The Effect Of Acanthopanax Senticosides B On ATP Sensitive Potassium Channel Of Rabbit Ventricular Myocytes

Objective: We studied the effect of Acanthopanax senticosides B (Sb) on myocardial sarcolemmal ATP sensitive potassium channel(sarcol K_ATP) and mitochondrial ATP sensitive potassium channel (mito K_ATP).Methods: Ventricular myocytes of rabbits were isolated by enzymatic dissociation. Single ventricular myocytes were divided into control group, 10μ mol/L Sb group, 100μmmol/L Sb group. The whole-cell patch clamp technique was used to observe the effect of different concentration of Sb on I_K-ATP and its I—V curve. Single ventricular myocytes were divided into control group, 0.1mmol/L Sb group, 0.5mmol/L Sb group, 1mmol/L Sb group, Glibenclamide group, Glibenclamide + 1mmol/L Sb group. Rhodamine 123 was choosed to stain the mitochondria. Laser scanning confocal microscope (multi-photon) was used to observe the effect of different concentration of Sb on mitochondrial fluorescence intensity for 15 min.Results: The effect of Sb on sarcol K_ATP- I_K-ATP was increased from 2.29± 0.26pA/pF to 6.87±0.38pA/pF, 10.3±0.55pA/pF by 10 μmol/L Sb, 100 μmol/L Sb respectively, and decreased to 3.02±0.23pA/pF, 3.74±0.29pA/pF after application of 3 μmol/L Glibenclimide. Both 10μ mol/L Sb, 100μmol/L Sb made I-V curves ascend. The rise of I—V curve was more obvious in 100μmol/L Sb group. I—V curves of two Sb groups descended after application of Glibenclimide. The effect of Sb on mito K_atp: There was not obvious variation of mitochondrial fluorescence intensity in control group during 15 min observation. Mitochondrial fluorescence intensity increased in 0.1mmol/L Sb group, 0.5mmol/L Sb group and lmmol/L Sb group after treatment. The increments were (10.3±6.78)%, (18.4±.51)% and (24.1 ±7.64)% respectively. The increment of mitochondrial fluorescence intensity was mainly observed in the first five minutes. 3 μmol/L Glibenclamide had no effect on mitochondrial fluorescence intensity and could block the effect of Sb on mitochondrial fluorescence intensity.Conclusion: Sb could open both sarcol Katp and mito Katp- Sb was an effective saponin of Acanthopanax Senticosus Saponins. Opening sarcol Katp and mito Katp was the important mechanism of cardioprotection of Acanthopanecis Senticasi.