肠内营养对慢性阻塞性肺疾病模型大鼠的肠黏膜屏障的影响

目的：探讨肠内营养（EN）能否改善COPD的肠黏膜屏障。方法采用随机表法将35只大鼠分为空白对照组（K组，n＝10只）、COPD组＋EN组（n＝25只）。对COPD组＋EN组共25只大鼠进行COPD模型制备，将COPD组＋EN组共19只大鼠再随机分为COPD组和EN组2组，第29天开始给予EN组EN混悬液喂养14d ，COPD组和K照组继续给予普通饮食，2周后测定各组大鼠的肺功能，采血检测丙二醛、二胺氧化酶，无菌条件下取肠系膜淋巴结行细菌培养，取回肠组织用光学显微镜测量黏膜厚度、隐窝深度、绒毛高度，用透射电镜观察小肠黏膜上皮细胞的微绒毛和细胞间的链接复合体，用免疫组织化学检测回肠黏膜固有层IgA＋浆细胞数量。结果 COPD组与EN组回肠黏膜厚度与 K 组相比均降低（528.92±59.32 v s 465.89±62.72、528.92±59.32 v s 393.52±72.64），而COPD组降低更明显（465.89±62.72 v s 393.52±72.64），差异有统计学意义（P＜0.05）。绒毛高度和隐窝深度在 K 组和 EN 组间比较（331.54±34.26 vs 308.76±20.08、143.17±24.29 vs 136.77±16.96），差异无统计学意义（P＞0.05），COPD组与EN组相比，绒毛高度和隐窝深度指标下降更明显（308.76±20.08 v s 249.93±33.42、114.50±11.44 v s 136.77±16.96），差异有统计学意义（P＜0.05）。EN组与K组细菌移位率差异无统计学意义（P＞0.05）， EN组比COPD发生细菌移位的概率低（ P＜0.05）。血清丙二醛及二胺氧化酶浓度在 K组与EN组之间比较（0.86±0.43vs1.318±0.29、7.46±1.78vs8.02±2.45），差异无统计学意义（P ＞0.05），而COPD组的血清丙二醛、二胺氧化酶浓度明显比EN组的浓度高（1.829±0.57vs1.318±0.29、11.10±3.23vs 8.02±2.45），差异有统计学意义（ P＜0.05）。EN组与K组相比肠黏膜固有层IgA＋浆细胞数均有所下降（40.50±3.95vs51.80±4.87），而COPD组下降更明显（34.11±6.29vs40.50±3.95），差异有统计学意义（P＜0.05）。结论 COPD会导致肠黏膜屏障的损伤， EN可以改善COPD的肠黏膜屏障。

Effect of enteral nutrition on intestinal mucosal barrier in COPD model rats

Objective To investigate whether enteral nutrition can improve the intestinal mucosal barrier in patients with chronic obstructive pulmonary disease (COPD) .Methods Thirty‐five rats were randomly divided into blank control group ( K group , n = 10 ) ,COPD group+ enteral nutrition ( EN ) group ( n = 25) .The established the COPD model of COPD group + EN group were divided into two groups as COPD group and EN group .From the 29th day ,began to feed the EN group enteral nutrition suspension for 14 days ,the rats of COPD group and K group were given normal diet .After 2 weeks ,took the blood serum to test malondialdehyde ,monoamine oxidase ,took the mesenteric lymph nodes under the bacteria free conditions to culture bacteria ,used the optical microscope to measure the thickness of the mucosa ,the depth of crypt and the height of villus ,observed the mucosal epithelial cell microvilli and intercellular links complex of intestinal by transmission electron microscope . The number of IgA tenplasma cells in the lamina of ieum mucosa was detected by immunohistochemistry .Results Compared with the K group ,the thickness of ileal mucosal of COPD group and the EN group decreased ( 528 .92 ± 59 .32 vs 465 .89 ± 62 .72 ,528 .92 ± 59 .32 vs 393 .52 ± 72 .64) ,and COPD group decreased more significantly (465 .89 ± 62 .72 vs 393 .52 ± 72 .64) ,the difference was statistically significant ( P<0 .05) , there is no significant difference in the height of villus and the depth of crypt between K group and EN group (331 .54 ± 34 .26 vs 308 .76 ± 20 .08 ,143 .17 ± 24 .29 vs 136 .77 ± 16 .96) ,the difference was not statistically significant ( P >0 .05) ,but COPD group was significantly lower ( P <0 .05) .There was no significant difference between EN group and K group in bacterial translocation ( P>0 .05) ,and EN group had a lower probability ( P < 0 .05) .About the serum concentration of MDA and DAO ,there was no statistical significance between the K group and EN group ( 0 .86 ± 0 .43 vs 1 .318 ± 0 .29 ,7 .46 ± 1 .78 vs 8 .02 ± 2 .45) ,the difference was not statistically significant ( P >0 .05) ,the serum levels of MDA and DAO concentration of the COPD group were significantly hihger than the EN group ( 1 .829 ± 0 .57 vs 1 .318 ± 0 .29 ,11 .10 ± 3 .23 vs 8 .02 ± 2 .45) ,the difference was statistically significant ( P <0 .05) .The number of IgA+ plasma cells in intestinal mucosa of the other two groups were lower than the K group (40 .50 ± 3 .95 vs 51 .80 ± 4 .87) ,while the COPD group was significantly lower than that in EN group (34 .11 ± 6 .29 vs 40 .50 ± 3 .95) ,the difference was statistically significant ( P < 0 .05) .Conclusions COPD can cause the damage of intestinal mucosal barrie ,enteral nutrition can mitigate the damage .