[The biotransformation and toxicity of xenobiotics in the chick embryo. 1. The embryonated hen's egg as an in vivo model and sodium salicylate as substrate].

After application of sodium salicylate (1) on d 6 of incubation into the yolk sac of the embryonated hen's egg (Gallus domesticus) 3 compounds were detected in the allantois fluid (AF) dependent on embryo age. Compounds were isolated and identified (M.p., MS, TLC, HPLC) as salicylic acid (1a), o-pyrocatechuic acid (2,3-dihydroxy benzoic acid; 2) and gentisic acid (2,5-dihydroxy benzoic acid; 3), respectively. 1a, 2 and 3 are eliminated from chick embryo in both the free and the glucuronidated form. The toxicity of 1 which was inoculated on d 6 of incubation increased between d 10 and 18 of the embryo age (LD50 318 and 281 mg X kg-1 egg weight, respectively, parallel to the rise of building and excretion of dihydroxy benzoic acid metabolites (increase from 0 to 78.5% of total metabolites).