Acid phosphatase localization in the equatorial region of human lenses.

Localization of acid phosphatase activity is described in equatorial segments of four human cataractous lenses, including one lens with equatorial cortical cataract, and three lenses with no significant equatorial opacities. The lenses were removed surgically with a cryoprobe. Enzyme reaction product was confined mostly to epithelial and cortical Golgi complexes and dense bodies, and to cortical smooth endoplasmic reticulum (SER). It also was located in small cortical vacuolar cysts in the lens with equatorial cataract, and intercellularly in a single lens which was devoid of equatorial opacity. In the latter case, intercellular activity was confined mostly to areas showing minimal pathological modification. Evidence is presented that the cortical SER represented GERL. The hypothesis is made that intercellular acid hydrolase activity might play a role in the early stages of human senile cortical cataract development. However, it is recognized that confirmation of this hypothesis will require additional studies involving comparison of both cataractous and normal lenses of various ages, which have been removed by a careful procedure which minimizes the lysis of lens cells.