[Effect of different tidal volume ventilation on apoptosis and the expression of Bax and Bcl-2 in rat lungs].
OBJECTIVE
To determine the effect of different tidal volume(Vt) ventilation on apoptosis and the expression of Bax and Bcl-2 in rat lungs.


METHODS
Twenty-four healthy SD rats were randomly divided into 4 groups: a control group, a low Vt ventilation group (LV), a middle Vt ventilation group (MV), and a high Vt ventilation group (HV). Rats were subjected to different tidal volumes (10,20,and 40 mL/kg) for 2 h except the control group, which kept their own breath. We determined the lung histopathology score, W/D ratio and WBC in bronchoalceolar lavage fluid (BALF) to evaluate the lung injury and examine the apoptotic cell death, Bax and Bcl-2 protein expression by using TUNEL technique and immunohistochemistry 24 h after the operation.


RESULTS
Compared with the control group, MV and HV increased lung histopathology score, W/D ratio, WBC in BALF, apoptosis index (AI )and Bax protein expression, but decreased Bcl-2 protein expression (P<0.05). These changes showed no significant difference between the control group and the low Vt ventilation group (P>0.05).


CONCLUSIONS
Low Vt ventilation contributed little to apoptosis. Higher Vt ventilation can improve Bax while inhibit Bcl-2 expression to aggravate apoptosis in rat lungs.
Wang
Xi
X
Department of Anesthesiology, Xiangya Hospital, Changsha 410008, China.
Cai
Hongwei
H
Yan
Xia
X
Ye
Zhi
Z
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D005260:Female; D008168:Lung / Q000473:pathology*; D008297:Male; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000379:methods; D013990:Tidal Volume / Q000502:physiology; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
C494828:Bax protein, rat; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein