Anorexia after adrenalectomy in gold thioglucose-treated obese mice: role of adipose tissue mass.

We have previously shown that following adrenalectomy, gold thioglucose (GTG)-treated hyperphagic obese mice exhibit anorexia, weight loss and a pronounced hypoglycemia which leads ultimately to their death. In the present study, we sought to determine whether the increased adipose tissue mass which is characteristic of GTG-treated obese mice exerted a role in the onset and development of anorexia after adrenalectomy. Accordingly, the effects of adrenalectomy on food intake, weight gain, plasma glucose and corticosterone levels were investigated in normal untreated controls, GTG-treated hyperphagic obese mice and GTG-treated non obese mice. The GTG-treated non obese mice were prepared by restricting their daily intake of chow (pair-feeding) to that consumed by normal untreated mice. After adrenalectomy, all mice were allowed free access to food. As expected, all GTG-treated hyperphagic obese mice exhibited anorexia and weight loss following adrenalectomy. In contrast, about half (52%) of the GTG-treated non obese mice exhibited anorexia and weight loss after adrenalectomy. The response of the GTG-treated non obese adrenalectomized mice was not due to differences in adrenal insufficiency since all adrenalectomized mice had blood levels of corticosterone of less than 0.5 microgram%. These findings indicate that whereas the increased adipose tissue mass of the GTG-treated obese mice appears to be associated with an increased incidence of anorexia following adrenalectomy, increased adipose tissue mass alone does not appear to be essential for the occurrence of anorexia.