Objective To observe the effects of ranolazine on the action potential and contraction force in guinea pig papillary muscles. To explore the mechanism of ranolazine anti-arrhythmia and myocardial ischaemia.
Methods 18 healthy adult guinea-pigs were randomly divided into H2O2 (200 mmol/l) groups, ranolazine (10 mmol/l) +H2O2 groups and TTX (2 mmol/l) +H2O2 groups, with six guinea pigs in each group compared before and after administration to observe the effects of ranolazine on the papillary muscles.
Results H2O2 could increase action potential durations measured at 50% repolar… moreization levels and 90% repolarisation levels were prolonged (p<0.001). There was reduced myocardial contractility (p<0.05)in contraction force in the guinea pigs compared to before administration. Ranolazine can inhibit action potential durations measured at the 50% repolar… moreization levels and the 90% repolarisation levels were prolonged by H2O2, but the effect was weaker compared to that of TTX. Ranolazine and TTX could improve myocardial contractile force by reducing the H2O2-induced.
Conclusion ranolazine could reduce action potential duration the H2O2-induced and increase contraction force. TTX performs a similar role.
- the action potential
- contraction force