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H_(2)S protects myocardium against ischemia/reperfusion injury and its effect on c--Fos protein expression in rats

Zhu Xiaoying, Yan Xiaohong, Chen Shijian

Department of Physiology, School of Basic Medicine, Wuhan University.Wuhan 430071,Hubei

Abstract

The present study was aimed to study the effect of hydrogen sulfide (H_(2)S) on rat myocardial ischemia/reperfusion (I/R)injury and whether the effect is mediated by c-Fos protein expression. Male Sprague-Dawley rats were randomly divided into 4 groups:Control group: sham treatment; I/R group: the rat anterior descending branch of left coronary artery was occluded for 30 min and thenreleased to allow reperfusion for 60 min; Naris (exogenous H_(2)S donor) groups: the rats were pretreated with NaHs at 2.8 #mu#mol/kg bodyweight and 14 #mu#mol/kg body weight (i.v.), respectively, before I/R treatment. Hemodynamics (LVSP, LV±dp/dt_(max)) and electrocardio-gram (ECG, lead Ⅱ) were monitored continuously with multi-channel physiological signal analysis system after reperfusion. Myocar-dial infarct size was measured using triphenyltetrazolium chloride (TTC) staining. H_(2)S concentration in the plasma was determinedwith a spectrophotometer. Morphological and ultrastructural changes in myocardial tissue wereevaluated by HE staining and by atransmission electron microscope. The evaluation of c-Fos protein expression in myocardial tissue was performed by immunohistological staining. The results showed that H_(2)S concentration in rat plasma in I/R group was significantly decreased compared with that in thecontrol group [(30.32±5.26) vs (58.28±7.86) #mu#mol/L, P<0.05]. NaHs at 2.8 and 14 #mu#mol/kg body weight reduced the changes in LVSP,LV±dp/dt_(max) in rat myocardium induced by I/R injury. The values of LVSP, +dp/dt_(max) and -dp/dt_(max) at 60 min during myocardialreperfusion were enhanced from (75.93±1.10)%, (66.27±4.78)% and (66.01±4.79)% in I/R group to (84.34±2.24)%, (76.38±1.93)% and (75.47±5.29)% in 2.8 #mu#mol/kg body weight NaHs group (P<0.05, P<0.01, n=6), (88.40±2.88)%, (80.10±2.09)% and(80.48±6.20)% in 14 #mu#mol/kg body weight NaHS group (P<0.01, n=6), respectively. Compared with that in 2.8 #mu#mol/kg body weight NaHs group, the enhancing effect was more prominent in 14 #mu#mol/kg body weight NaHs group. NaHS at 14 #mu#mol/kg body weightmarkedly alleviated the injury in morphological changes and decreased c-Fos protein expression in myocardial tissue compared withthat in I/R group (0.20±0.06 vs 0.32±0.10, P<0.05). These results suggest that H_(2)S protects myocardium against I/R injury and thisprotective effect may be related to the down-regulation of c-Fos protein expression.

Key words: hydrogen sulfide;ischemia/reperfusion injury;c-Fos protein;myocardium

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Citing This Article：

Zhu Xiaoying, Yan Xiaohong, Chen Shijian. H_(2)S protects myocardium against ischemia/reperfusion injury and its effect on c--Fos protein expression in rats. Acta Physiol Sin 2008; 60 (2): 221-227 (in Chinese with English abstract).