Background: Ischaemic postconditioning (IPoC) has been shown to ameliorate ischaemia reperfusion injury in different species and tissues. Objectives: To assess the feasibility of IPoC in equine small intestinal ischaemia and to assess its effect on histomorphology, electrophysiology and paracellular permeability. Study design: randomized controlled terminal in vivo experiment Methods: Experimental jejunal ischaemia was induced for 90 min in horses under general anaesthesia. In the control group (C; n=7), the jejunum was reperfused without further intervention. In the postconditioning group (P; n=7), IPoC was implemented by clamping the mesenterial vessels after ischaemia. This was followed by 120 minutes of reperfusion in both groups. Intestinal microperfusion and oxygenation was measured during IPoC using spectrophotometry and Doppler fluxmetry. Histomorphology and histomorphometry of the intestinal mucosa were assessed. Furthermore, electrophysiological variables and unidirectional fluxrates of 3H-mannitol were determined in Ussing chambers. Western Blot analysis was performed to determine the tight junction protein levels of Claudin-1, Claudin-2 and Occludin in the intestinal mucosa. Comparisons between the groups and time points were performed using a two-way repeated measures ANOVA or non-parametric statistical tests for the ordinal and not normally distributed data (significance p<0.05). Results: Postconditioning significantly reduced intestinal microperfusion during all clamping cycles, yet affected tissue oxygenation only during the first cycle. After reperfusion, group IPoC showed significantly less mucosal villus denudation (mean difference 21.5 %, p=0.02) and decreased mucosal-to-serosal fluxrates (mean difference 15.2 nM/cm2/h, p=0.007) compared to group C. There were no significant differences between the groups for the other tested variables. Main limitations: small sample size, long term effects were not investigated. Conclusions: Following ischaemic postconditioning, the intestinal mucosa demonstrated significantly less villus denudation and paracellular permeability compared to the untreated control group, possibly indicating a protective effect of IPoC on ischaemia reperfusion injury.

中文翻译：

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缺血后处理对马空肠缺血黏膜完整性和功能的影响

背景：缺血后处理（IPoC）已被证明可以改善不同物种和组织的局部缺血再灌注损伤。目的：评估IPoC在马小肠缺血中的可行性，并评估其对组织形态学，电生理学和细胞旁通透性的影响。研究设计：随机对照终末体内实验方法：在全身麻醉下，在马中诱导实验性空肠缺血90分钟。在对照组（C； n = 7）中，无需进一步干预即可再次灌注空肠。在后处理组（P； n = 7）中，IPoC是通过在缺血后夹住肠系膜血管来实现的。两组均进行了120分钟的再灌注。在IPoC中使用分光光度法和多普勒通量法测量肠道微灌注和氧合。评估肠粘膜的组织形态学和组织形态学。此外，在Ussings室确定了3H-甘露醇的电生理变量和单向通量。进行蛋白质印迹分析以确定肠粘膜中Claudin-1，Claudin-2和Occludin的紧密连接蛋白水平。使用两次重复测量方差分析或非参数统计检验对顺序和非正态数据进行组和时间点之间的比较（显着性p <0.05）。结果：后处理在所有夹紧周期中均显着减少了肠道微灌注，但仅在第一个周期中才影响组织氧合。再灌注后，IPoC组的粘膜绒毛剥蚀明显减少（平均差异为21.5％，p = 0）。02）和与C组相比黏膜至浆膜通量降低（平均差异15.2 nM / cm2 / h，p = 0.007）。其他测试变量在各组之间无显着差异。主要局限性：样本量小，长期影响尚未调查。结论：缺血后处理后，与未治疗的对照组相比，肠粘膜表现出的绒毛剥落和细胞旁通透性显着降低，这可能表明IPoC对缺血再灌注损伤具有保护作用。