Congenital defects in the offspring of male XXXX treated with ethylnitrosourea.

@entity7045 @entity19 @entity853 @entity600 @entity2419
Daily doses of ENU (25-100 mg/kg) were injected intraperitoneally into ICR strain male @entity19 for 5 days. The males were mated to untreated virgin females of the same strain on days 1-16 and 64-80 after the last dose. Copulations during these periods involve, respectively, treated postmeiotic cells and spermatogonial stem cells. The uterine contents were examined on day 18 of pregnancy for evidence of dominant lethal effects. The fetuses were examined for external and @entity853 . ENU treatment of either postmeiotic cells or spermatogonial stem cells caused dose-dependent significant increases in the incidence of abnormal fetuses over the control level. The induction rate per live fetus per unit dose in mg/kg by treating spermatogonial stem cells was estimated to be 1.0 X 10(-4), which is 3-fold lower than the rate previously estimated for the same endpoint at the same germ cell stage with @entity7045 . @entity2419 was the most frequent external abnormality in the ENU-treated and the control series. Malformed vertebrae was the most frequent @entity853 in the treated series. Rib fusion was the only @entity600 seen in the control series. Dominant lethals were clearly induced when germ cells were treated as postmeiotic cells.
