Forelimb malformation in rats caused by cyclophosphamide

A single dose of cyclophosphamide (20 mg/kg) was administered to female rats on Day 12 of gestation. Fetuses were collected at 24-h intervals from gestation Day 18 to 20. Gross malformations of the forelimb were observed, notably micromelia, oligodactyly, brachydactyly and adactyly. Specimens stained with Alizarin red-s and Alcian blue revealed postaxial skeletal deformities. Chronological histochemical investigations revealed delay in the ossification of the radius and completely unossified ulna; the end results showed the ulna to be more affected than the radius.