Respiration of Isolated Liver and Kidney Tissues from Adrenalectomized Rats

Abstract

After adrenalectomy the basal metabolism of rats is depressed. It is possible that the depression is the result of metabolic disturbance in certain special organs or tissues rather than a general metabolic weakness. The oxygen consumption of brain tissue is not influenced by removal of the adrenal cortex, nor is that of skeletal muscle. The hepatic and renal malfunction resulting after ad-renalectomy suggests that energy reactions in these tissues may be altered. The rate of oxygen consumption of liver and kidney slices from rats showing marked symptoms of insufficiency (about 9 days after operation) is significantly depressed. The mean values together with the standard error of the mean are shown in Table I. The tissues were studied in Ringer's solution with phosphate buffer at pH 7.3 with no added substrate. The depression is not due to the starvation resulting from the marked anorexia which is present since a group of starved normal rats showed values very similar to those of the well-fed normals. The rate of oxygen consumption of liver slices from normal rats is considerably increased when pyruvic acid and succinic acid are added to the medium, indicating an active oxidation of these metabolites. It is now recognized that these substances are important intermediary metabolites in carbohydrate oxidation. The data presented in Table II show that after adrenalectomy the rate of oxidation of these substances is slower. Pyruvate oxidation is influenced to a greater extent than that of succinic acid (40% depression with pyruvate as compared with 30% in the case of succinate). The effect of adding dextrose to the medium is the same after adrenalectomy as before. It is concluded that oxidative systems are impaired by a deficiency of the adrenal cortex hormones, but the weakening appears to be general in nature rather than restricted to some one component of the oxidation chain.