Effect of Adrenalectomy on Adipose Tissue and Liver in Rats with Acute Insulin Deficiency

Abstract

Effects of adrenalectomy on adipose tissue and liver lipogenesis were studied in rats with acute insulin deficiency induced either by interrupting insulin administration to previously treated alloxan-diabetic rats or by almost completely removing pancreatic tissue in a convenient two-stage procedure. The adrenals were removed at the time insulin deficiency was induced and the effects of excision were determined within the next twenty-four hours. Adrenalectomy prevented the marked reduction in incorporation of 14-C from glucose and acetate into fatty acids, as well as the decrease in carbon dioxide production from hexose, in vitro, which rapidly ensue in adipose tissue from alloxan-diabetic rats following insulin withdrawal. In the same conditions, adrenal removal did not affect the metabolism of U-14-C-glucose by liver slices, but a small increase in liver fatty acid synthesis from acetate was observed during one of the experimental intervals. In similarly designed experiments, adrenalectomy increased the recovery of 14-C from acetate, administered in vivo, from fatty acids of the carcass and liver of alloxan-diabetic animals. The effects of adrenalectomy on the metabolism of U-14-C-glucose by adipose tissue from pancreatectomized rats were similar to those observed in alloxandiabetic rats although less marked. Again, adrenal removal did not affect glucose metabolism by liver slices from pancreatectomized rats, but improved liver lipogenesis from acetate. The present results, compared with others in the literature, suggest that the effects of adrenal excision are fully manifested only if the glands are removed before the metabolic changes induced by diabetes in adipose tissue are well established.