Objective To investigate the protective effect and possible mechanisms of erythropoietin (EPO) on myocardial ischemia-reperfusion injury(MIRI) in rats.Methods Ninety male SD rats were randomly divided into three groups,the sham operation group (n =20),I/RI group (n =20),and EPO treatment combined I/RI group (n =20).The left anterior descending coronary artery was ligated for 30min utes and then loosed for 150min utes to establish the rat model of MIRI.Rats of EPO + I/RI group were injected with EPO(5000u/kg) in abdominal cavity,the others were injected with nomal sodium.The serum MDA content was determined in a method of the thiobarbituric (TBA),the cardiac injury markers(cTn Ⅰ,CK,CK-MB) contents were determined by ELISA.Results The serum MDA and MPO levels of the I/RI group were significantly higher than the sham group,difference was significant(t =10.445,9.848,all P ＜ 0.05) ; Intervention by EPO,the serum MDA and MPO levels of the EPO + I/RI group were significantly lower than the I/RI group,the difference was significant (t =5.087,6.683,all P ＜ 0.05).The serum cTn Ⅰ,CK and CK-MB levels of the I/RI group were significantly higher than the sham group,the difference was significant (t =8.153,5.411,3.729,P ＜ 0.05) ; Intervention by EPO,the serum cTn Ⅰ,CK and CK-MB levels of the EPO+ I/RI group were significantly lower than the I/RI group,the difference was significant(t =4.808,4.089,3.002,all P ＜0.05).Conclusion EPO has protective effect on MIRI,the effect may be through EPO's antioxidant,antiinflammatory and protective effect on myocardial cells in the MIRI rats.

OBJECTIVE:To establish the method for simultaneous determination of berberine hydrochloride and baicalin in Jianpi zhixiening granules. METHODS:HPLC switching walvelength method was adopted. The determination was performed on Hypersil BDS C18 column with mobile phase consisted of methanol-0.45％ phosphoric acid solution-triethylamine(50:49:1,V/V/V) at the flow rate of 1.0 mL/min. The detection wavelength was set at 265 nm(berberine hydrochloride)and 280 nm(baicalin). The column temperature was set at 30 ℃,and sample size was 10 μL. RESULTS:The linear range of berberine hydrochloride and baicalin were 60.3-312.8 ng(r=0.9997)and 81.5-368.9 ng(r=0.9999). The limits of quantitation were 0.6668,0.7740 ng,andthe limits of detection were 0.2226,0.2580 ng,respectively. RSDs of intermediate precision,stability and repeatability tests were all lower than 1.0％. The recoveries were 96.48％-99.30％(RSD=1.06％,n=6) and 95.20％-99.39％(RSD=1.66％,n=6), respectively. RSDs of durability test were all lower than 2.0％. CONCLUSIONS:The method is simple, precise, stable, reproducible,accurate and durable. It can be used for simultaneous determination of berberine hydrochloride and baicalin in Jianpi zhixiening granules.