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DIETARY PLANT LECTINS AND THE SMALL INTESTINE

膳食植物凝集素和小肠

基本信息

批准号：
3152199
负责人：
JOHN G BANWELL
金额：
$ 14.92万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
1981
资助国家：
美国
起止时间：
1981-07-01 至 1987-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/3152199
关键词：
Leguminoseae affinity chromatography diarrhea electrophoresis enteric bacteria human tissue intestines malabsorption malnutrition membrane activity microorganism population study nutrition related tag radiotracer tropical sprue

项目摘要

Edible legumes contain several growth inhibitory factors which cause intestinal malabsorption and weight loss in animals: adverse effects which are ameliorated in the germ free state and by antibiotic therapy. Purified phytohemagglutinin (PHA) and the erythroagglutinating (E4) and mitogenic (L4) isolectins have been isolated from red kidney beans by sepharosethyroglobulin affinity and ion exchange chromatography. Impaired lipid, nitrogen and vitamin B12 absorption which develop when PHA is incorporated in the diet, is associated with intestinal bacterial overgrowth. The effects may result from (a) binding of the PHA to the intestinal microvillus membrane and (b) subsequent adhesive interaction with a specific bacterial flora adjacent to the mucosal surface. Utilizing this in vivo model of PHA lectin induced diarrheal disease, the types and distribution of adherent small intestinal bacteria will be defined using bacterial culture and immunofluorescent staining, and an agar gel morphometric technique to isolate adherent microorganisms. The mechanism of the PHA-induced bacterial adherence and role of surface components of specific adherent bacteria will be defined to determine whether PHA recognizes similar saccharrides residues at the mucosal and bacterial surfaces and cross bridges them. Components of the mucus layer will be examined for evidence of PHA and/or specific bacterial adherence. Intestinal microvillus membrane receptors for E4 and L4 will be isolated using solubilization of membrane proteins and separation by affinity chromatography. Identification and isolation will utilize the electroblotting technique of Southern and SDS-PAGE electrophoresis. Purified soy lectin will be studied in a manner similar to PHA to detect malabsorption of nitrogen, lipid and vitamin B12 in association with an adherent microbial flora. Changes in populations of microorganisms in the mucus layer may be a factor of importance in chronic human intestinal disorders. Intestinal biopsy tissue on which the mucus layer is retained will be studied by special morphological techniques to enumerate and map the distribution and extent of microbial colonization. Patients with tropical sprue will be compared to indigenous and emigrant control subjects to study differences in the mucus layer. Tissue of patients will be examined before and after antibiotic administration and other modes of therapy.

食用豆类含有几种生长抑制因子，动物肠道吸收不良和体重减轻：在无菌状态下和通过抗生素治疗得到改善。纯化植物血凝素（PHA）和红细胞凝集素（E4）和促有丝分裂素 (L4)已通过以下方法从红芸豆中分离出异凝集素：琼脂糖甲状腺球蛋白亲和层析和离子交换层析。受损脂质、氮和维生素B12的吸收，当PHA 在饮食中，与肠道细菌有关，过度生长这些作用可能是由于（a）PHA与PHA的结合，肠微绒毛膜和（B）随后粘附相互作用具有邻近粘膜表面的特定细菌植物群。利用这种PHA凝集素诱导的结肠炎疾病的体内模型，粘附的小肠细菌的类型和分布将使用细菌培养和免疫荧光染色确定，以及琼脂凝胶形态测定技术分离粘附的微生物。的 PHA诱导细菌粘附的机制及表面的作用将定义特定粘附细菌的组分，以确定 PHA是否识别粘膜上类似的糖类残留物，细菌的表面，并跨越桥梁。粘液层的成分将检查PHA和/或特定细菌粘附的证据。将分离E4和L4的肠微绒毛膜受体利用膜蛋白的溶解和亲和分离层析识别和隔离将利用 Southern电印迹技术和SDS-PAGE电泳。纯化的大豆凝集素将以类似于PHA的方式进行研究，以检测氮、脂质和维生素B12的吸收不良，附着的微生物植物群。粘液层中微生物数量的变化可能是一个因素在慢性人类肠道疾病中的重要性。肠活检保留粘液层的组织将通过特殊的形态学技术来列举和绘制分布和范围微生物的殖民。热带口炎性腹泻患者将被比较土著和移民对照组研究差异，粘液层患者的组织将在手术前后进行检查抗生素给药和其他治疗方式。