Amelioration of hydroxyurea-induced suppression of phagocytosis in human granulocytes by free radical scavengers.

The exposure of human circulatory white cells in vitro to 0.1-1-10 mol/l hydroxyurea (HU) for 20 h induced a progressive dose-dependent suppression of the phagocytic activity of granulocytes. The suppressing effect of 20 h exposure to 1 mol/l HU was used to examine the protection afforded by free radical scavengers against HU-induced cytotoxicity. It has been found that, in the suitable concentration of the protecting agent, a substantial protective effect of sodium benzoate, acetylosalicylic acid, alpha-tocopherol, ascorbic acid, catalase, peroxidase or superoxide dismutase can be achieved.