FURTHER STUDIES ON THE HISTOCHEMISTRY OF GLUCOSE-6-PHOSPHATASE

Abstract

The tissues of the mouse were surveyed for glucose-6-phosphatase activity and the enzyme was found to be present only in the liver, kidney, small intestine, and rectum. The amount and distribution of the enzyme in the liver was not perceptibly altered in adrenalectomized animals or animals with alloxan diabetes. Some increase in activity was appreciated in animals starved for 72 and 96 hours. When sections were incubated in the presence of insulin or dextrose, no activation or inhibition was observed. Alloxan, on the other hand, did partially inhibit the enzyme. The action of fluoride, zinc, magnesium, and cyanide ions was also investigated. The possible role of the enzyme in the transport of glucose across cell membranes, involving phosphorylation and dephosphorylation, is discussed.