Twenty‐nine pregnancies were obtained in 21 female bonnet monkeys. The females were housed individually and were mated for a 2‐h period, usually 2 days before midcycle. The day of mating was designated as day o of pregnancy. After pregnancy was confirmed by rectal palpation the animals each received 5, 10, or 30 mg/kg thalidomide orally, either as single doses on days 24, 25, 26, 27, 28, or 29 or once per day on days 25–27 or 41–44. With 5 and 10 mg/kg only malformations of the forelimbs were observed, characterized by total absence (amelia) or partial absence (meromelia) of the free limb. In all cases the malformations were more severe on the left side than the right. No craniocaudal developmental gradient was noted with 10 mg/kg. With 30 mg/kg forelimb and hindlimb malformations occurred, although the hindlimb malformations were mild and consisted essentially of either bowing or partial absence of the femur. A craniocaudal developmental gradient was evident with 30 mg/kg. Treatment during the time of palate closure (days 41–44) did not affect normal palate development. Absence and/or malformations of the uterus, ovaries, kidney, heart, brain, spleen, and umbilical arteries also occurred.
ASJC Scopus subject areas
- Developmental Biology
- Health, Toxicology and Mutagenesis