You are here:
IMMUNOTOXICITY OF INDIVIDUAL ORGANOTIN COMPOUNDS IN SPRAGUE-DAWLEY RATS
Citation:
DEWITT, J., C. B. COPELAND, AND R. W. LUEBKE. IMMUNOTOXICITY OF INDIVIDUAL ORGANOTIN COMPOUNDS IN SPRAGUE-DAWLEY RATS. Presented at Annual Society for Risk Analysis Meeting 2005, Orlando, FL, December 04 - 07, 2005.
Description:
Organotins, used as stabilizers for polyvinyl chloride pipe, leach into drinking water from supply pipes and may cause multisystem toxicity, including immunotoxicity. We assessed immune function in Sprague-Dawley rats exposed to dibutyltin dichloride (DBTC) or dimethyltin dichloride (DMTC). Adult males and females drank water containing 0, 10, or 25 mg DBTC/L in 0.5% Alkamuls or 0, 20, or 40 mg DMTC/L for 28 days. Pregnant dams drank water containing 0, 10, or 25 mg DBTC/L from gestational day six to postnatal day 21 (PND21); subgroups of offspring were additionally exposed via direct gavage starting at PND3 to 0, 1.0, or 2.5 mg DBTC/kg/dose, 3X/week for ten doses. Adult water consumption was measured 2X/week and body weight (BW) was recorded at least weekly. Functional assays included delayed-type hypersensitivity (DTH), primary and secondary antibody responses, and natural killer (NK) cell activity. Water consumption was decreased at high doses relative to controls in all studies. BW, immune organ weights, DTH response, and NK cell activity were not affected by adult exposure. BW gain of offspring in the direct 25 mg DBTC/L group was decreased relative to controls. Antibody responses in males exposed to DBTC as adults differed in two replicate exposures: IgG was elevated at the highest dose in one replicate whereas IgM was suppressed in the second. No changes were observed in DMTC-exposed adults. In DBTC-exposed offspring, IgM was suppressed in females (maternal-gavage exposure) and IgG was elevated in males (maternal only exposure). In adults and offspring, these effects on antibody production occurred at 25 mg DBTC/L, a concentration close to one million times higher than DBTC levels reported in drinking water. Our data suggest that neither DBTC nor DMTC are likely to be associated with immunotoxicity at concentrations found in drinking water supplies. This abstract does not reflect EPA policy and was supported by UNC/EPA Cooperative Training Agreement CT829472.