日粮添加亮氨酸对宫内发育迟缓断奶仔猪小肠葡萄糖吸收和能量代谢的影响

Effects of leucine supplementation on the small intestinal glucose absolution and energy metabolism in weanling piglets with intrauterine growth retardation

[目的]本文旨在研究亮氨酸对宫内发育迟缓(IUGR)断奶仔猪小肠葡萄糖吸收和能量代谢的影响。[方法]从正常分娩的16头母猪中选择正常初生体质量(NBW)和IUGR新生仔猪各16头,于14日龄断奶,分别饲喂基础日粮(含1.45%亮氨酸)或亮氨酸日粮(含1.80%亮氨酸)并随机分为4组,即NC(NBW+基础日粮)、NL(NBW+亮氨酸日粮)、IC(IUGR+基础日粮)、IL(IUGR+亮氨酸日粮),每组8头,公母各半,35日龄屠宰取样,对空肠酶活性和相关酶mRNA表达量进行测定。[结果]IUGR仔猪空肠AKP、Na^+/K^+-ATP酶、PK和线粒体MDH活性及ATP含量均显著下降(P<0.05),SGLT1和PK mRNA的表达量有下降的趋势,而AMPK-α1和mTOR mRNA的表达量显著下降(P<0.05);日粮添加亮氨酸促使IUGR仔猪空肠AKP及线粒体MDH和SDH活性显著升高(P<0.05),Na^+/K^+-ATP活性和ATP含量有升高的趋势,SGLT1、GLUT2、AMPK-α1和mTOR mRNA的表达量显著升高(P<0.05)。[结论]日粮中添加亮氨酸能够有效提高IUGR仔猪小肠葡萄糖吸收和能量代谢关键酶活性及基因表达量,促进小肠的发育,改善小肠葡萄糖吸收和能量代谢状态。

[Objectives] The paper aims to investigate the effects of leucine on the small intestinal glucose absolution and energy metabolism in weanling piglets with intrauterine growth retardation（IUGR）.[Methods] Sixteen normal birth weight（NBW） piglets and sixteen IUGR piglets were selected according to birth weight.At weaning（14 days of age）,both NBW and IUGR piglets were fed control diet（containing 1.45% leucine）or leucine diet（containing 1.80% leucine）.Then,all piglets were randomly distributed into 4 treatments：NC （NBW＋control diet）,NL （NBW＋leucine diet）,IC （IUGR ＋control diet） and IL （IUGR＋leucine diet） for 21 d （n =8）.Totally 8 piglets were selected from each group and slaughtered,and the jejunal enzyme activities and mRNA expression were measured.[Results] The results showed that the activities of AKP,Na^＋/K^＋-ATPase,PK and the content of ATP in the jejunum,and the activity of MDH in the jejunal mitochondria were markedly decreased in IUGR piglets （P〈 0.05）.A tendency toward decreased SGLT1 and PK mRNA expressions were observed in the jejunum,whilst IUGR significantly decreased AMPK-α1 and mTOR mRNA expressions（P〈0.05）.Consumption of the leucine diet significantly increased the activity of AKP in the jejunum,and the activities of MDH and SDH in the jejunal mitochondria of IUGR piglets（P〈0.05）,but Na^＋/K^＋-ATPase activity and ATP content in the jejunum showed a slight increase after leucine treatment,and there was a significant increase in SGLT1,GLUT2,AMPK-α1 and mTOR mRNA expressions（P〈0.05）.[Conclusions] These results indicate that dietary leucine supplementation could improve the small intestinal development,and ameliorate small intestinal glucose absorption and energy metabolic status,by increasing the key enzyme activities and gene expressions of glucose absorption and energy metabolic effectively.