运输前灌服谷氨酰胺对运输应激雏鸡肠黏膜上皮细胞线粒体功能及坏死性凋亡信号通路的影响

Effects of Glutamine Oral Administration before Transportation on Mitochondrial Function and Necrotic Apoptosis Signal Pathway of Intestinal Mucosal Epithelial Cells of Chicks under Transportation Stress

本试验旨在研究运输前灌服谷氨酰胺(Gln)对运输应激雏鸡肠黏膜上皮细胞线粒体功能及坏死性凋亡信号通路的影响。试验选取体重相近且健康的1日龄爱拔益佳(AA)肉鸡300羽,随机分为5个组(A、B、C、D和E组),每组5个重复,每个重复12羽。A、B组运输前灌服1 mL生理盐水,C、D和E组运输前分别灌服1 mL质量分数为0.50、0.75和1.00 g/kg的Gln。灌服均在雏鸡出壳后1 h内完成,灌服结束后A组不做运输应激处理,B、C、D和E组以70 km/h的速度运输应激5 h。结果表明:1)与A组相比,B、C、D和E组空肠线粒体跨膜电位及烟酰胺腺嘌呤二核苷酸(NAD+)、ATP含量显著降低(P<0.05),线粒体还原型烟酰胺腺嘌呤二核苷酸(NADH)含量显著增加(P<0.05)。与B组相比,C、D和E组空肠线粒体跨膜电位、ATP含量显著增加(P<0.05),线粒体NADH含量显著降低(P<0.05);D和E组线粒体NAD+含量显著增加(P<0.05)。2)与A组相比,B、C、D和E组空肠黏膜受体相互作用蛋白激酶1(RIPK1)、受体相互作用蛋白激酶3(RIPK3)和混合谱系激酶结构域样假激酶(MLKL)mRNA和蛋白表达水平显著增加(P<0.05)。与B组相比,C、D和E组空肠黏膜RIPK1、RIPK3和MLKL mRNA和蛋白表达水平显著降低(P<0.05)。综上所述,5 h的运输应激导致雏鸡空肠线粒体损伤,加快肠黏膜细胞凋亡进程,而运输前灌服Gln可有效缓解由运输应激造成的上述不利影响,且以灌服剂量为0.75 g/kg时效果较好。

The purpose of this experiment was to investigate the effects of glutamine(Gln)oral administration before transportation on mitochondrial function and necrotic apoptosis signal pathway of intestinal mucosal epithelial cells of chicks under transportation stress.Three hundred 1-day-old Arbor Acres(AA)broilers with similar body weight were randomly divided into 5 groups(groups A,B,C,D and E)with 5 replicates per group and 12 broilers per replicate.Broilers in groups A and B were orally administered with 1 mL normal saline before transportation,and broilers in groups C,D and E were orally administered 1 mL Glu with mass fractions of 0.05,0.75 and 1.00 g/kg before transportation,respectively.Oral administration was completed within one hour after the chicks were hatched.Broilers in group A were treated with no transportation stress,and boilers in groups B,C,D and E were treated with 5 h transportation stress with a speed of 70 km/h.The results showed as follows:1)compared with group A,the mitochondrial transmembrane potential and contents of nicotinamide adenine dinucleotide(NAD+)and ATP in jejunum of groups B,C,D and E were significantly decreased(P<0.05),and the mitochondrial reduced nicotinamide adenine dinucleotide(NADH)content was significantly increased(P<0.05).Compared with group B,the mitochondrial transmembrane potential and ATP content of in jejunum of groups C,D and E were significantly increased(P<0.05),and the mitochondrial NADH content was significantly increased(P<0.05);the mitochondrial NAD+of groups D and E was significantly increased(P<0.05).2)Compared with group A,the mRNA and protein expression levels of receptor interacting serine/threonine protein kinase 1(RIPK1),receptor interacting serine/threonine protein kinase 3(RIPK3)and mixed lineage kinase domain like pseudokinase(MLKL)in jejunal mucosa of groups B,C,D and E were significantly increased(P<0.05).Compared with group B,the mRNA and protein expression levels of RIPK1,RIPK3 and MLKL in jejunal mucosa of groups C,D and E were significantly decreased(P<0.05).In conclusion,the 5 h transportation stress can cause the jejunal mitochondrial damage of chicks,and accelerate the process of apoptosis in intestinal mucosa,while oral administration of Gln before transportation can effectively alleviate these adverse effects caused by transportation stress,and the recommended oral administration dose is 0.75 g/kg.