The role of angiogenesis in myocardial injury in septic mice / 中华急诊医学杂志

ABSTRACT

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.