Effect of ascorbic acid on arylsulfatase A and B activities in human chondrocyte cultures

Cultured normal human articular cartilage chondrocytes exhibited decreasing levels of arylsulfatase A and B activities when grown in the presence of increasing levels of ascorbic acid (0 to 90 mug/ml) in the media. That this was not a general effect on all lysosomal enzymes was supported by the increase in acid phosphatase activity and no change in beta-glucuronidase activity observed with increasing levels of vitamin C under identical culture conditions. No decrease in either arylsulfatase activity was observed when ascorbic acid was replaced by ascorbate-2-sulfate. Ascorbic acid did not inhibit either arylsulfatase activity when added directly to the assay mixture. These data, combined with results of mixing experiments, suggest that the effect of vitamin C is mediated through cellular factors produced in response to its inclusion in the growth media.