Erythrocyte (Ca2+ + Mg2+)-ATPase activity and calcium homeostasis in Duchenne muscular dystrophy

The study on intramyocardial calcium overload and apoptosis induced by coxsackievirus B3

The isolated cardiac myocytes of rats were immediately infected by cosackievirus B3 (CVB3) to investigate the effects of such procedure on the cell cycle, apoptosis and intracellular ionized calcium (Ca2+ i) of cardiac myocytes. Newborn Balb/c murine cardiac myocytes were cultivated, then infected by CVB3. Intracellular Ca2+ i was measured by flow cytometer. The calcium in the medium for culturing cardiac myocytes was detected by using atom absorb spectrum test. It was found that CVB3 could markedly inhibit the differentiation and proliferation of the infected cardiac myocytes and induce the apoptosis. The intracellular Ca2+ i level in the infected group was significantly higher than in the control group (P < 0.01). The calcium concentration in the medium for culturing cardiac myocytes in the infected group was significantly lower than in the control group (P < 0.05). It was suggested that the apoptosis and intracellular calcium overload of the CVB3-affected cardiac myocytes are likely to play an important role in the pathogenesis of viral myocarditis.

Ca content of human erythrocytes. What is the true value?

It has been generally accepted that the Ca content of washed erythrocytes is in the range of 1 - 3 X 10(-5) mole/l cells (1-10). These values were obtained after samples were treated in various way for Ca measurement. However, by using a simplified careful preparation technique to avoid Ca contamination together with inductively coupled argon plasma emission spectroscopy, we have found that the Ca content of erythrocytes washed with nominally Ca2+-free solution, is one order of magnitude lower than the reported values, in the range of 1 X 10(-6) moles/l cells.