The Effects Of Extract Of Maize Plumule On Myocardial Ischemia

To observe the protective effects of Extract of Maize Plumule (EMP) on myocardial ischemia, in this paper, the effects of EMP on three myocardial ischemia models were studied. Results are showed as followed:1 On the myocardial ischemia model induced by isoprenaline(Iso)in rabbits, rabbits were supplied with different dosage of EMP(20mg?kg-1,40mg?kg-1,80mg?kg-1,ig)previously. Two weeks later, rabbit myocardial ischemia was induced by over-dosed Iso (10mg?kg-1, twice in a day) injected intraperitoneally. The results showed that compared with the model control group, EMP (40mg?kg-1,80mg?kg-1) reduced the heart rate and height of J point; ameliorated the degree of myocardial ischemic injury; significantly or obviously reduced the activities of AST, LDH, CK in the serum of rabbits(P<0.01 or P<0.05), increased the NO content in the serum(P<0.01 or P<0.05), increased activities of GSH- pX and SOD(P<0.01 or P<0.05)and decreased MDA contents in the myocardium and serum(P<0.01 or P<0.05).2 On the myocardial ischemia model induced by pituitrin(Pit)in rabbits, rabbits were supplied with different dosage of EMP(20mg?kg-1,40mg?kg-1,80mg?kg-1,ig)previously. Two weeks later, rabbit myocardial ischemia was induced by Pit (2.0U?kg-1.Soluted in 3ml normal saline and injected in 20 seconds) injected intravenously. The results showed that compared with the model control group, EMP (40mg?kg-1,80mg?kg-1) alleviated the changes of heart rates, S-T section and T wave; significantly or obviously reduced the activities of AST, LDH, CK in the serum(P<0.01 or P<0.05), increased activities of GSH-pX and SOD(P<0.01 or P<0.05)and decreased MDA contents in the myocardium(P<0.01 or P<0.05).3 On the myocardial ischemia injured model of cultured rat cardiomyocyte,30 minutes after Iso adding, cardiomyocytes were supplied with different dosage of EMP ( 10 mg?L-1,20mg?L-1,40mg?L-1). The results showed that compared with the model control group, EMP (40mg?L-1) improved cell morphology under ischemia, increased the density and survival rate of cardiomyocytes; significantly or obviously reduced the activities of AST, LDH, CK(P<0.01 or P<0.05),increased activities of GSH-pX and SOD (P<0.01)and decreased MDA contents in the cell culture medium(P<0.05); promoted the expression of BCl-2 and inhibited the expression of NF-κB.Conclusion: EMP possessed the protective effects on myocardial ischemia. The possible mechanism related with: the free radical scavenging effect, inhibition of lipid peroxidation and maintenance of the integrality of cell membrane; alleviation of vascular endothelial cells injury; inhibition of myocardial apoptosis.