Recovery of white adipose tissue after lipectomy in female ground squirrels

Abstract

Female golden-mantled ground squirrels were subjected to surgical removal of adipose tissue (lipectomy) at 4 months of age. Compensation for the 9.6% reduction in body mass effected by lipectomy was observed within 2 weeks and body mass did not differ between lipectomized and sham-lipectomized groups from that time to the conclusion of the experiment. At the time of the second peak in body mass, approximately 11 months postoperatively, lipectomized and sham-lipectomized groups did not differ with respect to total carcass lipid content, water content, or fat-free dry mass. Restoration of body mass after lipectomy did not involve measurable increases in food consumption. There was complete restoration of the retroperitoneal fat depot, but little if any recovery in the parametrial fat depot which was reduced in mass by 75% relative to that of the sham-lipectomized squirrels. Precise regulation of the adipose tissue mass is an important component of the annual cycle in energy balance of female squirrels.