肠粘膜中氨基酸的分解代谢及其意义

近年来研究发现饲粮中氨基酸在通过小肠粘膜吸收时大量地分解代谢，肠粘膜中氨基酸的分解代谢是维持肠粘膜完整性和正常功能所必需，对饲粮中蛋白质、氨基酸在人和动物体同的利用也有重要影响。本综述了近年来这一领域的研究进展。     

断奶日龄对仔猪肠粘膜形态的影响

本文研究了不同断奶日龄对仔猪肠粘膜形态的影响。试验分17日龄（1组）、21日龄（2组）、28日龄（3组）、35日龄（4组）断奶4个处理组，每个处理3个重复，每个重复1窝，定时定点制杀取十二指肠、空肠上段、空肠下段、回肠作组织切片，观察其绒毛高度、隐窝 深度、绒毛宽度、肠壁厚度。结果表明，仔猪十二指肠、空肠上段、空肠下段和回肠的绒毛高度、隐窝深度、绒毛宽度、肠壁厚度均有不同程度的变化；断奶日龄越早，仔猪肠粘膜变化越大，其中绒毛高度下降幅度越大，恢复时间越长，一般在断奶后8－12d降至最低，随后恢复较快。1组仔猪十二指肠、空肠上段、回肠隐窝深度显著下降；绒毛宽度各组各部位均呈先变窄后变宽趋势，肠壁厚度以1组变化明显。从小肠各部位比较，绒毛高度十二指肠最高，空肠上段次之；隐窝深度、绒毛宽度也以十二指肠最深或最宽；肠壁厚度以回肠最厚。仔猪在29日龄时各组各部位肠粘膜指标降至最低水平，之后，随着日龄的增加，各指标增加显著。     

溶菌酶对肉鸡肠粘膜形态、微生物数量及血氨浓度的影响

试验旨在探讨溶菌酶对肉鸡肠道粘膜形态、微生物数量及血氨浓度的影响,采用单因素试验设计,选择144只艾维茵肉鸡随机分为4组:对照组、抗生素组及2个剂量溶菌酶组(每千克日粮分别添加溶菌酶150、300g),每组6个重复,每个重复6只。考察不同处理组肉鸡肠道形态、微生物数量及血氨浓度,试验结果表明:溶菌酶可改善42日龄肉鸡十二指肠及空肠粘膜形态,降低有害微生物(梭菌和大肠菌类)数量,对双歧杆菌和乳酸菌无显著影响(P>0.05),可极显著降低血氨浓度(P<0.01)。     

肠粘膜免疫与元素硒关系的研究

实验选用24只1日龄健康xx鸡为动物模型,随机分成3组,每组8只,分别饲喂添加含有不同剂量的硒日粮45天后,观察日粮中不同硒水平互作下鸡肠黏膜结构及黏膜免疫相关细胞的形态、结构、数量和分布的变化,并探讨日粮中不同硒对鸡肠道消化吸收和免疫屏障功能的影响。本实验采用硒的3水平试验设计,各实验组日粮中硒含量分别0.08 mg/kg、0.15 mg/kg、5mg/kg。实验表明:饲料中加入常硒(0.15mg/kg)是维护正常的鸡肠道消化吸收和屏障功能的最佳剂量,而饲料中硒缺乏或过高时,对鸡肠道消化吸收和屏障功能有不同程度的损伤作用,低硒和高硒可加强其毒害作用,使肠道消化吸收和黏膜屏障功能的损伤加重。     

纳米载铜蒙脱石对断奶仔猪腹泻、肠道菌群及肠粘膜形态的影响

选用96头健康“杜长大“三元杂交断奶仔猪,随机分为3组,每组8头,设4个重复,分别饲喂基础日粮(对照组)、基础日粮 2.0g/kg纳米蒙脱石(MMT)、基础日粮 2.0g/kg纳米载铜蒙脱石(MMT-Cu),研究了MMT-Cu对断奶仔猪腹泻、肠道菌群及其肠粘膜形态的影响.结果表明,与对照组相比,饲料中添加2.0g/kg MMT-cu,能显著(P＜0.05)提高断奶仔猪的平均日增重和饲料转化效率,显著降低腹泻率(P＜0.05);显著降低(P＜0.05)小肠和结肠内容物中大肠杆菌和沙门氏菌的数量;显著提高(P＜0.05)小肠绒毛高度和绒毛高度与隐窝深度的比值;显著提高(P＜0.05)十二指肠微绒毛高度.与对照组相比,添加2.0g/kg MMT也能显著降低断奶仔猪腹泻率(P＜0.05),提高(P＜0.05)小肠绒毛高度和绒毛高度与隐窝深度的比值,但对于断奶仔猪的生长性能和肠道菌群无显著影响(P＞0.05).与添加2.0g/kg MMT相比,添加2.0g/kg MMT-Cu能显著降低(P＜0.05)小肠和结肠内容物中大肠杆菌和沙门氏菌的数量.     

