Abnormal Organogenesis in the Cardiovascular System

Rotation of the junction of the outflow tract and great arteries in the embryonic human heart

“…What accounts for the rapid growth of the great arteries in the embryo? It has been suggested that vessel size is a direct function of flow volume (Rodbard, 1975;Jaffee, 1977). This concept is consistent with observed changes in coronary artery sizes as a function of tissue mass perfused (Hutchins et al, 1977).…”

“…There are numerous descriptions of cardiogenesis in the human embryo (Davis, 1927;DeVries and Saunders, 1962;Meredith et al, 1979;McBride et al, 1981), but mechanisms used to explain the development of the heart have been varied and largely unconfirmed. Recent theories have suggested that combinations of hemodynamic forces induced by blood flow from the ventricles (DeVries and Saunders, 1962;Winn and Hutchins, 1973;Koolman, 1976;Jaffee, 1977;Conte and Grieco, 1980;McBride et al, 1981), physical restraining forces from surrounding organs (Davis, 1927;Meredith et al, 1979;Hutchins et al, 1979), mesenchymal and extracardiac cytodifferentiation (Manasek, 1981), major axes of tension (Thompson and Fitzharris, 1979), hydration of cardiac jelly (Manasek, 1981), and differential growth (Davis, 1927;DeVries and Saunders, 1962;de la Cruz and Sanchez, 1977;Manasek, 1981) may be responsible for the formation of the outflow tract and the great arteries. In the present study, data collected from morphometric studies of embryos suggest the hypothesis that a differential rate of growth of the great arteries with respect to the rest of the heart, and the limiting confines in which the heart is developing, could be major factors producing the definitive normal relationship between the heart and great arteries.…”

Morphogenesis of Aortic Arch Malformations in Rat Embryos after Maternal Treatment with Glycerol Formal during Pregnancy

“…This pattern was observed also by Grabowski [1964Grabowski [ , 1966 and Grabowski and Chernoff[ 1970] in chick and rat embryos treated with different teratogenic agents; it could be related to an increase in extracellular and circulating fluids (edema and hypervolemia) that could result in alterations of blood pressure and flow patterns. It is well known that these hemodynamic factors are very important in molding the embryonic cardiovascular sys tem [Jaffee, 1965[Jaffee, , 1977. All malformations we have observed may be related to an anomalous regression or persistence of embryonic vessels.…”

The role of embryology in teratological research, with particular reference to the development of the neural tube and heart

“…The cellular interactions which are thought to be involved during these stages of cardiac morphogenesis have been reviewed by Manasek (1976). It has also been proposed, on the strength of experimental findings, that some, possibly even a considerable proportion, of the changes involved in cardiac morphogenesis are brought about in response to alterations in cardiovascular haemodynamics (see recent review by Jaffee, 1977). Examples of morphological changes which are almost certainly brought about in this way are the development of the spiral septum in the arterial outflow region of embryonic heart, and, much later, the considerable circulatory changes which take place within the heart and in the circulation at birth.…”