Effect of endosulfan on peripheral sheep leukocytes in vitro

The immunotoxic and genotoxic effect of endosulfan, an organochlorine insec ticide, on sheep peripheral blood leukocytes was examined in in vitro condi tions. The immunotoxic effect was evaluated by assays of the metabolic acti vity of phagocytes and assays for lymphocyte activation - the leucocyte mig ration-inhibition assay (LMIA) and lympho-proliferation. The significant in hibitory effect of endosulfan on metabolic activity of peripheral blood pha gocytes was registered at the actual concentrations of 10(-3)- 10(-4)M. At 10(-3)M the migration of leukocytes was inhibited, both in activated and no n-activated with phytohemagglutinin (PHA) leukocyte suspensions (p<0.01) in LMIA. This indicated the direct cytotoxic effect of endosulfan on the poly morphonuclears and monocytes of which the intensity of migration is an indi cator of lymphocyte activation with mitogen. At the concentration of 10(-4) M an immunotoxic effect, ie significant decrease of lymphocyte activation w ith mitogen was recorded in LMIA. Lympho-proliferation test showed the sign ificant inhibition of proliferation for PHA-stimulated lymphocytes at 10(-3 )M and 10(-4)M. Micronucleus assay evaluated the genotoxic potential of end osulfan. Higher concentrations of insecticide (10(-5)M. 10(-6)M) resulted i n a significant dose dependent increase in the number of micronuclei.