Electrophoretic Study of Proteins from Normal and Irradiated Lenses of the Rabbit

Abstract

in the lens epithelium which antedated any clinical evidence of cataract. These changes became more marked with increased exposure. Cells appeared which were several times as large as the normal epithelial cell. The cytoplasm was often vacuolated. The nuclei of such cells frequently appeared enlarged or fragmented, but little or no genuine mitosis was observed. Cogan and Donaldson stated that these injured cells appeared unable to form normal fibers but remained globular. They suggested that the connection between these cells and the opacification of the lens cortex might be that the cells degenerate, liberating their intracellular enzymes, thus causing lysis of the lens cortex. Years earlier Clapp (2) observed that a crushed lens under aseptic conditions underwent autolysis. This study led him to suggest that the proteolytic enzymes of the lens played an important part in the formation of a certain type of cataract, and that after injury to the lenticular cell some of the protein hydrolyzed and diffused into the aqueous humor. Such a reaction would undoubtedly alter the number of protein fractions present as well as their physical and chemical properties. The number of protein fractions present in the lens is not known with certainty. Hesselvik (3), by means of electrophoretic methods, was able to demonstrate the presence of at least two protein fractions in an aqueous extract of bovine lenses. The