BEEINFLUSSUNG DER INSULINEMPFINDLICHKEIT DER EVISCERIERTEN RATTE DURCH NEBENNIEREN-EXSTIRPATION, NEBENNIERENHORMONE UND GLUKAGON

Abstract

ABSTRACT Adrenalectomy of eviscerated, nephrectomised rats constantly infused with glucose induces increased glucose consumption. Doses of deoxycorticosterone acetate and epinephrine alter this to the conditions found in eviscerated rats with intact adrenals. This could be mainly due to a circulatory effect of both hormones. – Eviscerated nephrectomised rats, constantly infused with glucose show a reproducable sensitivity-value for i. v. injected insulin. The value of this dose is over 0.05 U/kg insulin. Adrenalectomy momentarily causes an increase in the insulin sensitivity of the eviscerated animal. – The augmented insulin sensitivity following adrenalectomy is not clearly affected by deoxycorticosterone, but can be reduced by very high doses of prednisolone. The diaphragmatic glycogen values do not differ from those found in untreated animals. – Epinephrine completely abolishes the increased insulin sensitivity of the adrenalectomised eviscerated animal. This is probably due to a peripheral metabolic effect occurring mainly in the muscle tissue. The reduction in the diaphragmatic glycogen content suggests activation of the phosphorylase system with consequent inhibition of hexokinase. DHE abolishes the action of epinephrine on the hyper-sensitivity to insulin and on muscle glycogenolysis. Glucagon has no synergistic insulin action in the eviscerated nephrectomised rat, either in high or low doses. The insulin effect on the blood sugar of the highly insulin sensitive adrenalectomised eviscerated rat, is even diminished by high doses of glucagon. The mechanism of this peripheral insulin antagonistic action of glucagon occurs without glycogenolysis and has not yet been elucidated. The effect is however much slighter than that of epinephrine.