Acid and alkaline phosphatases in the kidney of a few fishes.

The localization of acid and alkaline phosphatases in the kidney of Cirrhinus reba, Ompak bimaculatus and Labeo gonius has been studied. In all these fishes, the enzymes are found in the proximal tubule. The activity of alkaline phosphatase is more stronger than acid phosphatase. The renal capsule, distal tubule, collecting tubule and interstitial hematopoietec tissue are all phosphatase negative. The activity is more stronger in the first proximal tubule than in the second tubule. It is probable that acid phosphatase is associated with the intracellular digestion of the macromolecules absorbed and alkaline phosphatase with the absorption of glucose from the tubular lumen.