饲粮粗蛋白质水平对断奶仔猪肝脏氨基酸代谢酶活性及转运载体mRNA表达的影响

Effects of Dietary Crude Protein Level on Activities of Amino Acid Metabolic Enzymes and mRNA Expression of Amino Acid Transporters in Liver of Weaned Piglets

本试验旨在研究饲粮粗蛋白质(CP)水平对断奶仔猪肝脏氨基酸代谢酶活性及转运载体mRNA表达的影响。选用28日龄、体重[(7.0±0.5)kg]相近、健康的"杜×长×大"杂交断奶仔猪54头(公母各占1/2),随机分为3组[20%CP组(对照组)、17%CP组和14%CP组],每组18个重复,每个重复1头猪。预试期7 d,正试期45 d。正试期的第10、25和45天,分别从每组挑选6头仔猪进行屠宰。结果表明:1)试验第10天时,14%和17%CP组断奶仔猪的肝脏谷草转氨酶(GOT)活性显著低于对照组(P<0.05);14%CP组的肝脏谷氨酰胺合成酶(GS)活性显著低于其他2组(P<0.05)。第25天时,14%CP组的肝脏GOT和GS活性显著低于对照组(P<0.05);14%和17%CP组的肝脏谷丙转氨酶(GPT)和谷氨酸脱氢酶(GDH)活性显著低于对照组(P<0.05)。第45天时,14%CP组的肝脏GPT和GS活性显著低于其他2组(P<0.05)。2)试验第25天时,14%CP组断奶仔猪的肝脏可溶性载体6家族成员15(SLC6A15)和可溶性载体38家族成员2(SLC38A2)的mRNA相对表达量显著低于对照组(P<0.05);14%和17%CP组的肝脏可溶性载体36家族成员1(SLC36A1)的mRNA相对表达量显著低于对照组(P<0.05)。第45天时,14%和17%CP组的肝脏可溶性载体6家族成员20(SLC6A20)和SLC38A2的mRNA相对表达量显著低于对照组(P<0.05);14%CP组的肝脏SLC6A15的mRNA相对表达量显著低于其他2组(P<0.05)。由此可见,饲粮CP水平降低3%和6%可以降低断奶仔猪肝脏氨基酸代谢酶的活性及转运载体mRNA的相对表达量。

The aim of this study was to determine the effects of dietary crude protein(CP)level on activities of amino acid metabolic enzymes and mRNA expression of amino acid transporters in liver of weaned piglets.Fifty-four 28-days-old healthy“Duroc×Landrace×Yorkshire”hybrid weaned piglets(males and females in half)with the similar body weight[(7.0±0.5)kg]were randomly allotted to 3 groups[20.0%CP group(control group),17.0%CP group and 14.0%CP group],and 18 replicates per group and 1 pig per replicate.The pre-trial lasted for 7 days,and the trial lasted for 45 days.Six piglets were selected from each group and slaughtered at the 10 th day,the 25 th day and the 45 th day,respectively.The results showed as follows:1)at the 10 th day,the activity of glutamic-oxaloacetic transaminase(GOT)in liver of weaned piglets in groups 14%and 17%CP was significantly lower than that in control group(P<0.05),and the activity of glutamine synthetase(GS)in liver in group 14%CP was significantly lower than that in the other 2 group(P<0.05).At the 25 th day,the activities of GOT and GS in liver in group 14%CP were significantly lower than those in control group(P<0.05),and the activities of glutamic-pyruvic transaminase(GPT)and glutamic acid dehydrogenase(GDH)in liver in groups 14%and 17%CP were significantly lower than those in control group(P<0.05).At the 45 th day,the activities of GPT and GS in liver in group 14%CP were significantly lower than those in the other 2 groups(P<0.05).2)At 25 th day,the mRNA relative expressions of solute carrier family 6 member 15(SLC6A15)and solute carrier family 38 member 2(SLC38A2)in liver of weaned piglets in group 14%CP were significantly lower than those in control group(P<0.05),and the mRNA relative expression of solute carrier family 36 member 1(SLC36A1)in liver in groups 14%and 17%CP was significantly lower than that in control group(P<0.05).At 45 th day,the mRNA relative expressions of solute carrier family 6 member 20(SLC6A20)and SLC38A2 in liver in groups 14%and 17%CP were significantly lower than those in control group(P<0.05),and the mRNA relative expression of SLC6A15 in liver in group 14%CP was significantly lower than that in the other 2 group(P<0.05).In conclusion,reducing dietary CP level by 3%and 6%can reduce the activities of amino acid metabolic enzymes and the mRNA relative expressions of amino acid transporters in liver of weaned piglets.