Atrial-natriuretic-factor mRNA is developmentally regulated in heart ventricles and actively expressed in cultured ventricular cardiac muscle cells of rat and human.

Atrial-natriuretic-factor (ANF) mRNA is actively expressed in ventricular heart myocytes of neonatal rats and fetal and young (2.5-year-old) humans. In rat, ANF mRNA transcription is repressed by the 23rd day of postnatal development, and in human it is no longer detected by the 14th year of development. Its expression is observed in atrial myocytes of both of these species at all ages. ANF mRNA is expressed in primary cultures of ventricular cardiac muscle cells prepared from both neonatal-rat and fetal-human hearts. Surprisingly it is also very actively expressed in cultures of adult rat ventricular cardiac muscle cells. The effect of several hormones on the expression of ANF mRNA in rat and human myocyte cultures was evaluated. These studies demonstrate that ANF mRNA transcription is developmentally regulated in both rat and human heart ventricles and suggest that ventricular cardiac muscle-cell cultures may be useful in studying the regulation of the expression of this gene.