血管再生在小鼠脓毒症心肌损伤中的作用

目的 对脓毒症小鼠发生心肌损伤时心肌血管再生和细胞凋亡情况及相关机制的研究.方法 将40只8周左右的雄性C57BL/6小鼠随机(随机数字法)分为两组,实验组(n=20)和对照组(n=20),实验组用脂多糖(LPS)腹腔注射(10 mg/kg),对照组给以生理盐水(10mg/kg),6h后超声观察两组小鼠心功能(n=40),后取两组小鼠心脏、肺脏、肾脏组织石蜡包埋切片做HE染色(n=6)观察病理学变化鉴定模型,免疫组化(n=3)PECAM -1、α-SAM染色观察心肌血管再生,心肌细胞凋亡染色(TUNLE) (n=3)观察细胞凋亡情况,提取心脏组织RNA(n=6)通过RT-PCR技术对HIF-1α等血管再生因子进行检测,所得数据处理均采用独立样本t检验.结果 实验组与对照组相比小鼠心脏左室舒张期前壁厚度(t=-4.60,P＜0.05)、左室收缩期前壁厚度增厚(t=-3.24,P＜0.05),左心室舒张期内径减小(t=3.57,P＜0.01),每搏输出量下降(t=5.51,P＜0.01),免疫组化染α-SAM抗体显示实验组心脏新生血管数增加(t=-11.00,P＜0.01),凋亡染色(TUNEL)存在心肌细胞凋亡[实验组比对照组:(191.31±5.41) vs.(52.24±4.32)],RT-PCR显示HIF-1α表达显著增高(t=-8.12,P＜0.05).结论 脓毒症小鼠存在明显心肌血管再生、细胞凋亡及心功能障碍,导致血管再生的通路有低氧诱导因子( HIF -1α)的参与.

The role of angiogenesis in myocardial injury in septic mice

Objective To investigate the angiogenesis,apoptosis and their mechanisms in septic mice with myocardial injury.Methods Forty male C57BL/6 mice aged 8 weeks were randomly ( random number) divided into two groups:the sepsis group and the control group.The mice of sepsis group were treated with lipopolysaccharide (LPS) ( 10 mg/kg Intraperitoneal injection) while the mice of control group were treated with saline solution instead (10 mg/kg Intraperitoneal injection).Cardiac function of mice (n =40) was evaluated with ultrasound 6 hours after LPS administration.Subsequently,the tissues of heart,lung and kidney of mice (n =6) were taken and treated with Haematoxylin -Eosin staining (H&E) in order to observe the pathological changes and verify the successfulness of modeling.Immunohistochemistry staining with PECAM - 1 and α - SMA was used to identify the angiogenesis in the heart ( n =3 ),while the TUNEL apoptosis assay was applied for detecting the myocardial cell apoptosis ( n =3 ).The mRNA was extracted from heart tissue (n =6) to observe the expression of HIF-1 ot which was proved to be an angiogenesis factor.All the results were analyzed by independent sample t - test.Results Compared to the control group,mice in the sepsis group showed increased in thickness of left ventricular diastolic anterior wall ( t =- 4.60,P ＜ 0.05 ) and thickness of left ventricular systolic anterior wall (t =-3.24,P ＜0.05 ) along with decrease in left ventricular end diastolic diameter ( t =3.57,P ＜ 0.01 ) and stroke volume ( t =5.51,P ＜ 0.01 ).Immunohistochemistry staining with alpha - SAM antibody revealed increase in cardiac angiogenesis in the sepsis group (t =- 11.00,P ＜ 0.01 ).TUNEL apoptosis assay demonstrated apoptosis of the cardiomyocytes [ sepsis group versus control group:( 191.31 ±5.41 ) vs ( 52.24 ±4.32) ] and RT - PCR showed an increase in the expression of HIF - 1 alpha in the mice of the sepsis group ( t =- 8.12,P ＜0.05) Conclusions There were apparent myocardial angiogenesis,apoptosis and cardiac dysfunction in septic animal models.HIF-1α might play a role in the angiogenesis pathway.