Endothelin-1 is produced and secreted by neonatal rat cardiac myocytes in vitro.

Production of endothelin-1 in the cultured neonatal rat cardiac myocytes was investigated. Studies on the cultured cardiac myocytes with reverse transcription-polymerase chain reaction followed by Southern hybridization indicated that mRNA of ET-1(preproET-1 mRNA) was expressed by cardiac myocytes. ET-1 polypeptide was also detected in the cultured cardiac myocytes. Moreover, ET-1 was secreted into the culture medium by them. These results suggest that the cardiac myocytes, which have been regarded as target cells of ET-1, are able to synthesize and secrete ET-1. Furthermore, there may be a possible autocrine mechanism of ET-1 in the myocytes of a heart.