Harkin D W, Barros D'Sa A A, Yassin M M, Hoper M, Halliday M I, Parks T G, Campbell F C
Department of Surgery, The Queen's University of Belfast, Northern Ireland, UK.
J Vasc Surg. 2001 Apr;33(4):840-6. doi: 10.1067/mva.2001.111992.
Hind limb ischemia-reperfusion (I/R) injury increases gut permeability, and resultant endotoxemia is associated with an amplified systemic inflammatory response syndrome leading to multiple organ dysfunction syndrome. We studied the potential role of recombinant bactericidal/permeability-increasing protein (rBPI(21) ), a novel antiendotoxin therapy, in modulating endotoxin-enhanced systemic inflammatory response syndrome in hind limb I/R injury.
In this prospective, randomized, controlled, experimental animal study, 48 male Wistar rats, weighing 300 to 350 g, were randomized to a control group (sham) and five groups undergoing 3 hours bilateral hind limb ischemia with 2 hours reperfusion (I/R) (n = 8 per group). The control and untreated I/R groups received thaumatin, a control-protein preparation, at 2 mg/kg. Treatment groups were administered rBPI(21) intravenously at 1, 2, or 4 mg/kg body weight at the beginning of reperfusion; an additional group was administered rBPI(21) intravenously at 2 mg/kg after 1 hour of reperfusion. Plasma interleukin-6 concentration was estimated by bioassay as a measure of systemic inflammation. Plasma endotoxin concentration was determined by use of an amebocyte lysate chromogenic assay. Crossreactive immunoglobulin G and M antibodies to the highly conserved inner core region of endotoxin were measured by use of an enzyme-linked immunosorbent assay. The lung tissue wet-to-dry weight ratio and myeloperoxidase concentration were used as markers of edema and neutrophil sequestration, respectively.
I/R provoked highly significant elevation in plasma interleukin-6 concentrations (1351.20 pg/mL [860.16 - 1886.40 pg/mL]) compared with controls (125.32 pg/mL [87.76-157.52 pg/mL; P <.0001]), but treatment with rBPI(21) 2 mg/kg at onset of reperfusion (715.89 pg/mL [573.36-847.76 pg/mL]) significantly decreased interleukin-6 response compared with the nontreatment group ( P <.016). I/R increased plasma endotoxin concentrations significantly (21.52 pg/mL [6.20-48.23 pg/mL]), compared with control animals (0.90 pg/mL [0.00-2.30 pg/mL; P <.0001]), and treatment with rBPI(21) 4 mg/kg at reperfusion significantly decreased endotoxemia (1.30 pg/mL [1.20-2.20 pg/mL]), compared with the untreated group ( P <.001). The lung tissue myeloperoxidase level was significantly increased in the untreated I/R group (208.18% [128.79%-221.81%]), compared with in controls (62.00% [40.45%-80.92%; P <.0001]), and attenuated in those treated with rBPI(21) 2 mg/kg (129.54% [90.49%-145.78%; P <.05]). Data represent median and interquartile range, comparisons made with the nonparametric Mann-Whitney U test.
These findings show that hind limb ischemia-reperfusion injury is associated with endotoxemia, elevations in plasma interleukin-6, and pulmonary leukosequestration. Treatment with rBPI(21) after ischemia reduces endotoxemia, the interleukin-6 response, and attenuates pulmonary leukosequestration in response to hind limb reperfusion injury.
后肢缺血再灌注（I/R）损伤会增加肠道通透性，由此产生的内毒素血症与全身性炎症反应综合征加剧相关，进而导致多器官功能障碍综合征。我们研究了新型抗内毒素疗法重组杀菌/通透性增加蛋白（rBPI(21)）在调节后肢I/R损伤中内毒素增强的全身性炎症反应综合征方面的潜在作用。
在这项前瞻性、随机、对照实验动物研究中，将48只体重300至350 g的雄性Wistar大鼠随机分为对照组（假手术组）和五组进行3小时双侧后肢缺血并2小时再灌注（I/R）的组（每组n = 8）。对照组和未治疗的I/R组接受2 mg/kg的奇异果甜蛋白，一种对照蛋白制剂。治疗组在再灌注开始时分别以1、2或4 mg/kg体重静脉注射rBPI(21)；另一组在再灌注1小时后以2 mg/kg静脉注射rBPI(21)。通过生物测定法估算血浆白细胞介素-6浓度作为全身性炎症的指标。使用鲎试剂显色法测定血浆内毒素浓度。通过酶联免疫吸附测定法测量对内毒素高度保守的内核区域的交叉反应性免疫球蛋白G和M抗体。肺组织湿重与干重之比和髓过氧化物酶浓度分别用作水肿和中性粒细胞滞留的标志物。
与对照组（125.32 pg/mL [87.76 - 157.52 pg/mL]）相比，I/R导致血浆白细胞介素-6浓度显著升高（1351.20 pg/mL [860.16 - 1886.40 pg/mL]；P <.0001），但在再灌注开始时用2 mg/kg rBPI(21)治疗（715.89 pg/mL [573.36 - 847.76 pg/mL]）与未治疗组相比，显著降低了白细胞介素-6反应（P <.016）。与对照动物（0.90 pg/mL [0.00 - 2.30 pg/mL]；P <.0001）相比，I/R显著增加了血浆内毒素浓度（21.52 pg/mL [6.20 - 48.23 pg/mL]），再灌注时用4 mg/kg rBPI(21)治疗与未治疗组相比，显著降低了内毒素血症（1.30 pg/mL [1.20 - 2.20 pg/mL]；P <.001）。与对照组（62.00% [40.45% - 80.92%]；P <.0001）相比，未治疗的I/R组肺组织髓过氧化物酶水平显著升高（208.18% [128.79% - 221.81%]），而用2 mg/kg rBPI(21)治疗的组中该水平有所降低（129.54% [90.49% - 145.78%]；P <.05）。数据表示为中位数和四分位间距，采用非参数曼-惠特尼U检验进行比较。
这些发现表明后肢缺血再灌注损伤与内毒素血症、血浆白细胞介素-6升高和肺白细胞滞留有关。缺血后用rBPI(21)治疗可降低内毒素血症、白细胞介素-6反应，并减轻后肢再灌注损伤引起的肺白细胞滞留。
