N-乙酰半胱氨酸对脂多糖刺激仔猪小肠黏膜免疫应激的影响

Effects of N-acetylcysteine on Intestinal Mucosal Immunological Stress in Piglets Chronically Challenged with Lipopolysaccharide

研究N-乙酰半胱氨酸(NAC)对脂多糖(LPS)刺激仔猪免疫应激的影响。选取18头健康仔猪,随机分成3个处理(对照组、LPS组和NAC组),每个处理6个重复。对照组和LPS组饲喂基础日粮,NAC组饲喂基础日粮+500 mg/kgNAC。试验期为20 d。LPS组和NAC组于试验第10、13、20天腹膜注射100μg/kg BW的LPS,对照组注射相应剂量的灭菌生理盐水。第10、20天注射LPS后3 h采血,第21天屠宰,取小肠黏膜。结果表明:NAC缓解了LPS刺激导致的血浆和小肠黏膜中TNF-α、IL-6、PGE2含量的升高(P<0.05),缓解了小肠黏膜HSP70相对表达量的升高(P<0.05)。由此可见,日粮中添加500 mg/kg NAC可有效抑制LPS刺激导致的血浆及小肠黏膜中炎性因子的升高,缓解免疫应激。

The aim of the current study was to evaluate effects of dietary supplementation with N-acetylcysteine（NAC）on intestinal mucosal immunological stress with reference to its molecular mechanism in piglets after lipopolysaccharide（LPS） challenge.Eighteen healthy piglets with the same genetic origin（Duroc ×Landrace × Large white） and similar body weight（11.58 ± 0.26 kg BW） were randomly allocated to 3 treatments（control group,LPS group and NAC group）.Each treatment included 6 replicates,one piglet per replicate.The piglets in the control group and LPS group were fed with the basal diet,while the NAC group was fed with the basal diet ＋ 500 mg/kg NAC.The feeding period was 20 days.On 10,13 and 20 d,the piglets in the LPS and NAC groups were injected intraperitoneally with 100 μg/kg BW LPS,and the piglets in the control group were injected intraperitoneally with the same dose of physiological saline.On 10 and 20 d,blood samples were collected from precava vein after 3 h post-injection of LPS.On 21 d,all the piglets were sacrificed to collect jejunal and ileal mucosa for analysis.The results showed that dietary supplementation of NAC significantly attenuated the increase of TNF-α,IL-6 and PGE2 in plasma and,jejunal,ileal mucosa,the increase of TNF-α and COR in duodenal mucosa,induced by LPS challenge（P0.05）,attenuated the increase of the expression of HSP70 induced by LPS challenge（P0.05）,trended to attenuate the increase of IL-6 in in duodenal mucosa（P0.1）.Under the present experimental conditions,dietary supplementation with 500 mg/kg NAC inhibited increases of inflammatory mediums in plasma and intestinal mucosa,alleviated immunological stress.