Effects of taurine-magnesium coordination compound on abnormal calcium current induced by hypoxia-reoxygenation in rat ventricular cardiomyocytes / 中国药理学通报

ABSTRACT

Aim To investigate the effects of TMCC on abnormal L-type calcium current (ICa,L) in rat ventric-ular cardiomyocytes during hypoxia-reoxygenation to find out the mechanism of antiarrhythmic effect. Methods Whole-cell patch clamp was used to record ICa,L in the ventricular cardiomyocytes during hypoxia-reoxygenation in rat under amiodarone and different concentrations of TMCC. Results In hypoxia-reoxy-genation model, peak ICa,L increased from ( 3. 35 ± 0. 50 ) pA/pF to ( 5. 69 ± 0. 25 ) pA/pF ( n =6 , P 0. 05),(4. 41 ± 0. 22) pA/pF, (3. 82 ± 0. 21)pA/pF(n=6, P<0. 01) by TMCC(100, 200, 400 μmol·L-1 ) and amidodarone 24. 24 μmol·L-1 restored peak ICa,L to(3. 66 ± 0. 27)pA/pF (n=6,P<0. 01 ) . Compared to control group, hypoxia-reoxy-genation turned ICa,L steady-state activation curves to left and inactivation curves to right, which quickened activation and slowed inactivation, TMCC ( 200, 400μmol · L-1 ) and amiodarone could restore the left shift activation curves and right shift inactivation curves. Conclusion TMCC can concentration-de-pendently restore the increase of calcium current due to hypoxia-reoxygenation by promoting inactivation process and inhibiting activation process, and the effect is equal to that of amiodarone. TMCC blocks ICa,L of the ventricular cardiomyocytes, which may be one of its antiarrhythmic mechanisms.