[1 of the molecular factors of development of compensatory myocardial hypertrophy]

Using the method of tryptic digestion, the authors have found that myosin of a hypertrophied myocardium is characterized by a high resistance to proteolysis. At the final stage of compensatory hypertrophy of the myocardium an increased activity of the myofibril catherpsins is discovered. According to the authors, one of the important factors of the compensatory growth of myofibrils consists in the high resistance of the newly synthesized proteins to decay. In characterizing the subunit composition and kinetics of the tryptic decay the possibility of the synthesis of a new population of myosin in the process of compensatory hypertrophy has been postulated. This demonstrates the heterogeneity of the activation of the genetic segments that control the synthesis of protein myofibril subunites with due regard to the regimen ot the myocardium work.