Abstract:
Purpose: The notochord (Nt) is believed to play an important role in the development of axial organs. Abnormal development of the Nt has been considered to lead to a variety of congenital abnormalities. The aim of this study was to determine the nature and position of Nt malformation in rat embryos exposed to adriamycin (Ad). Materials and Methods: Time mated pregnant rats were injected daily with either Ad (2mg/kg, ip) or saline on days 6-9 of gestation. Their embryos were harvested on gestational day 13,5. Serial sections were analyzed histologically with routine Hematoxylene-eozin staining. Results: In normal embryos, the Nt was formed as a discrete axial structure in front of the neural tube and enveloped by perinotochordal mesenchyme. In the Ad-treated embryos, the Nt was branched and split into two or three parts at various levels, and become thinner and had vacuoles. Conclusion: Abnormal localization and malformations of the Nt may lead to a significant congenital malformation in associated organs.