[Preliminary study on mechanism of electroacupuncture with the involvement of SERCA2a/PLB on the synergistic and attenuated effect of aconitine in treatment of heart failure]

Objective: To investigate the mechanism of electroacupuncture (EA) with the involvement of sarcoplasmic reticulum Ca²⁺-ATPase2a (SERCA2a)/phospholamban (PLB) on the synergistic and attenuated effect of aconitine for heart failure.

Methods: Thirty SPF-ranked SD rats were randomly divided into a control group, a model group, an EA group, an aconitine group and an EA plus aconitine group, with 6 rats in each group. The rat model of acute heart failure was established by infusion of high-dose propranolol hydrochloride solution into the right femoral vein. After stabilized for 10 min in the modeled rats, EA was exerted at "Neiguan" (PC 6), with disperse-dense wave, 2 Hz/15 Hz in frequency, 3 mA in intensity, for 30 min in the EA group and the EA plus aconitine group; aconitine solution (10 μg/kg) was injected from the left femoral veins in the rats in the aconitine group and the EA plus aconitine group. Hemodynamic indexes such as the left ventricular systolic pressure (LVSP) and the maximum rate of increase/decrease of left ventricular pressure (±dp/dt_max) were detected and arrhythmia types were observed and scored. SERCA2a protein and PLB protein expressions in left ventricular myocardial tissue of rats were detected by multiplex fluorescence Western blot.

Results: Compared with the control group, LVSP and ±dp/dt_max all were decreased after modeling and at each time point after intervention in the model group (P<0.01). Compared with the model group, ±dp/dt_max was increased in the aconitine group and the EA group at 1 min after intervention (P<0.01, P<0.05), +dp/dt_max was increased at 10 to 60 min after intervention in the aconitine group and at 20 to 60 min after intervention in the EA group (P<0.01, P<0.05), LVSP was increased at 1 min after intervention in the EA group (P<0.01), while LVSP and ±dp/dt_max were all increased at 1 to 60 min after intervention in the EA plus aconitine group (P<0.01, P<0.05). Compared with the aconitine group, LVSP and +dp/dt_max were increased at 1 min after intervention in the EA group (P<0.01, P<0.05), LVSP and ±dp/dt_max at 1 min after intervention while +dp/dt_max at 20 to 60 min after intervention were all increased in the EA plus aconitine group (P<0.01, P<0.05). Compared with the EA group, +dp/dt_max was higher at 10 to 60 min after intervention in the EA plus aconitine group (P<0.01). Compared with the model group, arrhythmia score was higher in the aconitine group (P<0.01). Compared with the aconitine group, arrhythmia score was lower in the EA group and the EA plus aconitine group (P<0.01). As compared with the control group, the expression of SERCA2a protein in the left ventricular cardiomyocytes was decreased (P<0.01), while the expression of PLB protein was increased in the model group (P<0.01). Compared with the model group, the expression of SERCA2a protein was increased in both the EA group and the EA plus aconitine group (P<0.05, P<0.01), and PLB protein expression was decreased in each intervention group respectively (P<0.01, P<0.05). As compared with the EA group and the aconitine group, the expression of SERCA2a protein was increased and the expression of PLB protein was decreased in the EA plus aconitine group separately (P<0.05, P<0.01).

Conclusion: The intervention with electroacupuncture achieves the synergism/ attenuation effect of aconitine for the improvements in heart failure probably by up-regulating the expression of SERCA2a and down-regulating the expression of PLB in myocardial tissue.