摘要：
Objective To study the protective effect of pure carbachol or combined with dietary fiber on intestinal mucosal barrier of rats after diffuse brain injury (DBI).Methods An adult male Wistar rat model of DBI was reproduced by gravitational shock method. The rats injured and survived after resuscitation were divided into three groups: model group (n = 40), carbachol group (n = 40) and carbachol combined with dietary fiber group (combined group,n = 32). In addition, a control group was established by simply an incision performed on the scalp, and the rats could drink freely (n = 5). In the experimental groups, 2 hours after resuscitation the rats began to receive gavage, 6 hours once, the liquid amount 15 mL/kg should be assured in every 6 hours, and if insufficient, normal saline was supplemented. In model group, normal saline 90 mL/kg was given, in carbachol group, carbachol 300μg/kg was administered and in combined group, carbachol 300μg/kg combined with dietary fiber 60 mL/kg was supplied. At 3 (combined group being excluded), 6, 12, 24 and 48 hours after resuscitation, the rats were anesthetized to collect samples and detect the plasma levels of D-lactate and activity of diamine oxidase (DAO) respectively, and the changes of villus height of small intestine were examined by a light microscope.Results The plasma D-lactate levels and the activities of DAO at any time point in the experimental groups were significant higher than those in control group (allP < 0.01). Along with the prolongation of time, the levels of plasma D-lactate and DAO activities in carbachol and carbachol plus diatary fiber groups were gradually lower than those of the model group, and at 48 hours after injury they reached their valley values [D-lactate (ng/L): 6.32±0.79, 7.46±1.67 vs. 17.65±1.53, DAO activity (kU/L): 0.76±0.01, 0.86±0.01 vs. 2.23±0.15]. Under light microscopy, compared with control group, the villus height of small intestinal mucosa at any time point in any experimental group was gradually lowered, and reached the valley values at 12 hours, then gradually increased , and peaked at 48 hours, the villus height in carbachol group and combined group was higher than that in model group (μm: 265.36±10.20, 261.54±10.38 vs. 247.51±9.39, bothP < 0.05).Conclusion When only carbachol is administered into the rat intestine early after diffuse brain injury in rats, beginning from 6 hours after injury, the protective effect of intestinal mucosal barrier is shown, representing decrease of plasma D-lactate level and DAO activity, amelioration of intestinal mucosal damage and protection of intestinal mucosal barrier; under the same above situation, the carbachol combined with dietary fiber was applied, showing the similar above carbachol protective effects.%目的 观察单纯卡巴胆碱或卡巴胆碱联合膳食纤维对弥漫性脑损伤后肠屏障的影响,探讨其对肠屏障的保护作用.方法 采用重力打击法复制成年雄性Wistar大鼠弥漫性脑损伤模型,致伤并复苏存活的大鼠按处理方法不同分为模型组(n=40)、单纯卡巴胆碱组(n=40)、卡巴胆碱联合膳食纤维组(联合组,n=32).另设头皮切开对照组(n=5).各实验组从复苏后2 h开始灌胃,间隔6 h 1次,保证每6 h灌胃液体量为15 mL/kg,不足者加生理盐水.模型组给予生理盐水90 mL/kg;单纯卡巴胆碱组给予卡巴胆碱300μg/kg;联合组给予卡巴胆碱300μg/kg+膳食纤维60 mL/kg.分别于复苏后3(联合组除外)、6、12、24、48 h麻醉大鼠后取材,检测各组不同时间点血浆D-乳酸含量和二胺氧化酶(DAO)活性,光镜下观察小肠组织绒毛高度的改变.结果 各实验组各时间点血浆D-乳酸含量、DAO活性均较对照组明显升高,且差异有统计学意义(均P<0.01).随时间延长,单纯卡巴胆碱组和联合组D-乳酸含量和DAO活性均较模型组逐渐降低,于伤后48 h达谷值 〔D-乳酸(ng/L):6.32±0.79、7.46±1.67比17.65±1.53,DAO活性(kU/L):0.76±0.01、0.86±0.01比2.23±0.15〕.光镜下可见:与对照组比较,各实验组小肠组织绒毛高度呈现为逐渐下降,至12 h达最低,然后又逐渐升高至伤后48 h达最高值,单纯卡巴胆碱组和联合组均明显高于模型组(μm:265.36±10.20、261.54±10.38比247.51±9.39,均P<0.05).结论 弥漫性脑损伤后早期肠内给予卡巴胆碱从伤后6 h起即显示出肠黏膜屏障保护作用,表现为能降低血浆中D-乳酸含量和DAO活性,减轻肠黏膜损伤,保护肠黏膜屏障.卡巴胆碱联合膳食纤维降低血浆D-乳酸和DAO水平及减轻肠黏膜损伤的效果与单纯卡巴胆碱相当.
