Effects of thiabendazole on the mouse limb-bud organ and cell in culture.

In relation to the mouse limb malformations caused by thiabendazole (TBZ), we tested the teratogenicity of TBZ in a mouse limb bud culture system. TBZ interfered with the development of the explants under our experimental conditions. Comparison of the protein and DNA content of the forelimbs of TBZ-treated and control animals showed that TBZ tended to reduce the amounts of DNA more than those of protein. Studies on the biosynthesis of proteoglycan as an index of limb chondrogenesis demonstrated that TBZ impaired its biosynthesis in the limb bud cell system. These results may indicate that TBZ directly causes the abnormalities in mouse limb development. The site and mechanism of teratogenic action of TBZ are also discussed.