Embryogenesis of adriamycin-induced hindgut atresia in rats.

It was proposed that the pathogenesis of multiple intestinal atresias (MIA) in human fetuses is a consequence of malformative processes of the gastrointestinal tract rather than an ischemic process. Recently, MIA has been described in adriamycin-exposed rat fetuses. The aim of this study was to describe the embryogenesis of hindgut atresia (HA) in the adriamycin animal model. Timed-pregnant Sprague-Dawley rats were injected with adriamycin on days 6-9 of gestation. Embryos were removed on different gestational days during organogenesis and histologic sections were examined and compared with control specimens. In experimental embryos, HA was seen on day 13; however, the lumen was patent on day 12. HA was associated with abnormal vascular anatomy that was obvious on days 12 and 13. It is concluded that HA in adriamycin-exposed embryos occurs at the beginning of organogenesis. Although it was associated with an obvious vascular anomaly, further studies are required to find out whether it is ischemic in origin.