妊娠后期胎儿宫内生长受限对蒙古绵羊胎儿肝脏细胞外基质合成的影响

Effects of Fetal Intrauterine Growth Retardation during Late Pregnancy on Extracellular Matrix Synthesis in Fetal Liver of Mongolia Sheep

本试验旨在研究妊娠后期胎儿宫内生长受限(IUGR)对蒙古绵羊胎儿肝脏细胞外基质合成的影响。选择健康的、经同期发情和受孕的蒙古绵羊18只,随机分为3组,代谢能水平分别为0.175(R1组)、0.330(R2组)和0.670 MJ/(kg BW0.75·d)(自由采食组,C组),每组6个重复,每个重复1只羊。妊娠140 d时屠宰母羊,测定胎儿肝脏实质细胞数量及细胞外基质含量。结果表明:R1组胎儿肝脏重(P<0.01)、肝细胞数(P<0.05)、肝细胞核直径(P<0.01)以及Ⅰ型胶原(P<0.01)、Ⅲ型胶原(P<0.05)、Ⅳ型胶原(P<0.01)、层黏连蛋白(P<0.01)、透明质酸(P<0.05)、纤连蛋白含量(P<0.01)显著或极显著低于C组,且内皮细胞数显著高于C组(P<0.05);R2组胎儿肝脏重(P<0.05)、纤连蛋白含量(P<0.01)显著或极显著低于C组,而内皮细胞数显著高于C(P<0.05)。结果提示,妊娠后期营养限饲蒙古绵羊严重限制其胎儿肝脏生长发育,代谢能水平为0.175 MJ/(kg BW0.75·d)时,胎儿肝脏细胞外基质合成受到了严重影响,且发生肝纤维化修复反应;代谢能水平为0.330 MJ/(kg BW0.75·d)时,仅有胎儿肝脏纤连蛋白含量发生改变。

This study investigated the effects of fetal intrauterine growth retardation（IUGR） during late pregnancy on extracellular matrix synthesis in fetal liver of Mongolia sheep.Eighteen healthy Mongolia sheep with synchronization of estrus and conception were allocated to three groups with 6 replicates per group and 1 sheep per replicate.Metabolizable energy（ME） level was 0.175（R1 group）,0.330（R2 group） and0.670 MJ/（kg BW^0.75·d）（Ad libitum group,C group）,respectively.At day 140 of gestation,ewes were slaughtered to determine parenchyma cell number and extracellular matrix contents in liver of their fetuses.The results showed that liver weight（P〈0.01）,liver cell number（P〈0.05）,liver cell nucleus diameter（P〈0.01）,and the contents of collagen type I（P〈0.01）,collagen type Ⅲ（P〈0.05）,collagen type Ⅳ（P〈0.01）,laminin（P〈0.01）,hyaluronic acid（P〈0.05） and fibronectin（P〈0.01） in fetal liver of Rl group were significantly lower than those of C group,and endothelial cell number in fetal liver was significantly higher than that of C group（P〈0.05）;significantly higher fetal liver weight（P〈0.05） and fibronectin content（P〈0.01） were founded in R2 group compared to C group,and endothelial cell number in fetal liver was significantly enhanced in Rl group compared to C group（P〈0.05）.The results indicate that nutrition restriction during late pregnancy of Mongolia sheep restricts growth and development of fetal liver,and a serious impact on the synthesis of extracellular matrix is found when ME level is 0.175 MJ/（kg BW^0.75. d）,and liver fibrosis repair reaction also occurs;only the change of fibronectin content in liver fetal is found when ME level is0.330 MJ/（kg BW075.d）.