EVALUATION OF HEMATOLOGICAL AND IMMUNOLOGICAL PARAMETERS IN MICE EXPOSED TO SUBLETHAL AND SUBCHRONIC DOSES OF DIMETHOATE

Effects of sublethal and subchronic doses of dimethoate (DM), an organophosphorus pesticide, have been studied on hematological and immunological parameters in mice. The results revealed that DM-treated mice showed significant increase in red blood cells (RBC), white blood cells, percent monocytes, and percent basophils, whereas the percent neutrophils was significantly decreased.The antibody titres were higher on day 4 postantigen(sheep RBC/bovine serum albumin [BSA]) inoculation, but suppressed on day 7 and 11 postantigen inoculation in DM-treated mice. However, the three cell-mediated immune parameters-leukocyte migration inhibition (LMI), leukocyte adherence inhibition (LAI), and nitroblue tetrazolium (NBT) reduction-were invariably depressed in DM-treated BSA-immunized mice, whereas the percent LMI and LAI were lower and NBT was higher in the DM-treated SRBC-immunized mice. Our results show that exposure to DM suppresses humoral and cell-mediated immune response, but its effect on macrophage function varies with the immunizing antigen.