ADRENALECTOMY OF THE OBESE ZUCKER RAT - EFFECTS ON THE FEEDING RESPONSE TO ENTEROSTATIN AND SPECIFIC MESSENGER-RNA LEVELS

The effects of adrenalectomy on the feeding response to enterostatin and the mRNA levels of its parent protein, pancreatic colipase, have been investigated in lean (fa/?) and genetically obese (fa/fa) rats. Adrenalectomy reduced body weight gain and food intake of obese rats. Enterostatin inhibited the intake of high-fat diet in obese rats but not in lean rats. Adrenalectomy reduced food intake of all rats and abolished the response to enterostatin in the obese group. Obese rats had low levels of colipase mRNA, but these were normalized after adrenalectomy. The ability to respond to exogenous enterostatin is possibly linked to low levels of production of the peptide. The effects of adrenalectomy on brown adipose tissue uncoupling protein (UCP) mRA and beta3-adrenergic receptor (beta3-AR) mRNA were also investigated. Northern blot analysis showed low levels of both UCP mRNA and beta3-AR mRNA in obese rats that were restored to or toward the normal levels of lean rats by adrenalectomy. Adrenalectomy had no significant effects on mRNA levels in lean rats.