Objective To investigate the effects of recombinant human erythropoietin ( rHuEPO) on expressions of Bax and Bcl-2 proteins in hyperoxia-induced lung injury of adult rats.
Methods Fortyeight healthy male SD adult rats were randomly divided into six groups. The control group ( 0 h) breathed with room air. The rHuEPO intervention group was put into oxygen chamber and breathed with 100% O2 for 96 h plus intraperitoneal injection of rHuEPO (1000 U/kg) daily. Other four groups were put into oxygen chamber and breathed with 100% O2 for 24, 48, 72 and 96 h respectively. Arterial blood gases were measured to calculate oxygenation index. Wet-to-dry weight ratios of left lung were measured. The contents of TNF-α and IL-1β in bronchoalveolar lavage fluid (BALF) were assayed with radioimmunoassay. The expressions of Bax and Bcl-2 proteins in the lung were determined withWestern blot and immunohistochemisty. The changes of lung histopathology were assessed by hematoxylin and eosin stain and observed under light microscope.
Results After breathing 100% O2 , the oxygenation index decreased gradually and reached minimal value at 96 h. The wet-to-dry weight ratio of left lung increased gradually and reached maximal value at 96 h. The contents of TNF-α and IL-1β in BALF reached maximal value at 48 h and then decreased gradually. The expression of Bax protein increased, but the expression of Bcl-2 protein decreased gradually in the lung. Compared with the 96 h group, the oxygenation index was higher, wet-to-dry weight ratio and contents of TNF-α and IL-1β in BALF decreased, the expression of Bax protein decreased, and the expression of Bcl-2 protein increased in the lung of the rHuEPO group.
Conclusion rHuEPO can attenuate hyperoxia-induced lung injury of adult rats by down-regulating expression of Bax protein and up-regulating expression of Bcl-2 protein.
Citation： LIU Qinghui,LIU Changting,SHI Min,LIU Yan,YU Senyang. Effects of Recombinant Human Erythropoietin on Expression of Bax and Bcl-2 Proteins in Hyperoxia-Induced Lung Injury of Adult Rats. Chinese Journal of Respiratory and Critical Care Medicine, 2011, 10(4): 345-349. doi: Copy