Rates of Oxidation of Different Substrates in the Frog's Liver

Abstract

IN the course of preliminary studies in an investigation regarding the mechanism of the regulation by hormones of enzymic processes, we have carried out determinations of the respiratory quotient (RQ) of the liver tissue with homogeneous material from the frog (Rana temporaria) in the summer state. For each specimen a determination of respiratory quotient was performed on slices by a modification¹ of the method of Meyerhof and Schmitt. The values obtained varied between 0·70 and 1·00. When the values of the oxygen consumption per mgm. fresh weight were correlated with the corresponding values of the respiratory quotient, it was found that high values of the latter were accompanied by low oxygen consumptions and vice versa. It follows that different substrates occurring in the liver of the frog are oxidized at different rates.