Activity of glucose-6-phosphatase in regenerating tubular epithelium in rat kidney after necrosis induced with mercuric chloride: a light and electronmicroscopical study.

The activity of glucose-6-phosphatase was investigated in the renal proximal tubules of male albino rats after necrosis induced with mercuric chloride. Between the 3rd and 14th days an active zone could be observed in the inner cortex, which in the control animals was inactive. As regeneration progressed, the number of regenerating active tubules in the cortex increased, and in the 4th week activity approached that of the controls. Ultrastructurally, the enzyme was localized in the endoplasmic reticulum and nuclear envelope and sometimes even in necrotic cells. It appeared again in the regenerating cells on the 4th day. Our histochemical results complement the published biochemical results on the analysis of tissue homogenates localizing the changes of enzyme activity. From this comparison we conclude that glucose-6-phosphatase may take part in either glucose degradation or gluconeogenesis, but whereas gluconeogenesis also occurs in the first part of the proximal tubules in the normal kidney, the enzyme may play a role in glucose consumption only under pathological conditions.