Teratogenic effects of benzo[a]pyrene in developing chick embryo.

The effect of benzo[a]pyrene (BP), an established carcinogen, on developing chick embryos was investigated. The embryos were exposed in different stages of development to various doses of BP via the yolk sac route. This resulted in retarded growth, as reflected by lower embryonic body weight, reduced crown-rump length and bill length. Abnormal survivors showed remarkably twisted legs with shortening of the bones, abdominal oedema, haematomas, blisters and a short neck. These findings suggest that BP is a teratogen when injected via this route, and the 'oedema syndrome' is a possible mechanism causing teratogenic effects in developing chick embryos when treated with BP.