Rat Heart in the Prenatal and Postnatal Period of Ontogenesis
Rats are the most common laboratory animals used in experiments to evaluate the cardiotoxic, including teratogenic, effects of therapeutic agents. It is necessary to have a detailed understanding of the developmental and structural features of the heart of model animals for a correct interpretation of experimental studies results. Cardiomorphogenesis in rats, in comparison with that in humans, has the following features: (1) the peak of the proliferative activity of cardiomyocytes decreases on the late stages of the prenatal period of ontogenesis; (2) the transition of the myocardium from the hyperplastic to the hypertrophic growth type occurs in the early postnatal period of ontogenesis; (3) hypertrophic type of myocardial growth consists in the formation of cardiomyocytes with several diploid nuclei – multinucleated cardiomyocytes.