Regression of cardiac hypertrophies of various origin

Abstract

Enlargement of the heart was produced in rats by four methods: (a) unilateral nephrectomy with DOC pellet implantation and salt loading, (b) experimental hyperthyroidism, (c) experimental aortic coarctation, and (d) nutritional anemia. All enlargements proved to be reversible if the provoking stimulus was removed. In hearts enlarged by anemia up to 80–100%, the extra protein and RNA synthesized during the process of accelerated growth of the heart disappeared as the size of the heart reverted to normal. In this way, the concentration of these two macromolecules remained the same, in spite of the changes in the size of the heart. On the other hand, a large part of the new DNA was not removed during regression.