EFFECT OF ADRENALECTOMY ON HYPERGLYCEMIE RESPONSES OF FED AND FASTED RATS TO CATECHOLAMINES.

Summary Adrenalectomy in rats has been shown to enhance the hyperglycemic response mediated by the β-receptor (isoproterenol in the fasted rat) but not that mediated by the α-receptor (norepinephrine in the fed rat). The enhanced β-effect is apparently the result of a greater depletion of muscle glycogen. Hyperglycemic responses to epinephrine in fasted animals are enhanced in the lower dose range and depressed at higher doses. This is explained in terms of the effect of epinephrine on both α- and β-receptors. The importance of using both fed and fasted rats and dose-response curves rather than single doses in assessing the effects of adrenalectomy is demonstrated.