[Reproduction studies of carboplatin (II)--Intravenous administration to rats during the period of fetal organogenesis].

Carboplatin, an oncostatic drug, was administered intravenously to pregnant Crj: CD (Sprague-Dawley) rats from day 7 through 17 of gestation at dose levels of 1, 2 and 4 mg/kg/day. The summarized results obtained are as follows: 1. Carboplatin 4 mg/kg suppressed the maternal body weight gains from day 13 through 20 of gestation. 2. Uterine weights were reduced in F0 dams at term at carboplatin 4 mg/kg. 3. Carboplatin 4 mg/kg brought the inhibition of fetal growth accompanied by the lowered values in fetal weights, crown-rump distances and tail lengths. Furthermore, the elevated incidences of unossified 5th and 6th sternum , as well as retarded ossification of sacrococcygeal vertebrae were also noted in this dose level. 4. The birth rate was reduced in neonates (F1) at carboplatin 4 mg/kg. 5. Body weight gains in male F1 rats were suppressed at carboplatin 4 mg/kg from 4 to 8 weeks of age. 6. Carboplatin 4 mg/kg decreased the brain weights on an absolute basis in female F1 rats, but failed to affect their postnatal differentiations, early behavioral developments, learning ability, motor activity or emotional development. 7. Reproductive ability in F1 rats of both sexes were not affected by carboplatin. 8. Influences on prenatal development were not apparently observed for F2 fetuses derived from F1 rats whose dams had ever received carboplatin during the organogenetic period. Based on these results, the no-effect dose level of carboplatin under the present experimental condition was estimated to be 2 mg/kg/day against dams and their offspring.