Transplacental Induction of Tumors in Sprague-Dawley Rats With Crude Cycad Material2

Abstract

Tumors have been induced transplacentally by crude cycad meal containing 3% cycasin fed to rats at various periods of gestation. The over-all relative incidence of neoplasia in the offspring was 18.5%. The interval necessary for tumor production was essentially the same as that previously reported in immature and adult rats fed crude cycad material, cycasin, or the aglycone of cycasin. Frequent sites of neoplasia were brain and jejunum, organs rarely involved by tumors in earlier feeding experiments in rats. No teratogenic effects were found among the rats dying during the immediate postpartum period or later in life. The death rate among newborn rats exposed in utero was 42%. Hypoplastic mammary glands and a decreased suckling stimulus normally necessary to maintain lactation appeared to be important causes for the early deaths.