Lysosomal enzyme activities in cultured trabecular-meshwork cells

We examined the lysosomal enzyme levels in cultured trabecular meshwork cells. Histochemical studies revealed that bovine trabecular meshwork cells stained prominently for acid lipase, acid phosphatase, and acid esterase activities. Following phagocytic challenges, such as incubations with latex microspheres or zymosan particles, lysosomal enzyme staining was visibly enhanced. The uptake of foreign particles by trabecular-meshwork cells was evident. Data from biochemical assays for acid lipase, cholesteryl esterase, and acid esterase confirmed the histochemical findings. These results indicate that trabecular meshwork cells are actively phagocytic in culture and that lysosomal enzyme levels in these cells may be modulated by phagocytic challenge.