Lysosomal hydrolases in tears and the lacrimal gland: effect of acetylsalicylic acid on the release from the lacrimal gland.

Free and lysosomal activities of 10 acid hydrolases have been determined in human lacrimal gland tissue. The enzyme activities appeared mainly in the lysosomal fraction, and the proportions correspond very well with those found in the tear fluid. Acetylsalicylic acid at blood levelsof about 1 mM produced a significant lowering of the beta-hexosaminidase concentration in tears. It is suggested that acetylsalicylic acid may have a stabilizing effect on lacrimal lysosomes, resulting in a diminished release of lysosomal enzyme from the lacrimal gland.