Teratogenic effects of bilirubin--a study using chick embryotoxicity screening test (CHEST)

Using the Chick Embrotoxicity Screening Test (CHEST), two samples of bilirubin of different commercial origin were tested on 2, 3 and 4- day old chick embryos. Water soluble Bilirubin Lachema (containing 20 mg albumin per 1 ml) had no teratogenic effect. On the opposite, Bilirubin Merck (containing 8 mg albumin per 1 ml) manifested an apparent teratogenic potential when single doses 0.2 and 0.6 micrograms were administered intraamniotically on day 4. Dose-dependent malformations of brain and eyes, cleft beak and reduction deformities of limbs were observed. No such effects could be produced by administration of Bilirubin Merck on either day 2 and 3. A tentative explanation of the difference between teratogenic properties of Merck and Lachema bilirubin preparations may be sougth in the different proportion of the free and albumin bound fractions.