Acid phosphatase localization in accumulated membranous organelles of optic nerve axons following acute elevation of intraocular pressure.

Acid phosphatase localization in accumulated membranous organelles of optic nerve axons of guinea pigs following acute elevation of intraocular pressure (IOP) was determined, employing light and electron microscopic enzymic cytochemistry with beta-glycerophosphate as a substrate. Positive reaction products appeared to accumulate in the region of the lamina cribrosa, as revealed with light microscopic enzyme cytochemistry. Electron microscopic enzyme cytochemistry also demonstrated that such reaction products mainly localized on multivesicular or multilamellar bodies and myelin-like structures in the unmyelinated optic nerve axons. Following an acutely elevated IOP, retrograde-moving membranous organelles in the optic nerve axons were found to contain AcPase, suggesting that these organelles could be degraded in the axons through the lysosomal pathway.