Departamento de Alimentos da Faculdade de Farmácia da Universidade Federal de Minas Gerais, Belo Horizonte, Brasil.
JPEN J Parenter Enteral Nutr. 2013 May-Jun;37(3):392-400. doi: 10.1177/0148607112458325. Epub 2012 Aug 22.
Arginine has been shown to have several immunological and trophic properties in stressful diseases. Its metabolites, nitric oxide (NO) and polyamines, are related to arginine's effects. Thus, the aim of this study was to determine the effects of the NO donor L-arginine and the role of inducible NO synthase (iNOS) on intestinal permeability and bacterial translocation in a model of intestinal obstruction (IO) induced by a simple knot in the terminal ileum.
Male C57BL6/J wild-type (WT) and iNOS knockout (iNOS-/-) mice were randomized into 6 groups: Sham and Sham-/- (standard chow), IO and IO-/- (standard chow +IO), and Arg and Arg-/- (standard chow supplemented with arginine + IO). After 7 days of treatment with standard or supplemented chows, IO was induced and intestinal permeability and bacterial translocation were evaluated. The small intestine and its contents were harvested for histopathological and morphometric analysis and the determination of polyamine concentration.
Pretreatment with arginine maintained intestinal permeability (P > .05; Arg and Arg-/- groups vs Sham and Sham-/- groups), increased polyamine concentration in intestinal content (P < .05; Arg vs IO group), and decreased bacterial translocation in WT animals (Arg group vs IO and IO-/- groups). Absence of iNOS also presented a protective effect on permeability but not on bacterial translocation.
Arginine supplementation and synthesis of NO by iNOS are important factors in decreasing bacterial translocation. However, when intestinal permeability was considered, NO had a detrimental role.
精氨酸在应激性疾病中具有多种免疫和营养特性。其代谢产物一氧化氮（NO）和多胺与精氨酸的作用有关。因此，本研究旨在确定 NO 供体 L-精氨酸的作用及其诱导型一氧化氮合酶（iNOS）在末端回肠简单结扎引起的肠阻塞（IO）模型中对肠道通透性和细菌易位的影响。
雄性 C57BL6/J 野生型（WT）和 iNOS 敲除（iNOS-/-）小鼠随机分为 6 组：假手术和 Sham-/-（标准饲料）、IO 和 IO-/-（标准饲料+IO）以及 Arg 和 Arg-/-（标准饲料补充精氨酸+IO）。在标准或补充饲料治疗 7 天后，诱导 IO 并评估肠道通透性和细菌易位。采集小肠及其内容物进行组织病理学和形态计量学分析以及多胺浓度测定。
精氨酸预处理维持了肠道通透性（P>0.05；Arg 和 Arg-/-组与 Sham 和 Sham-/-组），增加了肠道内容物中的多胺浓度（P<0.05；Arg 组与 IO 组），并减少了 WT 动物的细菌易位（Arg 组与 IO 和 IO-/-组）。iNOS 缺失也对通透性具有保护作用，但对细菌易位没有作用。
精氨酸补充和 iNOS 合成的 NO 是减少细菌易位的重要因素。然而，当考虑肠道通透性时，NO 则具有有害作用。
