Original Article

Stimulation of Na+-Ca2+ exchange by purified antibody against alpha-2 repeat of Na+-Ca2+ exchanger in rat cardiomyocytes

Qi-long Feng, Dong-mei Wu, Xiang-li Cui, Hua-chen Zhao, Guo-quan Fan, Lu-ying Zhao, Bo-wei Wu


Aim: The aim of the present study was to investigate the effect of the antibody against alpha-2 repeat on Na+-Ca2+ exchanger (NCX) current (INa/Ca). To evaluate the functional specificity of this antibody, its effects on L-type Ca2+ current (ICa,L), voltage-gated Na+ current (INa) and delayed rectifier K+ current (IK) were also observed.
Methods: The whole-cell patch-clamp technique was used in this study.
Results: The antibody against alpha-2 repeat augmented both the outward and inward Na+-Ca2+ exchanger current concentration-dependently, with EC50 values of 27.9 nmol/L and 24.7 nmol/L, respectively. Meanwhile, the antibody could also increase ICa,L in a concentration-dependent manner with the EC50 of 33.6 nmol/L. Effects of the antibody on INa and IK were not observed in the present study.
Conclusion: The present results suggest that antibody against alpha-2 repeat is a stimulating antibody to NCX and could also increase ICa,L in a concentration-dependent manner, but did not have an obvious effect on INa and IK.