CALCIUM DISTRIBUTION IN THE HUMAN EYE LENS

The distribution of calcium in the human eye lens was investigated usi ng the oxalate-pyroantimonate technique. In epithelial cells and super ficial cortical fibers calcium is sequestered and tightly bound to pro teins in the endoplasmic reticulum, nuclear envelope, Golgi cisterns a nd mitochondria. In intermediate fibers these cell organelles are brok en down and the liberated calcium is ionically bound to the phospholip ids at the extracellular side of the fiber-limiting membrane. It is ar gued that calcium is probably additionally bound to beta-crystallin. T his site-specific variation in calcium storage might explain the deepe r cortical localization of early focal dot opacities and retrodots.