Suppression of natural cytotoxic cell and macrophage phagocytic function in oyster toadfish exposed to 7,12-dimethylbenz[a]anthracene

Studies were undertaken to determine the effects of the chemical carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) on the function of oyster toadfish peritoneal non-specific cytotoxic cells (NCC) and macrophages. The functioning of these two cell populations was assessed in terms of their ability to lyse cultured tumour target cells and to phagocytose yeast cells, respectively. Following intraperitoneal (i.p.) injection of 0, 1, 10, 50 and 100 mg DMBA/kg body weight, macrophage activity was suppressed in essentially a linear fashion, whereas NCC activity was virtually obliterated at all doses of DMBA administered. Thus, non-specific cytotoxicity in oyster toadfish has been shown to be substantially more sensitive to DMBA than non-specific phagocytosis.