[Autoradiographic study of protein synthesis in the muscle and interstitial elements of the myocardium during development of compensatory heart hyperfunction].

In the emergency stage of heart compensatory hypertrophy induced by constriction of the abdominal aorta, quantitative autoradiographic localization of newly synthesized proteins and RNA was studied in the left ventricular myocardium of adult rats 1 and 3 hours after the injection of 3H-leucine and 3H-uridine, respectively. The animals were sacrificed 1, 5 and 10 days after the operation. The amount of the autoradiographic grains was measured separately for muscle and interstitial components of the myocardium. A substantial increase in protein synthesis as regards muscle and non-muscle components was recorded only on day 10 of the experiment. At the same time incorporation of amino acids into protein of muscle and interstitial components was found to be higher by 42 and 60%, respectively. The labeling of RNA in muscle cells was similar to that of protein. In interstitial cells, the content of labeled RNA consistently rose throughout the whole experiment.