DIETARY PLANT LECTINS AND THE SMALL INTESTINE

膳食植物凝集素和小肠

• 批准号: 3229859
• 负责人: JOHN G BANWELL
• 金额: $ 13.67万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 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/3229859
• 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

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.

可食用豆类含有几种生长抑制因子，它们会导致 动物肠道吸收不良和体重减轻：哪些不良反应 在无菌状态下和通过抗生素治疗都得到了改善。纯净的 植物血凝素(PHA)与红细胞凝集(E4)和有丝分裂 (L4)从红四季豆中分离出异凝集素 琼脂糖硫球蛋白亲和层析和离子交换层析。受损的 脂肪、氮和维生素B12的吸收，当PHA 合并到饮食中，与肠道细菌有关 过度生长。这些影响可能是由于(A)PHA与 肠道微绒毛膜和(B)随后的粘附性相互作用 在粘膜表面附近有特定的细菌菌群。 利用PHA凝集素诱导的腹泻病体内模型， 粘附性小肠细菌的类型和分布将是 用细菌培养和免疫荧光染色确定，和琼脂 凝胶形态计量学技术分离贴壁微生物。这个 PHA诱导细菌黏附的机制及表面作用 将定义特定粘附菌的成分，以确定 PHA是否识别类似的糖类残留物在粘膜和 细菌表面，并跨越它们之间的桥梁。粘液层的成分 将检查PHA和/或特定细菌粘附性的证据。 将分离肠道微绒毛膜E4和L4受体 利用膜蛋白的增溶和亲和分离 层析法。识别和隔离将利用 Southern和SDS-PAGE的电印迹技术。 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、脂和维生素B12吸收不良与一种 附着的微生物菌群。 粘液层中微生物种群的变化可能是一个因素 在慢性人类肠道疾病中具有重要意义。肠道活组织检查 保留粘液层的组织将通过特别的研究 列举和绘制分布和范围的形态技术 微生物的定殖化。热带主流道的患者将被比较 研究原住民和移民对照受试者在 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模式。