Effects And Mechanisms Of Active Fraction Of Potentilla Anserine L. On Acute Myocardial Ischemia Injury In Mice

Objective: To study the effect of ND (active fraction of Potentilla anserine L. ) on pituitrin-induced acute myocardial ischemia injury in mice, and approach the possible mechanisms.Methods: The mice were injected pituitrin (20U/kg, 30min) intraperitoneally to set up acute myocardial ischemic model, and electrocardiograms were monitoringed. Then, the effect of different dose ND on acute myocardial ischemia injury in mice were studied by HE staining, Nagar Olsen specific staining, transmission electron microscope and biochemical indicators (LDH,CK). The possible mechanisms on acute myocardial ischemia injury in mice were approached by biochemical indicators(SOD,MDA,NO,NOS), immuno- histochemistry stain (iNOS,p38,p-p38,cyt-c,caspase3-p20) and RT-PCR(caspase9,caspase3).Results: 1 The effect of ND on acute myocardial ischemia injury in mice: (1) Electrocardiogram: all the three doses of ND could significantly diminish J spot change (P<0.01), but there were no dose dependent.And ND had no effect on the decreased heart rate induced by ischemic.(2) Nagar-Olsen stain: after the treatment of ND,the red dye regions of muscular tissues significantly diminished.(3) Transmission Electron Microscope: after the treatment of ND, ultramicrostructure changes, such as the myofibrils arranged disorderly, the membrane and cristae of mitochondria dissolved, and the interstitial substance edemae were obviously lessened.(4) Serum Biochemical Indicators: the high and middile dose ND could decreased the activities of LDH(P<0.01), CK(P<0.01) , no significant difference was observed between low dose ND group and model group.2 The possible mechanisms of ND on acute myocardial ischemia injury in mice: (1) Serum Biochemical Indicators: the high and middile dose ND could raise the activities of SOD (P<0.01), decrease the production of MDA (P<0.01), depress the content of NO (P<0.01), heighten the level of NOS(P<0.01)compared with model group , no significant difference was observed between low dose ND group and model group. (2) Immuno-histochemistry Stain :the high and middile dose ND could depress the express levels of iNOS(P<0.01), p-p38 (P<0.01)and caspase3-p20(P<0.01) on acute myocardial ischemia injury muscular tissues compared with model group, no significant difference was observed between low dose ND group and model group. Only the high dose ND could depress the express level of cyt-c(P<0.01). (3)RT-PCR: the high, middile and low doses ND could depress the express level of caspase9 mRAN on acute myocardial ischemia injury muscular tissues compared with model group (P<0.01).Conclusions: ND (active fraction of Potentilla anserine L.) could diminish J spot change of electrocardiogram, relieve the area of cardiac musclar injuries on Nagar-Olsen stain, lessen the degree of ultramicrostructure changes, and reduce the release of cardiac muscular enzymes, release the extent of cardiac muscular injuries, indicating its protection on pituitrin-induced acute myocardial ischemia injury in mice. The possible mechanisms of this protection were: to decrease the production of oxygen free radical, elevate the cleaning ability to oxygen free radical, increase the synthesis of NO and inhibit its excess production, reduce the transmembrane deliver of injury signal by p-38MAPK route, depress cyt-c level, weaken caspase cascade reaction and intercept the happeness of apoptosis.