肠内营养和淋巴干结扎在肠道缺血再灌注损伤中的作用

Effect of enteral nutrition and lymph duct ligation on intestine ischemia-reperfusion injury

目的观察大鼠肠道缺血再灌注损伤时肠内营养及淋巴干结扎对肠道功能及远隔组织的影响。方法40只雄性SD大鼠，胃造瘘后随机分为5组：A1组普通饮食（N）；A2组普通饮食和淋巴干结扎（N＋L）；B1组肠内营养（EN）；B2组肠内营养和淋巴干结扎（EN＋L）；C组假手术组（Sham）。肠内营养或普通饮食的大鼠在7d后行肠道淋巴干结扎和缺血（60min）再灌注（72h）（I／R）。结果I／R 72h时各组体质量较造瘘前显著下降（N11．25g；N＋L21．13g；EN21．38g；EN＋L23．88g；Sham10．88g，P〈0．05）；在普通饮食和肠内营养组中淋巴干结扎与不结扎组之间空肠黏膜厚度和绒毛高度差异无统计学意义（P〉0．05），但结扎组比不结扎组都有增高的趋势。肠内营养组回肠黏膜厚度在淋巴干结扎和不结扎组之间的差异有统计学意义[EN／EN＋L为（474．52±59．11）／（539．06±58．62）um，P〈0．05]；各组在I／R24h时肠道通透性显著升高，与缺血前比较差异有统计学意义（分别增加N2．29；N＋L4．04；EN0．96；EN＋L1．70；Sham1．04，P〈0．05）。I／R72h时L／M都不同程度的下降。EN＋L下降差异有统计学意义（2411／72h，2．98／1．81，P〈0．05）；各组的二胺氧化酶、D-乳酸、内毒素和细胞因子及肺组织一氧化氮（NO）、一氧化氮合酶（tNOS）、诱导型一氧化氮合酶（iNOS）和髓过氧化物酶（MPO）水平在淋巴干结扎与不结扎之间差异无统计学意义（P〉0．05），但是淋巴干结扎组较不结扎组比较都有不同的降低趋势。结论肠道缺血再灌注损伤可引起体质量下降和肠道通透性增加；淋巴干结扎后在缺血再灌注72h时内毒素、二胺氧化酶、D-乳酸等有下降趋势，但与不结扎组比较差异无统计学意义，可能与大鼠缺血后经过3d时间，部分指标已自行恢复有关。

Objective To investigate the effect of enteral nutrition and lymph duct ligation on rat intestine ischemia-reperfusion injury. Methods Forty healthy male SD rats of SPF grade were randomly divided into 5 groups （n = 8 in each group） after gastrostomy：A1, normal diet group （N） ;A2, normal diet and lymph duct ligation group （N ＋ L） ;B1 ,enteral nutrition group （EN） ;B2 enteral nutrition and lymph duct ligation group （EN ＋ L） ;C, control group （Sham）. After enteral nutrition or normal diet for 7 days, rats underwent mesenteric lymph duct ligation and intestine ischemia-reperfusion injury （ ischemia for 60 min, followed by reperfusion for 72 h）. Results The body weight of every group was significantly reduced after gastrostomy （ N 11.25 g; N ＋ L 21.13 g; EN 21.38 g; EN ＋ L 23.88 g; Sham 10.88 g, P 〈 0.05 ）. The mucous thickness and villus height of jejunum had no significant difference among all groups （ P 〉 0.05）, but the ileum had significant difference between EN group and EN ＋ L group [ EN/EN ＋ L （474.52 ± 59.11 ）/（539.06 ± 58.62） um P 〈 0.05 ]. The L/M value at the first day after intestine ischemia-reperfusion was increased significantly in all groups as compared with that before intestine ischemia-reperfusion （ N 2.29 ; N ＋ L 4.04 ; EN 0.96 ; EN ＋ L 1.70 ; Sham 1.04, P 〈 0.05 ）. The IZM value at the 3rd day after intestine ischemia-reperfusion was decreased to varying degrees, and significant decrease was found in EN ＋ L group （24 h/72 h,2.98/1.81, P 〈 0.05 ）. The DAO, D-lactic acid, endotoxin and cytokines in serum and the NO, NOS, iNOS and MPO in lung tissue had no significant difference among groups （P 〉 0.05）, but there was a decreasing trend in both ligation groups. Conclusion Intestine ischemia- reperfusion injury caused body-weight loss and increased intestine permeability. The endotoxin, DAO and D-lactic acid had a downtrend in N ＋ L and EN ＋ L groups at the 72nd h after ischemia/reperfusion following lymph duct ligation,but they had no significant difference with no-ligation group,which may be related to the recovery of some indications in rats 3 days after intestine ischemia-reperfusion.