Transposition of the great vessels and other cardiovascular abnormalities in rat fetuses induced by trypan blue

Abstract

Abstract Complete and partial transposition of the great vessels, dextrocardia, and absence or stenosis of the tricuspid or mitral valves were encountered singly or in combination in rat fetuses from mothers injected with trypan blue solution subcutaneously on the 8th or 9th day of gestation. Hearts with transposition of the great vessels were usually characterized by shortness of the aorta and pulmonary trunk, cranial location of the aortic valve, displacement of the coronary arteries, and a channel or “track” extending from the cranial portion (infundibulum) of the right ventricle to the commencement of the transposed pulmonary trunk. Inadequate expansion of the atrioventricular ring about the 12th or 13th day of gestation possibly leads to deformity of the atrioventricular cushions and to absence or stenosis of the tricuspid or mitral valves. Sinuosity of the truncus arteriosus seen in many 13th day and older embryos of the trypan blue series is considered a significant factor in the development of transposition of the great vessels.