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Effect of a long-term percutaneous adrenal steroid treatment on rat adipose tissue metabolism
P Mauriège1, D Langin, V Montminy
1CHUQ Medical Research Center, Department of Physiology, Laval University, Ste-Foy, Québec, Canada.
Objective:
To examine some cellular mechanisms which regulate adipose cell metabolism in ovariectomized (OVX) and intact rats subjected or not to dehydroepiandrosterone (DHEA).
Design:
Rats were assigned to one of four treatment groups for 27 weeks. The main effects tested were castration (-or+) and DHEA treatment (-or+) which 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 levels, and HDL-cholesterol (C) concentrations; lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) activities.
Results:
No difference in body composition and RP fat pad weight was observed between the intact and intact-DHEA groups. LPL and HSL activities were also similar in both groups. The increased weight of OVX rats was paralleled by a higher adiposity and greater RP adipose tissue mass, which was associated 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 displayed 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 whereas plasma HDL-C concentrations were increased in intact-DHEA and OVX-DHEA rats.
Conclusion:
These results show that the antiobesity effects of DHEA are dependent upon the ovarian status of the animal. These effects may involve changes in the lipid storage and the mobilization capacity of adipose tissue.