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Aortic aneurysm associated with cardiac defects in theophyline stimulated chick embryos
Insights
Theophylline exposure in embryonic chicks caused aortic aneurysms in 63% of cases. Many also developed ventricular septal defects, suggesting a link to conotruncal heart development.
Area of Science:
- Developmental biology
- Cardiovascular research
- Teratology
Background:
- Theophylline is a methylxanthine drug with known effects on cellular processes.
- Congenital heart defects represent a significant global health burden.
- Understanding the teratogenic potential of common substances is crucial for prenatal health.
Purpose of the Study:
- To investigate the effects of theophylline on embryonic cardiac development.
- To determine the incidence of specific cardiac malformations following theophylline exposure.
- To explore the potential mechanisms underlying theophylline-induced cardiovascular defects.
Main Methods:
- Administration of theophylline (0.02 M in 0.15 M saline) to embryonic chick embryos (Hamburger-Hamilton stages 24-27).
- Topical application of the drug to the chorioallantoic membrane near the embryonic heart.
- Necropsy and examination of cardiac structures for malformations.
Main Results:
- A significant incidence of ascending aortic aneurysms (63%) was observed in theophylline-exposed embryos.
- Among embryos with aortic aneurysms, 48% also exhibited ventricular septal defects.
- Rare cases of truncus arteriosus were noted, indicating broader conotruncal abnormalities.
Conclusions:
- Theophylline exposure during critical developmental windows can induce significant cardiovascular malformations in avian embryos.
- Aortic aneurysms and septal defects appear to be common outcomes, potentially linked to disruptions in conotruncal region development.
- This model provides insights into the teratogenesis of theophylline and its impact on heart morphogenesis.
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.