MMP-9在慢性缺氧大鼠血浆中表达及唐古特青兰的保护作用

The expression of matrix metalloproteinase 9 in plasma of chronic hypoxia rats and the protective effect of Tanggu Qinglan on myocardial injury in rats

目的:探讨基质金属蛋白酶9(MMP-9)与脑钠肽(BNP)在慢性缺氧所致心肌损伤的SD大鼠血浆中表达情况及其相关性,以及唐古特青兰对慢性缺氧所致SD大鼠心肌损伤的保护作用。方法:将60只成年健康雄性SD大鼠随机分为3组,每组20只,分别标记为对照组(A组)、慢性缺氧损伤+唐古特青兰干预组(B组)、慢性缺氧损伤组(C组),B组大鼠经腹腔注射2g/kg的唐古特青兰,A组和C组则注射等量的生理盐水注射液。给药24h后,将B组和C组大鼠放入乏氧动物饲养箱内饲养,通入氮氧混合气体(N2∶O2=90∶10),测氧仪监测乏氧箱内氧浓度,乏氧箱内放置氯化钙和钠石灰吸收箱内CO2和H2O,8h后将大鼠取出,置于常氧动物饲养箱内继续饲养,第2天重复以上过程,共持续2W。ELISA法检测血浆BNP与MMP-9表达情况及其相关性。结果:B组大鼠血浆中BNP及MMP-9表达均明显低于C组(P<0.05),而明显高于A组(P<0.05),MMP-9与BNP呈正相关(rA=0.823,rB=0.805,rC=0.727)。结论:慢性缺氧可以诱导大鼠血浆中MMP-9、BNP表达增加,而唐古特青兰能够改善这种慢性缺氧所致心肌损伤,慢性缺氧后BNP的迅速分泌可能是促进MMP-9表达的原因之一,慢性缺氧时测定血浆BNP与MMP-9浓度对于判断心功能及心室结构重塑从而间接判断预后有重要意义。

Objective:To investigate the expression of matrix metalloproteinase 9(MMP-9)and brain natriuretic peptide(BNP)in the plasma of SD rats with myocardial injury caused by chronic hypoxia and its correlation.To investigate the protective effect of Tanggu cyan on myocardial injury induced by chronic hypoxia in SD rats.Methods:Sixty adult healthy male SD rats were randomly divided into three groups with 20 rats in each group.The rats in group B were intraperitoneally injected with 2 g/kg of Tanggu qinglan,while the rats in group A and Group C were injected with the same amount of normal saline.After 24 h of administration,the rats of group B and Group C were put into the hypoxic animal feeding chamber and fed with a mixture of nitrogen and oxygen(N 2∶O 2=90∶10).The oxygen concentration in the hypoxic chamber was monitored by an oxygen meter.Calcium chloride and sodium lime were placed in the hypoxic chamber to absorb CO 2 and H 2O.After 8 h,the rats were taken out and kept in a conventional oxygen tank.Repeat the process the next day for 2 weeks.ELISA was used to detect the expression of BNP and MMP-9.Results:BNP and MMP-9 expression in the plasma of rats in group B were significantly lower than that in group C and higher than that in group A,and the difference was statistically significant(P<0.05).Mmp-9 was positively correlated with BNP(rA=0.823,rB=0.805,rC=0.727).Conclusion:Chronic hypoxia can induce the expression of MMP-9 and BNP in the plasma of rats.The rapid secretion of BNP after chronic hypoxia may be one of the reasons to promote the expression of MMP-9.The determination of plasma BNP and MMP-9 concentration during chronic hypoxia is of great significance for the determination of cardiac function and ventricular structure remodeling,thus indirectly determining the prognosis.