||Immune Function in Adult C57BL/6J Mice Following Exposure to Urethan Pre- or Postnatally.
Luebke, R. W. ;
Riddle, M. M. ;
Rogers, R. R. ;
Rowe, D. G. ;
Garner, R. J. ;
||Health Effects Research Lab., Research Triangle Park, NC. ;Northrop Services, Inc., Research Triangle Park, NC.
Laboratory animals ;
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Administration of urethan (URE or ethyl carbamate) to mice results in the development of a variety of tumors, and, in certain strains of mice, marked supression of the immune response. Perinatal exposure of mice to URE has been found to result in increased tumor induction compared to exposure of adult animals. In the present study, the effects of perinatal exposure to URE on the development of immunocompetence was investigated. Pregnant mice were injected with total doses of either 0.5 or 1.0 mg URE/g of body weight over days 7-16 of gestation or pups of nontreated dams were administered a total dose of 2.0 mg URE/g of body weight over postpartum days 5-14. Postnatal exposure to URE suppressed NK (natural killer) cell activity but left intact other measured parameters of the host defense system. Prenatal exposure, on the other hand, resulted in elevated leukocyte counts and a trend toward increased spleen and thymus size in offspring of treated mothers.