一种新型肠粘膜保护剂——载铜蒙脱石对肠粘膜屏障功能影响的研究

以蒙脱石（MMT）为原料，通过阳离子交换反应合成载铜蒙脱石（MMT-Cu）。为探讨载铜蒙脱石对肠粘膜屏障功能的影响，采用体外培养的单层Caco-2细胞模型为研究对象，以细菌易位数量和肠绒毛损伤程度做为指标进行研究。结果表明：MMT-Cu可明显减少（P〈0．01）E．coilK88、S．choleraesuis侵入到Caco-2细胞内的数量，与对照组相比，下降了2logCFU／mL～3log CFU／mL；并能显著降低（P〈0．01）LDH的释放量。扫描电子显微镜下观察可见，加入MMT-Cu一段时间后，当E．coil K88和S．choleraesuis粘附Caco-2细胞时，微绒毛依旧排列整齐、致密，可见肠上皮细胞保持完好。结果表明，MMT-Cu对肠粘膜具有屏障作用，可作为一种消化道粘膜保护剂。     

外源性谷氨酰胺和谷氨酸对早期断奶仔猪肠粘膜形态、结构和小肠吸收功能及骨骼肌中DNA、RNA浓度的影响

74头28日龄健康二元杂交断奶仔猪分成3组，用于研究外源性谷氨酰胺（glutamine,Gln)和谷氨酰（glutamate, Glu)对断奶仔猪小肠粘膜形态，结构和功能及骨骼肌中DNA，RNA合成的影响。结果表明：与对照组相比，添加1%谷氨酰胺或1%谷氨酸可防止断奶后1周内空肠绒毛萎缩，减少断奶后2周内空肠固有膜内未成熟细胞数；显著改善断奶后1周内小肠吸收功能，并促进肌肉中RNA合成。这些结果为利用Gln、Glu缓解仔猪断奶应激，改善生产性能提供了实验基础。     

异麦芽低聚糖对断奶仔猪肠道VFA浓度、pH值及粘膜形态结构的影响

选择28日龄断奶仔猪54头 ,随机分为9组 ,分别饲喂3种不同日粮处理 ,每种日粮处理组为3个重复。3种日粮分别为添加0.05 %异麦芽低聚糖组(IMO组)、添加110mg/kg阿散酸组(抗生素组)和对照组。各组基础日粮相同。分别于35和42日龄从各重复中选1头屠宰 ,测定盲肠、结肠内容物中挥发性脂肪酸(VFA)浓度、pH值及盲肠、结肠粘膜上皮绒毛高度和隐窝深度。结果表明 ,35日龄时 ,IMO组盲肠乙酸、丙酸 ,结肠乙酸、丙酸及总VFA浓度均显著高于对照组(P<0.05) ;42日龄时 ,IMO组盲肠乙酸、丁酸及总VFA浓度 ,结肠乙酸浓度均显著或极显著(P<0.01)高于对照组 ;结肠绒毛高度受处理影响显著 ,在两次测定中 ,IMO组结肠绒毛高度均显著大于(P<0.05)对照组。35日龄时 ,抗生素组结肠绒毛高度也显著高于对照组(P<0.05)。     

粘膜二糖酶的研究进展

综述二糖酶在动物体内的种类、结构、性质、分泌、分布、发育规律和在消化吸收中的功能，以及影响二糖酶水平的因素，如激素、日粮等，揭示了二糖酶在消化中的重要意义，且论述了二糖酶测定方法的原理。     

The relationship between intestinal and oral mucosa microcirculation in anaesthetized horses

Objective

To compare alteration in intestinal blood flow in anaesthetized horses with changes in oral mucosa blood flow.

鲤鱼肠道中小肽与血液中肽的关系研究

为了研究鲤鱼肠道完整吸收小肽与肠道中小肽的关系,用6．25％酶解酪蛋白、酸解酪蛋白、酪蛋白溶液和生理盐水对鲤鱼进行肠道灌注试验(1ml／100g体重),20min后尾静脉采血制备血浆,用高效液相色谱仪分析。结果表明,鲤鱼血浆中肽量的增加与肠道提供的肽种类和数量有关,鲤鱼肠道能够完整地吸收某些小肽进入血液循环。     

动物胃肠道菌群与其免疫功能和健康的关系

本文主要论述了动物胃肠道微生物和对黏膜免疫、体液免疫和细胞免疫的作用和特点，以及对动物健康状况的影响。     

The quantitative assessment of normal canine small intestinal mucosa.

