Effect of chlorhexidine on the release of lysosomal enzymes from cultured macrophages

Exposure of rat's peritoneal macrophages to chlorhexidine at concentrations up to 0.01 per cent resulted in the release of lysosomal enzymes, e.g. chloride-dependent arginine aminopeptidase and beta-D-glucuronidase into the medium from resting cells. The activity of extracellular lactate dehydrogenase increased up to the concentration of 0.01% and then decreased with increasing chlorhexidine concentration. This could indicate a certain type of "mummifying" of the cells and/or their membranes. The incorporation of trypan blue was found in all cells after a rinse with 0.05 per cent or higher concentrations of chlorhexidine. The direct effect of chlorhexidine on these enzyme activities showed a slight activation of beta-D-glucuronidase and lactate dehydrogenase, but an inhibition of arginine aminopeptidase. Also the binding of chlorhexidine to cells was found. Low chlorhexidine concentrations caused an additional enzyme release from phagocytizing cells.