Effect of in utero exposure to hexachlorocyclohexane on the developing immune system of mice

Gestational exposure to 10 and 100 mg/kg body weight (m.b.w.) hexachlorocyclohexane throughout the gestation period was done to Swiss albino mice. HCH (alpha, beta and gamma isomers) residue analysis in pups showed a higher contamination in the lymphoid organs (Spleen, Thymus and Kidney) than liver in dose dependent manner. Immune functions of the offsprings of these dams along with the offsprings of vehicle treated or untreated control dams were assessed using selected parameters of both the cellular and humoral immune responses. The delayed hypersensitivity (DTH) response to sheep erythrocytes (SRBC) was significantly higher (p less than 0.01) in pups of the dams exposed to 10 mg/kg b.w. HCH and significantly impaired in pups of the dams exposed to 100 mg/kg m.b.w. HCH as compared to controls. Mitogenic responsiveness of the spleen cells in response to Concanavalin A (Con A) and Lipopolysaccharide (LPS) was almost two fold and eight fold higher respectively and antibody response to SRBC, as measured by plaque forming cells (PFC) assay was two fold higher (p less than 0.001) in pups exposed to 10 mg/kg HCH. However, 100 mg/kg m.b.w. HCH did not affect either mitogenic response or PFC response of the pups. The results, therefore, suggest that lower dose of HCH is capable of modulating the development and function of developing immune system possibly by modulating the functional organization of the T-cell populations.