Castration-Induced Obesity in Mice.

Abstract

Body composition and histology of the adrenal cortex and the islets of Langerhans were compared in yellow-obese mice, their intact non-obese littermates and their castrated, originally non-obese littermates. In our colony, yellow females were heavier and fatter than males. Obesity developed in yellow mice of both sexes which were fed a commercial diet containing 12% fat. The extractable body fat of the yellow animals was more than twice as high as that of controls. The fat content of gonadectomized animals was significantly higher than that of the yellow obese mice although their average body weight was slightly less. The adrenal cortex of the castrates showed subcapsular hypertrophy, and the islets of the pancreas were enlarged due to hypertrophy and hyperplasia of the beta cells. The literature concerning obesity and adrenal cortical and islet changes, after castration, has been reviewed and the thesis has been discussed that cortical changes after castration stimulate accelerated release of insulin and obesity.

Human Body Composition

“…Castrated male mice weigh more, and have 2-3 times as much body fat and 13% less body protein than controls (Hausberger and Hausberger, 1966). Castrated female mice are also fatter than controls, but total body protein content is about the same.…”

Effects of Estrogen on Food Intake, Body Weight, and Temperature of Male and Female Obese Mice

“…Bilateral ovariectomy leads to weight gain with the distribution of growth about equally divided between increased fat content and lean body mass (1)(2)(3)(4). Replacement with estrogens causes weight loss and reduced growth rates until normal values are achieved (1,2,5).…”

Response of Serum Insulin Concentration to Tumor Growth in Different Genetic Systems

“…A 5 to 7 fold increase in serum insulin levels in mice within 1 to 3 days after injection of cortisone has been reported (Rastag;and Campbell, 1969); the latter effect was dependent on cortisone dosage. Hypertrophy of the islets of Langerhans and hypertrophy and hyperplasia of the beta cells in castrated aja YS males and in intact AYja YS males (Hausberger and Hausberger, 1966) as weil as in intact AY jmales of a different strain (Hellerström and Hel/mann, 1963) have been observed. Differences between the YS and VY strains in the response of the adrenal cortex to castration may be indicated by the differences between these strains in the response of liver wet weight to castration (WollI, 1970b).…”

“…The response of the adrenal cortex to such stress is therefore of primary importance in the interpretation of metabolie alterations in mice bearing such tumors. Castration also profoundly affects the adrenal cortex in mice via the anterior hypophysis (Hausberger and Hausberger, 1966) and this response is under genetic control (Dickie and Lane, 1956). Hypersecretion of glucocorticoids is accompanied by elevated serum insulin levels (Sneyd, 1963(Sneyd, , 1964.…”