Nakao A, Moore B A, Murase N, Liu F, Zuckerbraun B S, Bach F H, Choi A M K, Nalesnik M A, Otterbein L E, Bauer A J
Thomas E Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA 15261, USA.
Gut. 2003 Sep;52(9):1278-85. doi: 10.1136/gut.52.9.1278.
Intestinal transplantation provokes an intense inflammatory response within the graft muscularis that causes intestinal ileus. We hypothesised that endogenously produced anti-inflammatory substances could be utilised as novel therapeutics. Therefore, we tested the protective effects of inhaled carbon monoxide (CO) and an endogenous haeme oxygenase 1 (HO-1) anti-inflammatory mediator on transplant induced inflammatory responses and intestinal ileus in the rat.
Gastrointestinal transit of non-absorbable FITC labelled dextran and in vitro jejunal circular muscle contractions were measured in controls and syngeneic orthotopic transplanted animals with and without CO inhalation (250 ppm for 25 hours). Inflammatory mRNAs for interleukin (IL)-6, IL-1beta, tumour necrosis factor alpha (TNF-alpha), intercellular adhesion molecule 1 (ICAM-1), inducible nitric oxide (iNOS), cyclooxygenase 2 (COX-2), and IL-10 were quantified by real time reverse transcriptase-polymerase chain reaction and HO-1 by northern blot. Histochemical stains characterised neutrophil infiltration and enterocyte apoptosis.
Transplantation delayed transit and suppressed jejunal circular muscle contractility. Transplantation induced dysmotility was significantly improved by CO inhalation. Transplantation initiated a significant upregulation in IL-6, IL-1beta, TNF-alpha, ICAM-1, iNOS, COX-2, and HO-1 mRNAs with the graft muscularis. CO inhalation significantly decreased expression of IL-6, IL-1beta, iNOS, and COX-2 mRNAs. CO also significantly decreased serum nitrite levels (iNOS activity).
CO inhalation significantly improved post-transplant motility and attenuated the inflammatory cytokine milieu in the syngeneic rat transplant model. Thus clinically providing CO, the end product of the anti-inflammatory HO-1 pathway, may prove to be an effective therapeutic adjunct for clinical small bowel transplantation.
肠道移植会在移植肠肌层引发强烈的炎症反应，导致肠梗阻。我们推测内源性产生的抗炎物质可作为新型治疗手段。因此，我们测试了吸入一氧化碳（CO）和内源性血红素加氧酶1（HO-1）抗炎介质对大鼠移植诱导的炎症反应和肠梗阻的保护作用。
在对照组以及同基因原位移植动物中，测量不可吸收的异硫氰酸荧光素（FITC）标记葡聚糖的胃肠转运以及体外空肠环行肌收缩，这些动物分为吸入CO组（250 ppm，持续25小时）和未吸入CO组。通过实时逆转录聚合酶链反应定量检测白细胞介素（IL）-6、IL-1β、肿瘤坏死因子α（TNF-α）、细胞间黏附分子1（ICAM-1）、诱导型一氧化氮合酶（iNOS）、环氧化酶2（COX-2）和IL-10的炎症相关mRNA，通过Northern印迹法检测HO-1。组织化学染色用于鉴定中性粒细胞浸润和肠上皮细胞凋亡。
移植导致胃肠转运延迟并抑制空肠环行肌收缩力。吸入CO可显著改善移植诱导的运动功能障碍。移植引发移植肠肌层中IL-6、IL-1β、TNF-α、ICAM-1、iNOS、COX-2和HO-1 mRNA显著上调。吸入CO可显著降低IL-6、IL-1β、iNOS和COX-2 mRNA的表达。CO还可显著降低血清亚硝酸盐水平（iNOS活性）。
在同基因大鼠移植模型中，吸入CO可显著改善移植后运动功能，并减轻炎症细胞因子环境。因此，临床上提供抗炎性HO-1途径的终产物CO可能被证明是临床小肠移植的一种有效治疗辅助手段。
