Glucose-6-phosphatase activity in normal, pre-cancerous, and neoplastic tissues.

Abstract

Summary The glucose-6-phosphatase (G-6-Pase) activity was investigated in normal and precancerous tissues, in transplanted and induced tumors, and in the liver of tumor-bearing animals. 1.Highly active G-6-Pase was found only in those normal organs which are able to release glucose into the blood stream (liver, kidney). Other organs (small intestine, brain, lung, spleen, muscle) contained only low or negligible activities. 2.The liver G-6-Pase activity of mice bearing E 0771 adenocarcinoma was significantly lower than the activity of normal mouse liver. No difference was found between normal rat liver and the liver of rats bearing transplanted Novikoff hepatoma. 3.Homogenates of Sarcoma 37, E 0771 transplantable adenocarcinoma, 6C3HED lymphosarcoma, and Novikoff hepatoma possessed no G-6-Pase activity. It has not been possible to demonstrate a G-6-Pase inhibitor in any of these neoplastic tissues. The G-6-Pase activity of liver decreased progressively during carcinogenesis produced by 4-dimethylaminazobenzene and was almost completely absent in the hepatomas. 4.The pathways of glucose-6-phosphate utilization in hepatoma were discussed.