Dietary L-arginine Supplementation Improves Intestinal Function in Weaned Pigs after an Escherichia coli Lipopolysaccharide Challenge

Yulan Liu,Junjun Wang,Xiaoqiu Wang,Jie Han,Jingjing Huang,Fenglai Wang

doi:10.5713/ajas.2009.90100

Abstract

This study was conducted to determine whether L-arginine (Arg) supplementation could improve intestinal function in weaned pigs after an Escherichia coli lipopolysaccharide (LPS) challenge. Treatments included: i) non-challenged control (CONTR, pigs fed a control diet and injected with sterile saline); ii) LPS-challenged control (LPS, pigs fed the same control diet and challenged by injection with Escherichia coli LPS); iii) LPS+0.5% Arg (pigs fed a 0.5% Arg diet and challenged with LPS); and iv) LPS+1.0% Arg (pigs fed a 1.0% Arg diet and challenged with LPS). On d 16, pigs were administrated with LPS or sterile saline. D-xylose was orally administrated at 2 h following LPS challenge, and blood samples were collected at 3 h following LPS challenge. At 6 h post-challenge, pigs were sacrificed and intestinal mucosa samples were collected. Supplementation of Arg attenuated LPS-induced damage in gut digestive and barrier functions, as indicated by an increase in ileal lactase activity, and duodenal and ileal diamine oxidase activities (p<0.05). Arg administration also prevented the increase of jejunal malondialdehyde content and the decrease of ileal superoxide dismutase activity by LPS challenge (p<0.05). Furthermore, the jejunal nitric oxide level and inducible nitric oxide synthase activity were also improved after Arg supplementation (p<0.05). These results indicate that Arg supplementation has beneficial effects in alleviating the impairment of gut function induced by LPS challenge.

Highlights

In pig production, numerous factors such as weaning, infection and stress can lead to intestinal mucosal disruption (Liu et al, 2008a; Wang et al, 2008a, b), which may result in diarrhea and growth retardation of pigs
Arg supplementation did not affect plasma d-xylose content compared to the LPS pigs (p>0.05)
To explore whether dietary Arg supplementation could mitigate the impairment of intestinal function in weaned pigs, we used a welldocumented model for inducing intestinal injury in weaned pigs by administrating Escherichia coli LPS (Mercer et al, 1996)

Summary

Introduction

Numerous factors such as weaning, infection and stress can lead to intestinal mucosal disruption (Liu et al, 2008a; Wang et al, 2008a, b), which may result in diarrhea and growth retardation of pigs. Nutritional modulation of the injured gut is very important to the compromised pigs. In the last 20 years, Arg has attracted extensive attention because it has been shown to play an important role in various physiological and biological processes (Wu et al, 2004; Wu et al, 2007a, b). Arg is the substrate for the synthesis of nitric oxide (NO), a key mediator of gut physiological function (Wang et al, 2009), immune response (Han et al, 2008) and neurological. Our aim was to investigate whether dietary Arg supplementation could mitigate the impairment of intestinal function and to examine the mechanism(s) of action of Arg in weaned pigs

Objectives

Methods

Results

Conclusion