N-乙酰半胱氨酸对脂多糖刺激仔猪免疫应激和能量状况的影响

Effects of N-acetylcysteine on Immunological Stress and Energy Status of Piglets Chronically Challenged with Lipopolysaccharide

本研究旨在N-乙酰半胱氨酸(NAC)对脂多糖(LPS)刺激仔猪肝脏免疫应激和能量状况的影响及其机理进行探讨。选取18头健康仔猪(杜洛克×长白×大白,体质量(11.58±0.26)kg),随机分成3个处理(对照组、LPS组和NAC组),每个处理6个重复,每个重复1头猪。对照组和LPS组饲喂基础日粮,NAC组饲喂基础日粮+500mg.kg-1 NAC,LPS和NAC组仔猪分别于试验的第10、13、20天腹膜注射100μg.kg-1 BW的LPS,对照组注射等量的灭菌生理盐水。第10、20天注射LPS后3h前腔静脉采血,第21天仔猪麻醉后进行屠宰,取肝脏样品待测。试验结果显示:(1)日粮中添加NAC显著缓解了LPS刺激导致的ADG降低(P<0.05)和F/G的升高(P<0.05)。(2)日粮中添加NAC缓解了LPS刺激导致的血浆、肝脏中TNF-α、IL-6和PGE2的升高(P<0.05)。(3)日粮中添加NAC缓解了LPS刺激导致的肝脏核因子-κB(NF-κB)和热休克蛋白70(HSP70)蛋白表达量的升高(P<0.05)。(4)日粮中添加NAC缓解了LPS刺激导致的肝脏中三磷酸腺苷(ATP)、二磷酸腺苷(ADP)和能荷(EC)水平的降低(P<0.05)及一磷酸腺苷(AMP)水平和AMP/ATP比值的升高(P<0.05)。由此可见,日粮中添加500mg.kg-1 NAC可能通过缓解LPS导致的免疫应激和能量的过度损耗,促进仔猪生长。

The aim of the current study was to evaluate the effects of dietary supplementation with N-acetylcysteine（NAC）on liver immunological stress and energy status in piglets after lipopolysaccharide（LPS） challenge.Eighteen healthy piglets with the same genetic origin and similar body weight（Duroc ×Landrace × Large white,（11.58 ± 0.26） kg BW） were randomly allocated into 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^-1 NAC.On d10,d13 and d20,the piglets in the LPS and NAC groups were injected intraperitoneally with 100 μg·kg-1 BW LPS,and the piglets in the control group were injected intraperitoneally with the same dose of physiological saline.On d10 and d20,blood samples were collected from precava vein after 3 h post-injection of LPS.On d21,all the piglets were sacrificed to collect liver for analysis.The results showed that：（1） Dietary supplementation of NAC attenuated the decrease of F/G（P〈0.05）and the increase of ADG（P〈0.05）.（2） Dietary supplementation of NAC significantly attenuated the increase of TNF-α,IL-6 and PGE2 in plasma and liver（P〈0.05）.（3） Dietary supplementation of NAC attenuated the increase of the expression of NF-κB and HSP70 induced by LPS challenge（P〈0.05）.（4） Dietary supplementation of NAC attenuated the decrease of ATP,ADP and energy charge（EC）,while attenuated the increase of AMP level and AMP/ATP induced by LPS challenge significantly（P〈0.05）.These results indicated,under the present experimental conditions,dietary supplementation with 500 mg·kg-1 NAC could significantly improve growth performance via ameliorating the immunological stress and energy depletion in piglets challenged with LPS.