Influence of dehydroepiandrosterone (DHEA) on the thyroid hormone status of BHE/cdb rats

Abstract

The effects of dehydroepiandrosterone treatment on the thyroid status of prediabetic, male BHE/cdb rats were investigated. Five-week old BHE/cdb rats fed a 65% glucose diet were injected intraperitoneally daily with either dehydroepiandrosterone (0.35 mol/kg body weight) or vehicle (1 mL/kg body weight) for 8 weeks. Organ weights, body composition, resting oxygen consumption, serum thyroxine, triiodothyronine, triglycerides, glucose and insulin, and thyroxine 5′-deiodinase activity in liver, brown adipose tissue, kidney, and pituitary were determined. Dehydroepiandrosterone-treated rats weighed significantly less at the end of the study than the control rats. Food intake was not different ( P ≥ 0.05) between groups. Dehydroepiandrosterone treatment decreased epididymal and retroperitoneal fat pad weights, carcass energy, total and free serum thyroxine levels, thyroxine: triiodothyronine ratios, and hepatic and pituitary 5′-deiodinase activities, and increased resting oxygen consumption, liver weights, liver protein, renal weights, and body ash. Dehydroepiandrosterone was without effect on the other parameters. These data suggest that dehydroepiandrosterone alters thyroid hormone status and in so doing, affects energy balance by increasing metabolic rate and decreasing fat stores.