Evaluation of the Immunotoxicity of {eta}-Hexachlorocyclohexane ({eta}-HCH)

Evaluation of the Immunotoxicity of-Hexachlorocyclohexane -HCH).CORNACOFF, J. B., LAUER, L. D., HOUSE, R. V., TUCKER, A. N.,THURMOND, L. M., VOS, J. G., WORKING, P. K., AND DEAN, J. H.Fundam Appl. Toxicol. 11,293–299.0-HCH, an isomeric contaminantformed during the manufacture of the insecticide lindane, isa persistent environmental and food chain pollutant which hasbeen reported to exhibit estrogenic activity in rodents andin fish. To investigate potential toxic effects on the reproductiveand immune systems, -HCH was fed to female B6C3F1 mice for 30days. Mice exposed to 0, 100, or 300 mgo-HCH/kgofdiet were evaluatedfor changes in ovarian and uterine histology, body weight, lymphoidorgan weight and histology, splenic cellularity, antigen-specificIgM and IgG plaque-forming cells (PFQ, proliferative responsesto mitogens, natural killer (NK) cell activity, and inductionof cytolytic T lymphocytes. The ovaries and endometrial epitheliumexhibited normal architecture. No alterations were observedin body weight, lymphoid organ weight and histology, or spleniccellularity whereas significant changes were found in severalimmune functions at the 300 mg/kg dose. Proliferation of splenocytesto the mitogens LPS, PHA, and Con A was decreased by 39,43,and 57%, respectively. T-lymphocyte-mediated cytolysis of tumortargets was decreased by 25% with a concurrent reduction of45% in NK activity. There was no significant reduction in thenumber of IgM or IgG PFC in exposed animals. These data indicatethat -HCH causes nonestrogenic immune function changes in theadult mouse without gross changes in lymphoid organ weight,histology, or cellularity.