倒卵叶五加总皂甙对大鼠心肌缺血/再灌注损伤后细胞凋亡的作用及机制

目的　探讨倒卵叶五加总皂甙 (SAOH)对大鼠缺血心肌再灌注后细胞凋亡的作用。方法　采用结扎左冠状动脉前降支再灌注复制大鼠心肌缺血再灌注损伤 (IRI)的模型 ,结扎前 10 min舌下静脉注射 SAOH,测定心肌缺血3 0 min后再灌注 6h心肌组织丙二醛 (MDA)和血浆超氧化歧化酶 (SOD)的含量 ,并用末端脱氧核苷酸转移酶介导的带生物素的 d UTP缺口末端标记 (TUNEL)的方法及免疫组化观察左心室心肌细胞凋亡及凋亡相关基因 Bcl- 2和 Bax的蛋白表达。结果　再灌注 6h后 ,SAOH1 组 (5 0 mg/ kg)及 SAOH2 组 (10 0 mg/ kg)较 IRI组 ,心肌组织 MDA含量明显减少 [(4.89± 0 .2 6)、(3 .5 7± 0 .2 1) nm ol/ mg· pro vs(6.97± 0 .3 4) nmol/ mg· pro,P值均 <0 .0 1];血浆 SOD活性明显提高 [(9.88± 0 .18)、(11.40± 0 .3 7)μIU / L vs (3 .3 9± 0 .2 4)μIU / L ,P值均 <0 .0 1];心肌细胞凋亡指数 (AI)显著减少 [(14.67± 3 .0 5 ) %、(7.49± 2 .62 ) % vs(2 1.96± 7.68) % ,P值均 <0 .0 1];Bax蛋白表达明显减少 [(7.73± 1.84) %、(5 .0 2± 1.0 1) % vs (18.5 9± 5 .68) % ,P值均 <0 .0 1];而心肌 Bcl- 2蛋白的表达显著增加 [(12 .5 1± 3 .42 ) %、(17.48± 4.72 ) % vs(7.3 2± 2 .0 5 ) % ,P值 <0 .0 5 ,<0

Effects of Saponin of Acanthopanax Obovatus Hoo on myocardial apoptosis induced by ischemia- reperfusion in jury in rats and its mechanisms

Objective To study the effects of Saponin of Acanthopanax Obovatus Hoo (SAOH) on apoptosis of myocardium induced by ischemia reperfusion injury (IRI) in rats. Methods Ischemia reperfusion model was induced by left descending anterior coronary artery (LAD) ligation for 30 min, followed by 6 h of reperfusion. 10 min befor LAD ligation, SAOH was administered by the route of sublingual vein injection. At the end of reperfusion, to measure the level of malondialdehyde (MDA) in myocardium, and superoxide dimutase (SOD) in plasma by colorimetry, to investigate myocardium apoptosis by terminal deoxynuleotide transferase mediated digoxin dUTP nick end labeling (TUNEL) method, and to observe the proteins expression of Bcl 2 and Bax gene in left ventricular myocardium after reperfusion by immunohistochemical method. Results Compared with IRI group, SAOH 1 (50mg/kg) group and SAOH 2 (100mg/kg) group markedly increased the activity of SOD in plasma[(9.88±0.18),(11.40±0.37)μ IU/L in SAOH 1 and SAOH 2 group, respectively vs (3.39±0.24)μ IU/L in IRI group, all P <0.01],decreased the content of MDA in myocardium [(4.89±0.26),(3.57±0.21) nmol/mg pro vs (6.97±0.34) nmol/mg pro, all P <0.01], obviously decreased apoptosis index (AI)[(14.67±3.05)%,(7.49±2.62)% vs (21.96±7.68)%,all P <0.01],and obviously decreased the protein expression of Bax gene[ (7.73±1.84)%,(5.02±1.01)% vs (18.59±5.68)%,all P <0.01], but increased the protein expression of Bcl 2 gene [(12.51±3.42)%,(17.48±4.72)% vs (7.32±2.05)%, P <0.05, P <0.01], the ratio of Bax to Bcl 2 was descent incidentally[(0.63±0.25), (0.29±0.57) vs (3.32±0.10), all P <0.01].Conclusions SAOH could obviously decreases myocardial apoptosis induced by IRI. The mechanisms may be associated with enchancing the ability of SOD in plasma, decreasing the level of MDA in myocardium, downregulating the protein expression of Bax gene, and upregulating the protein expression of Bcl 2 gene.