Dissociation between factors resulting in hypertrophy and changes in myosin isoenzyme population of the pressure-loaded rat heart

摘要: The interrelationship between cardiac hypertrophy induced by increased pressure load and concomitant changes in the myoeardial myosin isoenzyme population was studied. In order to induce severe on predominantly one ventricle, 6-week-old Wistar rats were fed seeds of plant Crotalaria spectabilis for 4 weeks. ensuing pulmonary hypertension resulted significant only right ventricle (52 %). contrast, affected both ventricles, more so, however, as shown proportion ventricular (VM)-3 given a percentage 3 isoenzymes (right 29.7 ± 4.8 % VM-3 vs. 20.6 5.3 left ventricle; ventricles control 9.3 1.8%). Since thyroid hormones are major determinants since also affects other organs beside lungs, serum thyroxine determined. hormone significantly reduced, not, binding index. results suggest that reduced concentrations circulating contribute shift towards population. normal adult exhibit an loaded it is concluded action hormones, mechanisms responsible expression different isoenzymes, such those arising from altered adrenergic responsiveness transmitter status myocardium.