N-乙酰半胱氨酸灌胃对超早期断奶仔猪血浆中游离氨基酸及小肠形态结构与功能的影响

摘要

The study was conducted to investigate the effects of intragastric administration of N-acetylcysteine (NAC) on plasma free amino acid composition and intestinal morphology function of ultral-early weanned pigs.The 22 weight (2.99±0.41) kg of 7-day-old weaned piglets were randomly divided into control group and NAC group.Each group had 11 replicates.The two groups were fed a basal milk,the NAC group were fed NAC with 50 mg/kg body weight per day by intragastric administration,and the control group were fed the same volume of saline per day.On d 11,D-xylose was orally administrated at the dose of 0.1 g/kgB· W and blood samples were collected 1 h after then.All the piglets were sacrificed on d 11 to examine small intestinal morphology and collect intestinal mucosa for analysis.Compared with the control group,the NAC group increased obviously the average daily gain (ADG) (P＜0.05).NAC increased the levels of glutamine,cysteine,and gamma-amino acid (P＜0.05) in the plasma of piglets,and decreased the content of urea nitrogen,cysteine,tryptophan and diamine oxidase (DAO) in the plasma of piglets (P＜0.05).The NAC group increased in the villi height/crypt depth of the duodenal mucosa of piglets (P＜0.05).Additionally,NAC tended to decrease the crypt depth of duodenal mucosa (P＞0.10)and increase the villus width of jejunal mucosa (P＞0.10) and the villi height of ileal mucosa (P＞0.10).In conclusion,under the experimental conditions,dintragastric administration of NAC could improve the morphology and barrier function of small intestine,enhance the utilization of amino acids.%本试验旨在研究N-乙酰半胱氨酸(N-acetylcysteine,NAC)灌胃对超早期断奶仔猪血浆中游离氨基酸、小肠形态结构及功能的影响.将22头体重为(2.99±0.41) kg的7日龄断奶仔猪随机分为对照组和NAC组,每组1 1个重复,每个重复1头猪.在饲喂人工乳的基础上,NAC组每天每头按50 mg/kg体重进行NAC灌胃,对照组每天每头进行同体积的生理盐水灌胃.于试验第11天按0.1 g/kg体重的剂量给仔猪灌服D-木糖溶液,1h后前腔静脉采血,然后屠宰取小肠组织样,刮取肠黏膜及制作组织切片.结果表明:与对照组相比,NAC组显著提高了超早期断奶仔猪平均日增重(P＜0.05);提高了超早期断奶仔猪血浆中谷氨酰胺、胱氨酸、γ-氨基丁酸水平(P＜0.05),降低了血浆中尿素氮、半胱氨酸、色氨酸水平和二胺氧化酶活力(P＜0.05):NAC灌胃提高了哺乳仔猪十二指肠黏膜的绒毛高度/隐窝深度(P＜0.05),有降低十二指肠隐窝深度的趋势(P＜0.10),有提高空肠绒毛宽度和回肠绒毛高度的趋势(P＞0.10).在本试验条件下,NAC灌胃可改善小肠形态结构与屏障功能,提高氨基酸的利用率,调节血浆中部分氨基酸的含量.