探讨利多卡因对脓毒症大鼠肺损伤及炎症因子表达的影响。

采用随机数字表法将60只雄性成年Sprague Dawley大鼠分为假手术组、盲肠结扎穿孔（CLP）组、利多卡因组和乌司他丁组，每组各15只。假手术组大鼠打开腹腔后缝合，其他各组采用CLP法制备脓毒症模型。利多卡因组大鼠在给予10 mg/kg的负荷剂量后，以10 mg·kg^-1·h^-1的剂量通过尾静脉持续泵注利多卡因3h；乌司他丁组大鼠进行CLP的同时，以100 000 U·kg^-1·h^-1的剂量通过尾静脉持续泵注乌司他丁3 h；假手术组和CLP组用等量等渗NaCl溶液代替。于CLP后24 h处死大鼠，采用酶联免疫吸附实验（ELISA）法测定血清中肿瘤坏死因子α（TNF-α）、白细胞介素6（IL-6）及高迁移率族蛋白B1（HMGB1）表达水平；实时荧光定量PCR检测肺组织HMGB1 mRNA表达水平；苏木素-伊红（HE）染色法观察各组大鼠肺组织病理变化。另取40只大鼠（每组10只）用于观察4组大鼠72 h死亡情况。

4组大鼠血清中TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平比较，差异均有统计学意义（F = 189.886、237.952、175.999、179.491，P均< 0.001）。进一步两两比较发现，与假手术组比较，CLP组、利多卡因组和乌司他丁组血清TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平均显著升高（P均< 0.05）；与CLP组比较，利多卡因组和乌司他丁组血清TNF-α、IL-6、HMGB1及HMGB1 mRNA表达水平均显著降低（P均< 0.05）；与利多卡因组比较，乌司他丁组IL-6表达水平显著升高（P < 0.05）。HE染色结果显示，假手术组大鼠肺泡大小均匀、结构完整，肺泡上皮细胞形态正常；CLP组大鼠肺泡间隔增厚、间质充血水肿、炎症细胞浸润、肺泡塌陷；而利多卡因组和乌司他丁组病理学改变较CLP组均明显减轻，肺组织轻度水肿，肺泡及肺间质出现少量炎症。四组大鼠死亡构成比（0 /10、9/1、4/6、3/7）比较，差异有统计学意义（χ²=17.500，P < 0.001）。CLP组、利多卡因组和乌司他丁组大鼠死亡构成比均较假手术组显著升高（P均<0.008）；利多卡因组和乌司他丁组大鼠死亡构成比均较CLP组显著降低（P均<0.008）；而利多卡因组和乌司他丁组大鼠死亡构成比比较，差异无统计学意义（P > 0.008）。

持续静脉泵注利多卡因可以有效降低脓毒症大鼠炎症因子TNF-α、IL-6及HMGB1的表达，抑制肺组织中HMGB1 mRNA表达量，减轻脓毒症对肺组织的损伤，有效提高动物存活率，其减轻脓毒症炎症反应及肺保护作用疗效与乌司他丁相似。

To investigate the effect of lidocaine on lung injury and expression of inflammatory factors in septic rats.

Sixty male adult Sprague Dawley rats were randomly divided into the sham operation group, cecal ligation and puncture (CLP) group, ulinastatin group and lidocaine group, with 15 rats in each group. The abdominal cavity of rats was opened and sutured in the sham operation group, and sepsis models in the other groups were established by the CLP method. Rats in the lidocaine group were continuously pumped with lidocaine through the tail vein at a dose of 10 mg·kg^-1·h^-1 for 3 h after injecting a loading dose of 10 mg/kg. Rats in the ulinastatin group were given CLP and continuously pumped with ulinastatin through the tail vein at a dose of 100 000 U·kg^-1·h^-1 for 3 h. Rats in the sham operation and CLP groups were injected with equal amount of isoosmotic NaCl solution. The levels of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and high mobility group box 1 (HMGB1) in serum were determined by enzyme-linked immunosorbent assay (ELISA), as all rats were sacrificed at 24 h after CLP. The expression of HMGB1 mRNA in lung tissue was detected by real-time fluorescence quantitative PCR, and the pathological changes of lung tissue in each group were observed by hematoxylin-eosin (HE) staining. Another 40 rats (10 in each group) were used to observe the death condition at 72 h in 4 groups.

The levels of TNF-α, IL-6, HMGB1, and HMGB1 mRNA in serum of the four groups were significantly different (F=189.886, 237.952, 175.999, 179.491; all P < 0.001). Further pairwise comparison showed that the levels of serum TNF-α, IL-6, HMGB1, and HMGB1 mRNA in the CLP, lidocaine and ulinastatin groups were significantly higher than those in the sham operation group (all P < 0.05). Compared with the CLP group, the levels of TNF-α, IL-6, HMGB1, and HMGB1 mRNA were significantly lower in the lidocaine and ulinastatin groups (all P < 0.05). Compared with the lidocaine group, the IL-6 level was significantly higher in the ulinastatin group (P < 0.05). The HE staining showed uniform alveoli with intact structure and normal alveolar epithelial cells of rats in the sham operation group. Alveolar septum thickening, interstitial congestion and edema, inflammatory cell infiltration and alveolar collapse were found in the CLP group. However, the pathological changes in the lidocaine and ulinastatin groups were significantly less than those in the CLP group; the lung tissue was mildly edematous, and a small amount of inflammation appeared in alveoli and pulmonary stroma. The proportional mortality indicator (0/10, 9/1, 4/6, 3/7) was significantly different among the four groups (χ²=17.500, P < 0.001). It was significantly higher in the CLP, lidocaine and ulinastatin groups than in the sham operation group (all P < 0.008). It was significantly lower in the lidocaine and ulinastatin groups than in the CLP group (both P < 0.008), and there was no significant difference in the proportional mortality indicator between the lidocaine and ulinastatin groups (P > 0.008).

By reducing the expressions of TNF-α, IL-6 and HMGB1 and inhibiting the HMGB1 mRNA expression in lung tissue, continuous intravenous injection of lidocaine can alleviate pulmonary injury induced by sepsis and effectively improve the survival rate. The effect of lidocaine on inflammatory reaction and lung protection after sepsis is similar to that of ulinastatin.