Abstract
Evaluation of: Giraud GD, Louey S, Jonker S et al. Cortisol stimulates cell cycle activity in the cardiomyocyte of the sheep fetus. Endocrinology 1478(8), 3643-3649 (2006).
The factors that regulate heart growth during late gestation are not clearly understood. However, at birth, the human heart contains the majority of the cardiomyocytes that it will have for life. Cortisol increases during late gestation and is associated with a general slowing of somatic growth, except in the heart. In the study discussed here, a 7-day intracoronary infusion of cortisol increased fetal sheep heart mass but did not increase the size or percentage of binucleated cardiomyocytes, whereas 2-day intravenous infusion of cortisol increased the percentage of proliferating cardiomyocytes. This study provides important data regarding timing during development, duration and dose of exposure to cortisol on cardiomyocyte development during fetal life.