Effect of adrenalectomy on weight gain and body composition of yellow obese mice (Ay/a).

It has been reported that the adrenal gland is essential to the development of obesity if Ay/a Yellow obese mice (Hausberger and Hausberger 1960). Since the actual body composition data to support this report has not been published, we attempted to duplicate this observation by adrenalectomy of the Yellow mice before the onset of obesity. Two groups of Yellow mice (Ay/a) and normal mice (a/a) were either sham operated or adrenalectomized at two months of age and at four months of age. Body weight was monitored until body gain had stopped. At that time the animals were sacrified and checked for completeness of adrenal removal. Body composition of dry matter, fat, protein, and ash was determined. Adrenalectomy caused a reduction of body fat of 33% and 30% in both the a/a Control and the Ay/a Yellow mice, respectively. The adrenalectomized Yellow mice were still fatter than adrenalectomized Controls (25.3% fat vs. 10.6% fat). Yellow and control adrenalectomized mice showed similar depression in growth rate. These data suggest that while the adrenal gland is essential for complete expression of the genetic potential for fat deposition, it may not be necessary for partial expression indicating a secondary role in the development of obesity in the Ay/a Yellow mouse.