Cardiac myocytes differ in mRNA composition for sarcoplasmic reticulum Ca2+ channels and Ca2+ pumps.

none7Abstract non disponibilenoneL. GORZA; S. VETTORE; P. VOLPE; V.SORRENTINO; J.L. SAMUEL; M. ANGER; A.M. LOMPRE'Gorza, Luisa; Vettore, Silvia; Volpe, Pompeo; V., Sorrentino; J. L., Samuel; M., Anger; A. M., Lompre

Altered sarcoplasmic reticulum Ca2+-ATPase gene expression in the human ventricle during end-stage heart failure

A decrease in the myocardial level of the mRNA encoding the Ca2+-ATPase of the sarcoplasmic reticulum (SR) has been recently reported during experimental cardiac hypertrophy and failure. To determine if such a deficit occurs in human end-stage heart failure, we compared the SR Ca2+-ATPase mRNA levels in left (LV) and right ventricular (RV) specimens from 13 patients undergoing cardiac transplantation (6 idiopathic dilated cardiomyopathies; 4 coronary artery diseases with myocardial infarctions; 3 diverse etiologies) with control heart samples using a rat cardiac SR Ca2+-ATPase cDNA probe. We observed a marked decrease in the mRNA for the Ca2+-ATP-ase relative to both the 18S ribosomal RNA and the myosin heavy chain mRNA in LV specimens of patients with heart failure compared to controls (-48%, P < 0.01 and -47%, P < 0.05, respectively). The LV ratio of Ca2+-ATPase mRNA to 18S RNA positively correlated with cardiac index (P < 0.02). The RV ratio correlated negatively with systolic, diastolic and mean pulmonary arterial pressures (P < 0.02, P < 0.02, and P < 0.01, respectively). We suggest that a decrease of the SR Ca2+-ATPase mRNA in the myocardium plays an important role in alterations of Ca2+ movements and myocardial relaxation reported during human end-stage heart failure.link_to_subscribed_fulltex