Tumor cytotoxicity of peritoneal macrophages induced by OK-432

In the present study we investigated the enhancement of cytotoxicity of per itonea] macrophages induced by OK-432. Rats received an i.p. injection of O K-432 at doses of 0.1, 0.5 or 1.0 KE/rat. Two days later, rats were sacrifi ced and peritoneal macrophages were isolated. Then the number of macrophage s was counted, and the macrophages were analyzed for their lactic dehydroge nase (LDH) activity, acid phosphatase (ACP) activity, phagocytic activity, secretion of nitric oxide (NO) and cytotoxicity. The number of peritoneal m acrophages, the activity of LDH and ACP, phagocytic activity, NO secretion, and cytotoxicity were increased with the increasing doses of OK-432. The r esults suggested that OK-432 enhanced tumor cytotoxicity of peritoneal macr ophages by three steps. The first step is to attract a great number of macr ophages into the peritonea[ cavity. The second step is to enhance the phago cytic and eliminating function of these macrophages. The last step is to in crease the non-contact cytotoxicity of macrophages. [(C) 2001 Lippincott Wi lliams & Wilkins.].