN: Rats were assigned to one of four treatment groups for 27 weeks, Th e main effects tested were castration (-or+) and DHEA treatment (-or+) whic h consisted of a single daily percutaneous application of DHEA cream (30 mg /ml in 50% ethanol - 50% propyleneglycol). SUBJECTS: Forty female Sprague-Dawley rats (sixteen-month old), MEASUREMENTS: Body weight and fat mass (by dual-energy X-ray absorptiometry ), retroperitoneal (RP) fat pad weight; plasma insulin and triglyceride lev els, and HDL-cholesterol (C) concentrations; lipoprotein lipase (LPL) and h ormone-sensitive lipase (HSL) activities. RESULTS: No difference in body composition and RP fat pad weight was observ ed between the intact and intact-DHEA groups. LPL and HSL activities were a lso similar in both groups. The increased weight of OVX rats was paralleled by a higher adiposity and greater RP adipose tissue mass, which was associ ated with both a marked rise in LPL activity and a slight diminution in HSL activity in this depot, compared to intact animals. OVX-DHEA rats displaye d a reduced adiposity and a lighter RP fat depot, which was associated with a decrease in LPL and an increase in HSL activities, compared to untreated OVX animals. Fasting plasma insulin and TG levels were also decreased wher eas plasma HDL-C concentrations were increased in intact-DHEA and OVX-DHEA rats. CONCLUSION: These results show that the antiobesity effects of DHEA are dep endent upon the ovarian status of the animal, These effects may involve cha nges in the lipid storage and the mobilization capacity of adipose tissue.