高原地区大鼠烫伤延迟复苏后Peyer氏结中Bax表达及其意义

目的：探讨不同海拔高度大鼠烫伤延迟复苏后回肠Peyer氏结淋巴细胞凋亡和Bax基因表达的意义。方法：Wistar大鼠132只，分别在海拔1517m和3848m随机分为延迟复苏组（DFR）、即时复苏组（IFR）和假伤组（SG），建立TBSA 30％Ⅲ度烫伤模型，分别于伤后6、12、24、48和72h取材。采用TUNEL、免疫组化与图象分析技术，观察Peyer氏结中淋巴细胞凋亡率及Bax表达。结果：淋巴细胞凋亡率在各海拔高度DFR组和IFR组均高于SG组，随海拔高度上升凋亡率有所上升；DFR组凋亡率高于同海拔IFR组，海拔3848m各实验组分别高于海拔1517m（P〈0．05）；Bax表达强度变化平行于淋巴细胞凋亡率变化，但在伤后6h和72h海拔3848m各实验组分别高于海拔1517m（P〈0．05）。结论：高原地区烫伤延迟复苏后Bax表达增高可能是Peyer氏结T淋巴细胞凋亡增加的重要原因之一。

Bax expression of lymphocyte in the Peyer's patches after burn with delayed fluid resuscitation in rats at high altitude

Objective ：To explore the significance of Bax expression and apoptosis of lymphocyte in ileal Peyer＇s patches after severe burn with delayed fluid resuscitation at different altitude in rats. Methods： 132 Wistar rats were employed as the experimental models （TBSA30% , Ⅲ degree） , and they were randomly divided into 3 groups at different altitude respectively： delayed fluid resuscitation group （DFR） , immediate fluid resuscitation group （IFR） and sham group （SG） . The Peyer＇s patches were harvested from the ileum of rats at 6 b, 12 h, 24 h, 48 b and 72 h after burn. The apoptosis rate and the Bax expression in Peyer＇s patches were detected by TUNEL, tissue microarray technology and immunohistochemistry. Results： The apoptosis rate of lymphocyte was much higher in DFR and IFR than that in SG with the increase of altitude. The apoptosis rate enhanced significantly at 3 848 m than that at 1 517 m, and in DFR than that in IFR. The trend of Bax expression was as same as the change of the apoptosis rate of lymphocyte, and was higher at 3 848 m than that at 1 517 m at 6 h and 72 h after injury in experimental groups （P 〈 0.05 ）. Conclusion： The Bax overexpression may be responsible for the high apoptosis rate of lymphoeytes in Peyer＇s patches after severe burn with delayed fluid resuscitation in rats at high altitude.