Ultrastructural study on the enzymes in the pancreatic B-cells of the rat.

The ultrastructural localization of AcPase, AlkPase, ATPase, TPPase, NDPase and G-6-Pase in rat pancreatic B-cells is studied. The plasmolemma is reactive to AlkPase, ATPase, and NDPase. The concave part of the Golgi complex and the lysosomes show AcPase and TPPase activity. In the halo of some beta-granules located near to the Golgi area the AcPase activity is also present. The cisterns of the endoplasmic reticulum are positive for G-6-Pase. So each of the phosphatases has a well expressed ultrastructural localization. It is assumed that this enzyme specificity is connected with the specific organelle's metabolism. Some considerations are made for the possible role of each enzyme in the B-cell physiology.