摘要
为研究杜仲叶对绵羊脂肪代谢和肉品质的影响,本研究随机选择70~80日龄、体重25~30 kg的绵羊(湖羊)30只,平均分为3组,分别为对照组(CTL组,饲粮中不含杜仲叶)、低水平杜仲叶组(EUL1组,饲粮含10%杜仲叶)和高水平杜仲叶组(EUL2组,饲粮含20%杜仲叶),每组10只。预试期15 d,正试期90 d。采集血液,测定血浆脂质代谢分析指标;采集背最长肌,测定营养物质含量;采集肝脏组织,测定脂肪代谢相关酶和核转录因子的mRNA表达水平和蛋白水平。结果表明:1)各组干物质采食量EUL1组>EUL2组>CTL组,组间差异显著(P<0.05)。2)与CTL组相比,EUL2组血浆极低密度脂蛋白(VLDL)、高密度脂蛋白(HDL)、非酯化脂肪酸(NEFA)含量显著升高(P<0.05),EUL1和EUL2组血浆低密度脂蛋白(LDL)(0.05≤P<0.10)、总胆固醇(TC)(P<0.05)含量降低。3)与CTL组相比,EUL1组肌肉粗蛋白质含量、EUL2组肌肉粗脂肪含量显著升高(P<0.05),EUL1组肌肉剪切力显著减小(P<0.05)。4)与CTL组相比,EUL1组和EUL2组肌肉饱和脂肪酸(SFA)含量略有降低(P>0.05),肌肉不饱和脂肪酸(UFA)含量显著升高(P<0.05),其中,EUL2组肌肉MUFA、PUFA含量及UFA/SFA显著升高(P<0.05)。5)与CTL组相比,杜仲叶能够显著下调肝脏脂肪合成相关酶硬脂酰辅酶A去饱和酶1(SCD1)和核转录因子固醇调节元件结合蛋白1c(SREBP-1c)、过氧化物酶体增生激活受体γ(PPARγ)的mRNA表达水平(P<0.05);显著上调肝脏脂肪酸分解相关酶肉毒碱棕榈酰基转移酶1A(CPT1A)、脂蛋白酯酶(LPL)mRNA表达水平显著上调(P<0.05);与CTL组相比,EUL2组肝脏SCD1蛋白水平显著下降(P<0.05)。结果提示,杜仲叶通过调节脂肪合成和分解相关基因的表达,显著影响绵羊脂肪的代谢和肌肉脂肪酸的组成。
In order to research the effects of Eucommia ulmoides leaves( EUL) on sheep lipid metabolism and the mechanism,thirty healthy Hu sheep w ith the similar age( 70 to 80 days of age) and body w eight( 25 to30 kg) w ere randomly divided into three groups w ith 10 sheep per group,w hich w ere control group( CTL group,diets w ithout EUL),low level of EUL group( EUL1 group,diet containing 10% EUL),and high level of EUL group( EUL2 group,diets containing 20% EUL). The pre-experimental period lasted for 15 d,the formal experiment period lasted for 90 d. Blood w as collected to determine plasma lipid metabolism indexes;longissimus dorsi muscle w as collected to determine nutrient contents; liver tissue w as collected to determine mRNA expression levels and protein levels of enzymes or nuclear factors involved in lipid metabolism. The results show ed as follow s: 1) dry matter intake show ed EUL1 grou P>EUL2 grou P>CTL group w ith significant difference among groups( P< 0.05). 2) Compared w ith CTL group,plasma contents of total cholesterol( TC)( P<0.05),low-density lipoprotein( LDL)( 0.05≤P<0.10) were reduced,while plasma contents of very low-density lipoprotein( VLDL)( P< 0.05),high-density lipoprotein( HDL),non-esterified fatty acid( NEFA) in EUL2 group w ere significantly increased( P < 0. 05). 3) Compared w ith CTL group,crude protein content of muscle in EUL1 group,ether extract content of muscle in EUL2 group w ere significantly increased( P<0.05),but muscle shear force in EUL1 group was significantly reduced( P<0.05). 4) Compared with CTL group,saturated fatty acids( SFA) content of muscle w ent dow n slightly in EUL1 and EUL2 groups( P>0.05),w hile unsaturated fatty acids( UFA) content w as significantly increased in EUL1 and EUL2 groups( P<0.05),in which monounsaturated fatty acids( MUFA) and polyunsaturated fatty acids( PUFA) contents and UFA/SFA in EUL2 group w ere significantly increased( P < 0. 05). 5) Compared w ith CTL group,EUL could significantly dow n-regulate mRNA expression levels of lipid synthesis related enzyme [stearyl Co A desaturase 1( SCD1) ] and nuclear factors [sterol regulatory element-binding proteins 1 c( SREBP-1 c) and peroxisome proliferator-activated receptor γ( PPARγ) ] in liver( P < 0. 05),and could significantly up-regulate mRNA expression levels of lipid deposition related enzymes [carnitine palmityl transferase1 A( CPT1 A) and lipoproteinesterase( LPL) ] in liver( P< 0.05); compared w ith CTL group,liver SCD1 protein level in EUL2 group w as significantly decreased( P< 0.05). These changes indicate that EUL significantly affects lipid metabolism and muscle fatty acid composition of sheep by regulating gene expressions related to lipid synthesis and deposition.[Chinese Journal of Animal Nutrition,2017,29( 10) : 3635-3647]
出处
《动物营养学报》
CAS
CSCD
北大核心
2017年第10期3635-3647,共13页
CHINESE JOURNAL OF ANIMAL NUTRITION
基金
河南省科技厅科技惠民计划项目
信息化技术在杜仲羊生产中的应用(162207110009)
河南省现代农业产业技术体系专项基金(2013-14)
关键词
杜仲叶
脂肪代谢
血浆生化指标
脂肪酸组成
肝脏
基因表达
綿羊
Eucommia ulmoides leaves
lipid metabolism
plasma biochemical index
fatty acid composition
liver
gene response
sheep
