Prevention of etretinate-induced craniofacial malformations by vitamin B6 in the rat.

The preventive effect of vitamin B6 on etretinate-induced malformations in pregnant Sprague-Dawley rats was studied. The etretinate-induced malformation was produced by intraperitoneal administration of 10 mg/kg etretinate at embryonal day 8.5. Vitamin B6 was administered as intramuscular injections at embryonal day 7.5 and 8.5. Vitamin B6 reduced the number and severity of facial clefts, micrognatia, meningocele, microtia and blood vessel anomalies. It is suggested that vitamin B6 induces suppressive effects on etretinate-induced teratogenesis when administered before or at the same time as the teratogen.