In general, treatment of mice and rats with dehydroepiandrosterone (DHEA) has been shown to result in a decrease in body weight gain without an effect on food intake. The obese Zucker rat has been the exception. The present study compares the response of DHEA-treated obese rats to both ad libitum-fed and pair-fed obese groups. Body weight, weight gain and food efficiency ratio were all significantly decreased in DHEA-treated rats compared with either ad libitum-fed or pair-fed rats. Liver weight was higher and heart weight lower in the DHEA-treated group in comparison to both control groups. Retroperitoneal fat pad weight was lowered in DHEA-treated rats by over 60% compared to both pair-fed rats and ad libitum-fed rats. Similar results were found for parametrial fat pads. Neither fecal fat excretion nor urinary output were altered by DHEA treatment. The finding of greater activity of the enzyme, long chain acyl-CoA hydrolase, in DHEA-treated but not in either ad libitum-fed or pair-fed rats, supports our hypothesis that DHEA may induce a futile cycle of fatty acid metabolism leading to enhanced energy utilization. These results support fundamentally different effects of DHEA compared to a decreased food intake in the obese Zucker rat.
- dehydroepiandrosterone (DHEA)
- long chain acyl-CoA hydrolase