沙漠干热环境腹部肠管火器伤后肝脏COX-2的表达与肝细胞凋亡的关系研究

目的：探讨沙漠干热环境下猪腹部肠管火器伤后肝脏环氧化酶-2（COX-2）的表达与肝细胞凋亡之间的关系。方法：沙漠干热环境组和常温环境组各42头长白仔猪随机等分为对照组和伤后1h、2h、4h、8h、12h和24h组7个时间组，实验各组在建立腹部肠管火器伤模型后，用免疫组化图像分析法测定各组肝组织COX-2的表达，采用TUNEL法观察肝细胞凋亡情况，并检测血清ALT的变化。结果：沙漠干热环境组和常温环境组中各实验组COX-2表达水平及肝细胞凋亡率均明显高于对照组（P〈0．01）；在沙漠干热环境组，各实验组肝脏COX-2表达水平明显高于相对应的常温组（P〈0．01），肝细胞凋亡率在1h、2h、4h、8h明显高于相对应的常温组（P〈0．05或P〈0．01）；肝脏COX-2的表达水平和肝细胞凋亡率在沙漠干热环境组和常温组中的第1个高峰值均出现在伤后2h组，沙漠干热环境组的第2个高峰值出现在伤后8h组，而常温环境组的第2个高峰出现在伤后12h组；血清ALT的变化趋势与COX-2的表达及细胞凋亡的趋势相似，肝脏COX-2表达水平和肝细胞凋亡率在沙漠干热环境组和常温环境组均具有相关性，相关系数分别为0．973和0．945，（P〈0．01）。结论：沙漠干热环境腹部肠管火器伤后肝脏COX-2的水平明显高于常温组，COX-2的表达与肝细胞凋亡的变化趋势一致，且密切相关，提示在沙漠干热环境腹部肠管火器伤后COX-2可能通过促进肝细胞凋亡在继发性肝脏损害过程中起重要作用。

Expression of Hepatic COX-2 and Hepatocyte Apoptosis in Pigs after Intestinal Firearm Wound in Hot and Dry Desert Environment

Objective： To investigate the expressions of hepatic COX-2 and apoptosis in pigs aider intestinal firearm wound in dry heat environment of desert. Methods： A total of 84 Chang-Bai piglets were equally divided randomly into dry heat environment group and normal environment group, and each group were divided into 7 group： control group and wounded lh group, 2h group, 4h group, 8h group, 12h group, 24h group. The model of intestinal perforations due to abdominal firearm wound was established in wounded groups. Paraffin-embedded liver sections were assayed for Hepatic COX-2 expression and measured with immunohistochemical staining and im- age analysis in all groups, apoptosis was assayed using the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling （TUNEL） assay. Results： Levels of hepatic COX-2 expressions and hepatocellular apoptosis indexes in wounded groups were significantly elevated compared to control group in both environment groups （P〈0.01）, Levels of hepatic COX-2 expressions in wounded groups of dry heat environment group were significantly elevated compared to the corresponding same time group of normal environment （P〈0.01）. hepatocellular apoptosis indexes in lh,2h,4h,8h groups of of dry heat environment group were significantly elevated compared to the corresponding same time group of normal environment （P 〈0.05 or P 〈0.01 ）. Both levels of hepatic COX-2 expressions and hepatoceUular apoptosis indexes reached their first peak at 2h group in both environment groups; however, they reached their second peak at different time group, which was at 8h goup for the dry heat environment group and 12h group for the normal normal environment group. Serum ALT had the similar changing trend as the levels of hepatic COX-2 expressions and hepatocellular apoptosis. Levels of hepatic COX-2 expressions and hepatocellular apoptosis indexes correlated with each other significantly both in dry heat envi- ronment and in normal environment, correlated ratio were 0.973 and 0.945 （P〈0.01）,respectively. Conclusion： Levels of hepatic COX-2 expressions in wounded groups of dry heat environment group were significantly elevated compared to the corresponding same time group of normal environment. Levels of hepatic COX-2 expressions and hepatocellular apoptosis indexes had the same changing tendency in dry heat environment and in normal environment, and they intimately correlated each other, suggested that COX-2 may through promoting hepatocellular apoptosis which play a important role in secondary liver injury after intestinal firearm wound in dry heat environment of desert.