Changes in calcium handling in atrophic heterotopically isotransplanted rat hearts.

摘要: Atrophy of the rat heart induced by hemodynamic unloading after heterotopic transplantation is associated with impaired relaxation while systolic function remains normal when compared to recipient animal. To identify possible underlying mechanisms for above, we studied some aspects membrane calcium handling using postextrasystolic potentiation contractions in isolated right ventricular papillary muscle and left ventricle Langendorff-perfused heart. We also alterations unloaded those overloaded hypertrophic hearts rats suprarenal aortic constriction. In atrophic degree one extrasystole, considered be proportional trans-sarcolemmal influx Ca2+ during an action potential, was increased 125% hearts. The rate decay which reflects fraction activator recirculating cells via sarcoplasmic reticulum, negatively correlated potentiation, although its mean value not significantly altered. faster sham-operated animals, indicating a decreased Ca2+. data suggest that relative importance fluxes both cardiac atrophy hypertrophy, but their quantitative role control contraction might differ.