CHANGES IN INTRACELLULAR AND EXTRACELLULAR CALCIUM-CONCENTRATION OF THE MYOCARDIAL-CELLS DURING HEART-FAILURE IN CHILDREN

Objective To explore the relationship between heart failure and change s in intracellular calcium concentration of the myocardium. Methods Th e intra-and extracellular concentration of ionized calcium and total c alcium of myocardium in 11 cases of heart failure was measured using c alcium fluorescence indicator Fura-2 and atom absorption spectrophotom etry. The activity of the erythrocyte membrane pump was determined wit h hemolysate chemical method. Results The concentration of ionized cal cium in myocardial cells and the erythrocyte was significantly higher in the patients with heart failure (280. 85 +/- 47. 48 nmol/L, 1. 76 /- 0. 04 F-335/F-385) than in those without heart failure (121. 88 +/- 13. 15 nmol/L, 1. 47 +/- 0. 08 F-335/F-385). Total calcium in the ery throcyte was also increased markedly in the patients with heart failur e, but the activity of the erythrocyte membrane pump was lower than in those without heart failure. The intracellular calcium of the periphe ral erythrocyte and the activity of membrane pump returned to normal a fter the heart failure was cured. Conclusion There is excessive calciu m accumulation in the myocardium and erythrocyte and the latter may be a cause of the disturbance of myocardial diastolic function during he art failure.