INCREASED PRODUCTION OF ENDOTHELIN-1 IN THE HYPERTROPHIED RAT-HEART DUE TO PRESSURE-OVERLOAD

Endothelin-1 (ET-1) has been demonstrated to induce hypertrophy in cul tured cardiac myocytes. We investigated the production of ET-1 in the heart of aorta-banded rats in vivo. Seven days after the banding of th e abdominal aorta, rats developed a significant left ventricular hyper trophy. The tissue content of mature ET-1 and the level of expression of prepro ET-1 mRNA were higher in the left ventricle of aorta-banded rats than in those of sham-operated rats. The expression of prepro ET- 1 mRNA in the right ventricle was not different between the two groups . These findings indicate that the production of ET-1 increased in the hypertrophied left ventricle, thereby suggesting the possible involve ment of endogenous ET-1 in the development of cardiac hypertrophy due to pressure overload.