Long-term oral administration of dehydroepiandrosterone has different effects on energy intake of young lean and obese male Zucker rats when compared to controls of similar metabolic body size.
OBJECTIVE
The effects of dehydroepiandrosterone (DHEA) on appetite and weight in the Zucker rat have been examined by many investigators who have reported appetite suppression and metabolic effects. However, these studies compared the treated animals to controls of a similar age. Since animals of different sizes consume different amounts of food, perhaps the treated animals should be compared to controls of a similar size. We studied the effects of DHEA on energy intake and weight gain and analysed the effects by age and metabolic body size.


METHODS
Lean (n = 21) and obese (n = 16) male Zucker rats were fed plain chow or chow containing 6 g DHEA/kg chow (0.6% wt/wt) from age 4 wk to 20 wk. Daily energy intakes and body weights were determined at least once weekly.


RESULTS
As expected, the lean and obese rats given DHEA exhibited less daily energy intake (kJ/d) and less weight gain than their respective controls of the same age. The lean rats given DHEA did not exhibit any difference in daily energy intake when determined relative to body weight (b.w.) (kJ x d-1 x g b.w.-1) compared to lean controls of the same metabolic body size, while the obese rats given DHEA exhibited less daily energy intake relative to b.w. (kJ x d-1 x g b.w.-1) compared to obese control of the same metabolic body size.


CONCLUSIONS
Though DHEA reduced total energy intake among the lean and obese Zucker rats, only the obese rats exhibited less energy intake relative to b.w. compared to controls of the same metabolic body size. Thus, DHEA may exert different effects on energy intake relative to b.w. in lean and obese Zucker rats and perhaps the lean Zucker rat is a better model for evaluating the metabolic effects of DHEA since it does not exhibit any effect on energy intake relative to b.w. compared to rats of the same metabolic body size.
Obesity Research Program, Department of Medicine, Section of Endocrinology, LSU Medical Center,1542 Tulane Avenue, Box T4M-5, New Orleans, LA, 70112-2822 USA. richards@lsumc.edu
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D000818:Animals; D001824:Body Constitution; D001835:Body Weight / Q000187:drug effects; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D002149:Energy Intake / Q000187:drug effects*; D006579:Heterozygote; D006720:Homozygote; D008297:Male; D009765:Obesity / Q000235:genetics / Q000503:physiopathology*; D051381:Rats; D011924:Rats, Zucker; D012016:Reference Values; D012044:Regression Analysis; D013851:Thinness
D003687:Dehydroepiandrosterone