Effects of Adrenalectomy on Body Weight and the Size and Number of Fat Cells in the Zucker (Fatty) Rat

Abstract

Adrenalectomy reduced food intake and the rate of weight gain in the Zucker (fatty) rat to levels indistinguishable from normal. The size of adipocytes in the retroperitoneal and perimetrial fat pads also decreased after adrenalectomy but the number of fat cells in each of these depots increased to reach levels not different from those in the sham-operated fatty rat. Fat accretion in the intact fatty rat was characterized by both hyperplasia and hypertrophy of the fat cells, but in the adrenalectomized Zucker rats, weight gain was accompanied by hyperplasia and decreased fat cell size. These data show that adrenalectomy can prevent most of the phenotypic expression of the genetic defect in the fatty rat and challenge the concept that reduced food intake can prevent hyperplasia of fat cells.