Embryonic abnormalities in hamsters following intrauterine injection of 6‐aminonicotinamide

Abstract

Abstract Hamster embryos were injected intraamniotically (ia) with 6‐aminonicotinamide (6‐AN) on gestation day 7, 8, or 9 and examined near term. Control treated embryos received 5 μl of water, a needle puncture without injection, or no treatment, and had low rates of resorption and malformation. 6‐AN injected ia produced offspring with multiple defects including exencephaly, cleft palate, anophthalmia, micrognathia, and hydrocephalus. In contrast to day‐8 and ‐9 embryos, which responded to 5‐μg doses of 6‐AN, day‐7 embryos required 50–100 μg before exhibiting abnormalities.