The influence of blocking drugs on epinephrine-induced effects on carbohydrate metabolism

Thesis (Ph.D)--Boston UniversityUnder conditions of general body stress, the adrenal medulla is called upon to secrete its hormone, epinephrine. As a result of the influences of this hormone, a variety of changes in the resting physiology of the organism are incurred, which usually aid the individual in meeting the stressful challenge. One of the first changes which is known to occur as a result of the action of endogenous or exogenous epinephrine is a generalized hyperglycemia. Although this fundamental observation has been known for half a century, a complete understanding of the mechanism of action is still lacking. In the fasting animal, it could logically result from an increased liver glycogenolysis and/or a decreased glucose uptake by the tissues. A review of the literature has shown that whereas all workers are agreed on an increased liver glycogenolysis as a result of epinephrine activity, they are far from agreement on the latter phase, the glucose uptake. The results of this study indicate that much of the confusion is due to a misuse of terms, for it has been domnstrated that, at least in vitro, the glucose uptake of muscle tissue increases, while the amount of glucose utilized decreases following epinephrine. The extra glucose is stored in the form of hexosemonophosphate. [TRUNCATED