STUDIES ON THE CRYSTALLINE LENS

Abstract

LITTLE is known concerning the energetics of the lens. Although this organ does not have the specialized energy requirements of muscle or liver, it does require energy for active transfer of metabolites across the capsule and cell membranes, for the continual turnover of its structural elements, and for various other metabolic processes. Most of the energy for metabolic processes in other tissues is now thought to be made available as "high-energy phosphate." High-energy phosphate is energy contained in a particular type of unstable chemical bond involving phosphorus. The energy is transported from one metabolite to another chiefly by adenosinetriphosphate (ATP) and phosphocreatine. Thus, quantities of these substances present in a tissue would seem to give an indication of the energy available for cellular function. (A highly schematic diagram showing the relation of the production, utilization, and storage of high-energy phosphate is shown in Figure 1.) High-energy phosphate is probably formed