Objective: To study the positive inotropic effect of higenamineand 6-gingerol and their compatibility on normal cardiac myocytes. Method: The left ventricular cardiac myocytes were isolated from normal rat by traditional Langendroff method. The cardiac myocytes contraction were detected by using different monomers and their compatibility (Ion Optix cell dimensioning systems). The detections included the maximum velocity of systolic and diastolic (±dp/dt)

contraction amplitude (ph/bl) and the time course constant of 50% systolic and diastolic (T50S

T50D). Result: 0.03-1 μmol·L-1 higenamine enhances±dp/dt

ph/bl with a dose- dependent manner

but not influenced the T50S and T50D. The minimum effective concentration was 0.1 μmol·L-1

EC50 was approximately 0.205 μmol·L-1

and 1 μmol·L-1 could get the maximum efficacy. The maximum efficacy of ph/bl

+dp/dt

-dp/dt was up to 234%

219% and 272%. It's could induce the arrhythmia contraction when the dose was higher than 1 μmol·L-1. 3-30 μmol·L-1 6-gingerol had not any effects of contractility on cardiac myocytes. However

the higher concentrations than 30 μmol·L-1 also induced the arrhythmia contraction. This research also investigated the 3

10 μmol·L-1 6-gingerol compatibility with 0.1 μmol·L-1 and 0.3 μmol·L-1 higenamine. Mutual compatibility could not enhance the positive inotropic effect of higenamine. Conclusion: Higenamine plays the positive inotropic effect

and 6-gingerol has nether any effects on monomer

nor compatibility with higenamine.