Development of the heart in 4-12 mm golden hamster embryo.

ABSTRACT

The developing heart in this study is focused on serial sections of 4-12 mm golden hamster embryos, which were stained with hematoxylin and observed under a light microscope, compared to 10 mm pig embryos. The developing hearts of Golden hamster and pig embryos are very similar. Although the partition of the hamster’s heart is still incomplete, it is clearly divided into four chambers. Two atria are separated by septum primum which grows ventrally but does not reach the endocardial cushion; the foramen primum still remains in the 4 mm stage. This is just a very minor difference compared to that of the 10 mm pig embryo. This foramen is later closed at the older stage. Two ventricles are incompletely separated by the interventricular septum, remaining the interventricular foramen. The ventricle is connected to the bulbus cordis and truncus arteriosus, draining blood to the aortic sac. This study indicates that the developing heart of a golden hamster embryo can be used as a laboratory model instead of that of a pig embryo in order to study the development of a human heart. This will solve the problem of insufficient pig embryos and maintain the efficacy in the study embryology.