Histopathological changes associated with exposure of male mice to pyrethroid pesticide (lambda- cyhalothrin)

The male albino rats were administered to sub-lethal concentrations 1/10 LD_50 = 9.5 mg LCT/kg b. wt., 1/40 LD_50 = 2.37 mg LCT/kg b. wt., and acceptable daily intake (ADI) = 0.005 mg LCT/kg b. wt. orally twice a week for 30, 60, and 90 consecutive days. Histopathological examination revealed that, tissues were normal in the control group, but in treated group liver showed congestion of hepatic blood vessels, vascular degeneration with necrosis of hepatic cells. The cells within the group oriented toward the base membrane. The hepatic cells showed polymorphism in its shape and size and the nucleus were enlarged with typical or a typical meiotic activities (hepatic carcinoma). Pathological finding in kidney showed congestion of renal blood vessels in both cortex and medulla together with perivascular edema, degeneration and coagulative necrosis and cystic dilation. Pathological finding in spleen showed hyperplasia of the lymphocytes of the white pulp with infiltration of the red pulp with lymphocytes, congestion of splenic sinusoids and hemorrhages with depletion of lymphocytes in white pulp. Pathological finding in brain showed congestion of meningeal blood vessels, lymphocytic aggregation, degenerative changes of the nerve fibers and fragmentation and necrotic changes of some neurons. Generally histopathological examination revealed vascular congestion, hydrophic degeneration and leukocyte infiltration in the affected organs at the initial stages. At the terminal stage of toxics, coagulative necrosis, aggregation, odema, and carcinoid tumors of liver. The degree of changes was obviously at high dose (treatment 1/10 LD_50 was more effective in changes than 1/40 LD_50 treatment), it was not able to observe any significant changes at low dose (ADI), it means that (LCT) caused dose dependent, and induces histological aspects of liver which was the most affected organ.