Stimulation of aryl sulfatase in rat peritoneal macrophages exposed to bone in vitro

Rat peritoneal macrophages elicited by injection of thioglycollate were cultured in the absence and presence of non-vital, milled rat bone or latex beads. After 0, 48, 96, and 144 hours exposure to these substances, the levels of aryl sulfatase B were determined. Cells exposed to bone demonstrated a significant (p less than .001) time-dependent increase in the specific activity of aryl sulfatase B. After 144 hours the specific activity of aryl sulfatase in cells exposed to bone was 20 fold higher than that in the 144 hour controls. There were no significant differences in the levels of aryl sulfatase B in controls over time, nor were the levels of enzyme in those exposed to latex beads difference from controls. We conclude that the specific activity of aryl sulfatase B increases when macrophages resorb bone and suggest that this enzyme could be used as a marker or index for bone resportion.