Aortic aneurysm associated with cardiac defects in theophylline stimulated chick embryos

Abstract

Theophylline (1 ml 0.02 M in 0.15 M saline) was administered to embryonic chicks (Hamburger‐Hamilton developmental stages 24–27). The drug was topically applied to the surface of the chorioallantoic membrane in the vicinity of the embryonic heart. At necropsy, 63% (44/70) of the theophylline‐exposed embryos demonstrated an aneurysm in the ascending aorta. Among the cases exhibiting aortic aneurysm, 48% (21/44) of the embryos demonstrated ventricular septal defects. Four cases of truncus arteriosus were also observed. The morphogenesis and mechanism of theophylline‐induced cardiac defects with accompanying aortic aneurysm may be related to the development of the conotruncal region of the heart.