The changes of angiotensin Ⅱ and its receptors in lipopolysaccharide-induced acute lung and kidney injury in rats / 中国小儿急救医学

ABSTRACT

Objective:To investigate the expression and significance of the angiotensin Ⅱ and its receptors in lipopolysaccharide (LPS)-induced acute lung injury and acute kidney injury in rats.Methods:Forty eight Wistar rats were randomly divided into two groups control group and endotoxin group (LPS group). LPS was injected through tail vein in LPS group, and the same amount of saline was injected through tail vein in control group.Samples were collected at 2 h, 6 h, 12 h and 24 h, respectively.The histopathology of lung and kidney was observed by HE staining.We detected lung wet/dry weight ratio, serum creatinine, urea nitrogen and Ang Ⅱ concentration in plasma, lung and kidney tissues by radioimmunoassay.Western blot and immunohistochemistry were used to detect the expression changes of AT1R and AT2R in lung and kidney tissue.Results:Compared with the control group, the pathology of lung and kidney tissue in LPS group showed different degrees of damage.The lung wet/dry weight ratio, serum creatinine and urea level in LPS group were significantly increased than that in control group( P<0.05). The Ang Ⅱ content in plasma increased significantly at 2 h and 6 h ( P<0.05), and the expression level of Ang Ⅱ in lung and kidney increased significantly at all time points ( P<0.05). The expression of AT1R in lung and kidney decreased significantly ( P<0.05), while the AT2R protein expression increased significantly ( P<0.05). Additionally the correlation analysis showed that the expression level of Ang Ⅱ and AT2R were positively correlated with lung and renal function, while the expression of AT1R was negatively correlated with lung and renal function. Conclusion:LPS results in the damage of lung and kidney function and the change of renin-angiotensin system.The changes of Ang Ⅱ and angiotension receptors were correlated with lung and kidney injury.Ang Ⅱ and angiotension receptors may be involved in LPS induced lung and kidney injury.