EFFECT OF CORTISONE ON THE INTRACELLULAR DISTRIBUTION OF PHOSPHATASES AND RIBONUCLEASES IN RAT LIVER

Abstract

The effect of cortisone acetate administration on the mitochondrial population and intracellular distribution of phosphatases and ribonucleases was investigated. Cortisone acetate was administrated at a dosage of 25 mgm. per 100 gm. body weight, daily, during five days and sacrificed on the sixth day. The livers of these animals were removed and homogenized in 0.25 M sucrose and subjected to differential centrifugation to prepare nuclear, mitochondrial, microsomal, and supernatant fractions. Nuclear and mitochondrial counts were made for each homogenate prepared. From these the number of mitochondria per average cell was computed. The intracellular distribution of RNAase and PO4ase activities was determined and expressed per average cell and per liver/body weight ratio. The activity of the mitochondrial fraction was also expressed per average mitochondrion. Results of this investigation showed that cortisone lowered the number of large granules per liver cell without influencing the acid PO4ase and acid and alkaline RNAase activities per cell. This suggested that mitochondria isolated from cortisone treated rats possessed abnormally high acid PO4ase and RNAase activities or/and that the remaining population of granules was different from the one in liver cells of untreated animals. The investigation of alkaline phosphatase revealed that cortisone increased the Mg++ sensitive alkaline PO4ase localized in the supernatant fluid without influencing the Mg++ insensitive enzyme.