赖氨酸铜对仔猪血清IGF-I、肝细胞膜GHR水平及肝脏、肌肉基因表达的影响

Effect of Cu-Lys on the Levels of Liver GHR and Serum IGF-I and the Gene Expression of GHR and IGF-I in Liver and Semitendinosus of Post-Weaning Pigs

为研究赖氨酸铜对仔猪生长的影响及其机理,选用21日龄断奶仔猪220头,均分为5组.A、B、C、D、E组分别在基础日粮(含铜15 mg/kg)中添加0、50、100、200 mg/kg赖氨酸铜来源的铜和200 mg/kg硫酸铜来源的铜.42、63日龄时称仔猪个体质量,并于63日龄每组屠宰4头,测定血清IGF-I、肝细胞膜GHR水平及肝脏、肌肉GHR mR-NA、IGF-I mRNA含量.结果显示B、C、D、E组全期日增质量分别比A组提高8%、13.8%(P<0.05)、16.7%(P<0.05)、14.1%(P<0.05);日粮中添加铜可显著提高血清IGF-I浓度、肝脏GHR mRNA水平(P<0.05)及肝细胞膜GHR特异结合活性(P<0.05),肝脏IGF-I mRNA水平有上升趋势但差异不显著(P>0.05).结果提示:较低剂量赖氨酸铜来源的铜(100 mg/kg)可起到较高剂量硫酸铜来源的铜(200 mg/kg)的促生长作用;赖氨酸铜促进仔猪生长可能与其上调肝脏GHR、IGF-I的基因表达,提高生长轴GHR及血液中IGF-I水平有关.

The objectives of the present study were to investigate the effect and mechanisms of Cu-Lys on pig performance.220 pigs weaned at 21 d of age were divided into 5 treatments.Pigs in treatments A,B,C,D,E were fed with basal diets（15 mg/kg of Cu） supplemented with 0,50,100,200 mg/kg of Cu from Cu-Lys and 200 mg/kg of Cu from copper sulfate.Pigs were weighted individually on days 42 and 63,respectively.Four pigs per treatment were killed to collect the samples of liver,ST for quantification of GHR mRNA and IGF-I mRNA.Results showed that compared with treatment A,the ADG increased 8%,13.8%（P〈0.05）,16.7%（P〈0.05）and 14.1%（P〈0.05）,respectively in treatments B,C,D,E.Supplement with Cu increased the GHR（P〈0.05）,the expression of GHR mRNA in liver（P〈0.05）,and serum IGF-I（P〈0.05）,but the expression of GHR mRNA was not significant（P〉0.05）.The results indicate that lower doses of Cu from Cu-Lys caused the same effect as higher doses of Cu from CuSO4;One of the possible mechanisms on copper improving pig performance is that Cu stimulates the gene expression of GHR,improves the GHR in liver and serum IGF-I.