Prodynorphin mRNA expression in adult cultured rat ventricular cardiac myocytes.

Prodynorphin mRNA was synthesized both in rat atrial and ventricular tissue, as well as in adult cultured rat ventricular cardiac myocytes. In the cultured cells, the content of prodynorphin mRNA did not differ from that detected in the original ventricle, indicating that the myocardial cell is an important source for prodynorphin mRNA in the rat ventricular tissue. This study demonstrated the presence of immunoreactive dynorphin B-like material in the cultured cardiomyocytes. Gel permeation chromatography analysis of this material revealed the presence of forms with an apparently higher molecular weight than authentic dynorphin B.