INFLUENCE OF EXPERIMENTAL KIDNEY DAMAGE ON HISTOCHEMICALLY DEMONSTRABLE LIPASE ACTIVITY IN THE RAT. COMPARISON WITH ALKALINE PHOSPHATASE ACTIVITY.

Lipase activity was found in the cytoplasm of the proximal convoluted tubules in tissue sections of rat, rabbit, dog, mouse, hamster, and guinea pig, stained according to Gomori's method. Uranium and mercury poisoning do not inactivate the enzyme in necrotic cells of the proximal convoluted tubules. Its activity diminished in the atrophic and regenerating cells of the kidneys of rats, surviving the acute phase of the intoxication. In the acute stage of choline deficiency marked reduction in enzymatic activity was seen in the necrotic tubules, and in the atrophied and regenerating tubules in the subacute stage. Lipase activity was markedly diminished in hydronephrotic kidneys 10 to 12 days after ligation of the ureter. In sections stained for alkaline phosphatase activity nearly identical alterations were found. Experimental damage influences both histochemically demonstrable enzymes in a similar manner.