Experimental Study on the Protective Effects of Erythropoietin Against Myocardial Infarction in Rats
|School||Tianjin Medical University|
|Keywords||Erythropoietin Myocardial infarction Apoptosis Myocardial fibrosis Administration time|
Background: myocardial infarction (myocardial infarction, MI) is a serious threat to human health diseases. Although interventional treatment for myocardial infarction, the effect is very significant, but still serious complications. Erythropoietin hormone (erythopoietin, EPO) The main role is to promote red blood cell proliferation, maturation, to differentiate into functional cells. Organ protective effect. But also has a protective effect and its mechanism is not clear whether the occurrence of myocardial infarction heart. Objective: To discuss EPO on myocardial infarction cardiac function, and to explore its possible mechanism. Methods: 37 SD rats were randomly divided into four groups, divided into a control group, MI group, MI continuous administration group (EA group) and MI intermittent administration group (EB). Four weeks after the rats in each group following checks: ① ultrasound echocardiography, left ventricular end-diastolic internal diameter (LVEDD), left ventricular systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and fractional shortening (LVFS); (2) hemodynamic monitoring, including peak systolic (LVSP), left ventricular end-diastolic pressure (LVEDP), maximal rate of rise of left ventricular pressure (dP / dt max) and the maximum rate of descent (-dP / dt max); ③ histopathological examination, SH, MI, EA, EB rats hearts were harvested for HE staining and Masson staining. At the same time, respectively, of MI, the transfer of the end of the EA and EB rats line deoxy nucleic acid enzymes dUTP nick end labeling (TUNEL) detection and semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). Each set of data for statistical analysis, defined as P lt; 0.05 difference was statistically significant. The results: 1. Echocardiography, hemodynamic and histopathological examination results to determine the success of this study to establish the model of myocardial infarction in rats. 2 (1) echocardiography Figure MI group were compared with the SH group, EA group, EB group, LVEDD (4.75 ± 0.49mm, 3.91 + 0.42 mm, 4.23 ± 0.42mm. 4.33 ± 0.52mm), LVESD (2.31 ± 0.34 mm, 1.67 ± 0.32 mm, 1.77 ± 0.57mm, 1.96 ± 0.4mm), LVEF (73.83 ± 6.77%, 85.72 ± 5.50%, 81.11 ± 5.92%, 81.08 ± 7.73%), LVFS (50.21 ± 6.98%, 62.26 ± 3.06%, 59.96 ± 9.87%, 60.74 ± 7.81%), differences were statistically significant, the EA group and the EB group found no significant difference; the ② hemodynamics: MI group with SH group, EA group EB group compared LVSP (the 126.96 ± 4.30mmHg, 156.54 ± 4.79 mmHg, 148.34 ± 4.49mmHg 145.81 ± 5.18mmHg), LVEDP (23.09 ± 4.24mmHg 18.30 ± 6.68 mmHg 17.49 ± 7.58mmHg, 16.69 ± 10.26mmHg) , dP / dtmax (2149.49 ± 73.11mmHg / s, 3947.24 ± 92.68 mmHg / s, 3243.77 ± 217.37mmHg / s, 3126.53 ± 77.55mmHg / s), -dP/dtmax (2459.28 ± 1183.73mmHg / s, 3243.77 ± 293.12mmHg / s, 3174.79 ± 233.28mmHg / s, 3196.11 ± 351.93mmHg / s), the differences were statistically significant, EA groups compared with the EB group and found no significant difference. This shows that EPO can improve systolic dysfunction after MI, but no significant difference in improvement of heart function for two different dosing schedules, the normal form of the MI group center muscle cells; (3) Pathological examination visible disappeared, the nucleus contraction was vacuolization the infarcted area surrounding the infiltration of inflammatory cells, increased cardiac myocyte fibrosis; EPO treatment group, EA group EB group, above all improved markedly; ④ TUNEL analysis, MI group apoptotic cells patchy distribution, the EA group and EB groups of apoptotic cells was punctate distribution; quantitative analysis of the MI group and EA group compared to the EB group, the proportion of apoptotic cells, the difference was statistically significant, while the EA group between EB group, the difference was not statistically significant; ⑤ RT-PCR studies MI group of Bax, Caspase-3 mRNA expression increased and was significantly higher than the EA, EB groups (P lt; 0.05), EPO can significantly reduce pro-apoptotic genes Bax, caspase-3 mRNA expression, EA group compared with the EB group, Bax, caspase-3 mRNA expression, no statistically significant differences; of Bcl-2 mRNA expression in the MI group and EA group , EB group compared differences no statistical significance. Conclusion: EPO can improve heart function after myocardial infarction, and play a protective role through the heart of the anti-apoptotic mechanism of myocardial infarction, the molecular biological mechanisms may be associated with decreased pro-apoptotic genes Bax, Caspase-3 mRNA expression Related; differences in the indicators was no statistical difference EPO two different dosing schedules.