Klausner J M, Paterson I S, Kobzik L, Valeri C R, Shepro D, Hechtman H B
Department of Surgery, Brigham and Women's Hospital, Boston, MA 02115.
Ann Surg. 1989 Apr;209(4):462-70. doi: 10.1097/00000658-198904000-00012.
Reperfusion after limb ischemia leads to sequestration of polymorphonuclear leukocytes (PMN) in the lungs and to leukocyte- (WBC) and thromboxane- (Tx) dependent respiratory dysfunction. This study examines the intermediary role of the chemoattractants leukotriene (LT)B4 and complement (C) fragments. Anesthetized sheep with chronic lung lymph fistulae underwent 2 hours of tourniquet ischemia of both hind limbs. In untreated controls (n = 7), 1 minute after tourniquet release, mean pulmonary artery pressure (MPAP) rose from 13 to 38 mmHg (p less than 0.05) and returned to baseline within 30 minutes. Pulmonary artery wedge pressure was unchanged from 3.6 mmHg. There were increases in plasma LTB4 levels from 2.46 to 9.34 ng/ml (p less than 0.01), plasma TxB2 levels from 211 to 735 pg/ml (p less than 0.05), and lung lymph TxB2 from 400 to 1005 pg/ml (p less than 0.05). C3 levels were 96% of baseline values. Thirty minutes after reperfusion, lung lymph flow (QL) increased from 4.3 to 8.3 ml/30 minutes (p less than 0.05), lymph/plasma protein ratio was unchanged from 0.6, and the lymph protein clearance increased from 2.6 to 4.6 ml/30 minutes (p less than 0.05), data consistent with increased microvascular permeability. WBC count fell within the first hour from 6853 to 3793/mm3 (p less than 0.01). Lung histology showed leukosequestration, 62 PMN/10 high-power fields (HPF) and proteinaceous exudates. In contrast to this untreated ischemic group, animals treated with the lypoxygenase inhibitor diethylcarbamazine (n = 5) demonstrated a blunted reperfusion-induced rise in MPAP to 17 mmHg (p less than 0.05). There were no increases in LTB4, TxB2, QL or lymph protein clearance (p less than 0.05). WBC count was unchanged and lung leukosequestration was reduced to 40 PMN/10 HPF (p less than 0.05). Decomplementation with cobra venom factor (n = 4) resulted in plasma C3 levels, 10% of baseline, but tourniquet release still led to pulmonary hypertension, elevated LTB4, TxB2 levels, and a decline in WBC count similar to that of untreated ischemic control animals. Histology showed 46 PMN/10 HPF sequestered in the lungs. Further, bilateral hind limb ischemia in either genetically sufficient (n = 10) or deficient (n = 10) C5 mice led to significant lung leukosequestration of 108 and 106 PMN/10 HPF, respectively, compared with 42 and 47 PMN/10 HPF in sham C5(+) and C5 (-) mice (n = 20) (p less than 0.01). These results suggest that the lung leukosequestration and increased microvascular permeability after lower torso ischemia are mediated by the chemotactic agent LTB4, but not by the complement system.
肢体缺血后的再灌注会导致多形核白细胞（PMN）在肺部滞留，并导致白细胞（WBC）和血栓素（Tx）依赖性呼吸功能障碍。本研究探讨趋化因子白三烯（LT）B4和补体（C）片段的中介作用。对患有慢性肺淋巴瘘的麻醉绵羊的双后肢进行2小时的止血带缺血处理。在未治疗的对照组（n = 7）中，止血带松开后1分钟，平均肺动脉压（MPAP）从13 mmHg升至38 mmHg（p < 0.05），并在30分钟内恢复至基线水平。肺动脉楔压从3.6 mmHg未发生变化。血浆LTB4水平从2.46 ng/ml升至9.34 ng/ml（p < 0.01），血浆TxB2水平从211 pg/ml升至735 pg/ml（p < 0.05），肺淋巴TxB2从400 pg/ml升至1005 pg/ml（p < 0.05）。C3水平为基线值的96%。再灌注30分钟后，肺淋巴流量（QL）从4.3 ml/30分钟增加至8.3 ml/30分钟（p < 0.05），淋巴/血浆蛋白比值从0.6未发生变化，淋巴蛋白清除率从2.6 ml/30分钟增加至4.6 ml/30分钟（p < 0.05），这些数据与微血管通透性增加一致。白细胞计数在第一小时内从6853/mm³降至3793/mm³（p < 0.01）。肺组织学显示白细胞滞留，每10个高倍视野（HPF）有62个PMN以及蛋白质渗出物。与未治疗的缺血组相比，用脂氧合酶抑制剂乙胺嗪治疗的动物（n = 5），再灌注诱导的MPAP升高减弱至17 mmHg（p < 0.05）。LTB4、TxB2、QL或淋巴蛋白清除率均未增加（p < 0.05）。白细胞计数未发生变化，肺白细胞滞留减少至每10个HPF有40个PMN（p < 0.05）。用眼镜蛇毒因子进行补体灭活（n = 4）导致血浆C3水平降至基线的10%，但止血带松开仍导致肺动脉高压、LTB4和TxB2水平升高以及白细胞计数下降，与未治疗的缺血对照动物相似。组织学显示每10个HPF有46个PMN滞留在肺部。此外，与假手术的C5(+)和C5(-)小鼠（n = 20）每10个HPF分别有42个和47个PMN相比，基因充足（n = 10）或缺乏（n = 10）C5的小鼠双侧后肢缺血分别导致显著的肺白细胞滞留，每10个HPF分别有108个和106个PMN（p < 0.01）。这些结果表明，下半身缺血后肺白细胞滞留和微血管通透性增加是由趋化剂LTB4介导的，而非补体系统。
