[Effects of angiotensin-(1-7) on oxidative stress and functional changes of isolated rat hearts induced by ischemia-reperfusion].
OBJECTIVE
To investigate the effects of angiotensin (Ang)-(1-7) on oxidative stress and functional changes in isolated rat hearts with myocardial ischemia-reperfusion (IR) injury.


METHODS
IR injury was induced in isolated rat hearts with the Langendorff' apparatus. The left ventricular systolic pressure (LVSP) of the rat heart was measured using a pressure transducer. Malondialdehyde (MDA) level and superoxide dismutase (SOD) activity in the myocardium were detected using commercial kits.


RESULTS
Myocardial ischemia (15 min) and reperfusion (30 min) significantly increased myocardial levels of MDA, and reduced the SOD activity and LVSP (P<0.05). Pretreatment with Ang-(1-7) at 1.0 nmol/L 30 min before ischemia obviously inhibited IR-induced MDA increment and lowering of SOD activity and LVSP. Pretreatment of the rats with intraperitoneal injection of 5 mg/kg indomethacin 1 h before isolation of the heart markedly antagonized the effect of Ang-(1-7) on MDA production, SOD activity and LVSP.


CONCLUSIONS
Angiotensin-(1-7) can inhibit IR injury-induced oxidative stress and decrease in cardiac contractile function in isolated rat hearts. The mechanism underlying the effect of Ang-(1-7) may be associated with increased secretion of prostaglandin.
Liao
Xin-xue
XX
Department of Cardiology, Zhongshan Medical College, Sun Yat-sen University, Guangzhou, China. liaoxinx@mail.sysu.edu.cn
Guo
Rui-xian
RX
Ma
Hong
H
Wang
Li-chun
LC
Chen
Zheng-hua
ZH
Yang
Chun-tao
CT
Feng
Jian-qiang
JQ