Quanitative methods of assessing the architecture of small intestinal mucosa have been applied to biopsy material from normal dogs. Mucosal samples taken from four predetermined sites show that there are significant quantitative differences between the various levels of the small bowel. Animals of one year of age and older show no correlation between age or weight and mucosal dimensions. The significance of these findings, in relation to examination of biopsy material from cases of clinical small intestinal disease, is discussed.     

微生态制剂与肠粘膜免疫关系的研究进展

微生态制剂即一类以活菌为主的新型饲料添加剂,无毒、无害、无残留,是目前理想的抗生素替代品,在增强动物免疫力上作用很大。其活菌能在动物肠道内定植,维护肠道菌群平衡,并刺激肠粘膜免疫系统,引起体液免疫和细胞免疫应答,从而增强机体抗病力。     

The quantitative assessment of mucosa in canine small intestinal malabsorption.

Histological sections from the small intestines of dogs showing clinical signs of small intestinal malabsorption have been examined using morphometric techniques. Weibel graticule measurements appear to be a useful adjunct to the subjective assessment of villus atrophy. Severe clinical signs of small intestinal malabsorption may be associated with a patchy distribution of lesions throughout the small bowel.     

Anatomical relationship between enkephalin-containing neurones and caecum-projecting neurones in the chicken intestinal nerve

The anatomical relationship between enkephalin-immunoreactive neurones and caecum-projecting neurones in the intestinal nerve of Remak (INR) of the chicken was investigated using retrograde transport of cholera toxin subunit B and immunohistochemistry with anti-enkephalin serum. After injection of cholera toxin into the base or body of the caecum, labelled neurones were mainly observed in the cranial part of the rectal INR. Enkephalin-immunoreactive neuronal cell bodies were found in the caudal part of the rectal INR and their fibres closely surrounded caecum-projecting neurones in the cranial part of the rectal INR. Diameters of caecum-projecting neurones surrounded with enkephalin-containing terminals were significantly larger than those of caecum- projecting neurones without enkephalin-terminals (P < 0.01). From these results, it is suggested that enkephalin-containing neurones are able to affect large-sized caecum-projecting neurones. This pathway may be involved with unique motility of the rectum and caeca that uric acid is retrogradely carried from the cloaca to the caeca.     

球虫病与维生素的关系

鸡球虫病是由艾美尔科、艾美尔属的各种球虫寄生于鸡肠道上皮细胞所引起的以肠炎、消瘦、贫血、生产性能降低和下痢带血为主要症状的寄生虫病.危害我国养禽业发展的主要是柔嫩、毒害、巨型、堆型和布氏艾美尔球虫.笔者现结合实践经验,论述一下球虫病与维生素的关系,仅供参考.     

Effects of carprofen on the integrity and barrier function of canine colonic mucosa

OBJECTIVE: To measure effects of carprofen on conductance and permeability to mannitol and histologic appearance in canine colonic mucosa. SAMPLE POPULATION: Colonic mucosa from 13 mature mixed-breed dogs. Procedures-Sections of mucosa from the transverse colon and proximal and distal portions of the descending colon were obtained immediately after dogs were euthanized. Sections were mounted in Ussing chambers. Carprofen (400 microg/mL) was added to the bathing solution for treated sections. Conductance was calculated at 15-minute intervals for 240 minutes. Flux of mannitol was calculated for three 1-hour periods. Histologic examination of sections was performed after experiments concluded. Conductance was graphed against time for each chamber, and area under each curve was calculated. Conductance X time, flux of mannitol, and frequency distribution of histologic findings were analyzed for an effect of region and carprofen. RESULTS: Carprofen significantly increased mean conductance X time, compared with values for control (untreated) sections for all regions of colon. Carprofen significantly increased mean flux of mannitol from period 1 to period 2 and from period 2 to period 3 for all regions of colon. Carprofen caused a significant proportion of sections to have severe sloughing of cells and erosions involving >or= 10% of the epithelium, compared with control sections. CONCLUSIONS AND CLINICAL RELEVANCE: Carprofen increased in vitro conductance and permeability to mannitol in canine colonic mucosa. Carprofen resulted in sloughing of cells and erosion of the colonic mucosa. These findings suggested that carprofen can compromise the integrity and barrier function of the colonic mucosa of dogs.