中文摘要：

目的研究高脂饮食对幼鼠生长及胰岛素样生长因子（IGF-I）表达的影响,闸明血清和肝脏组织IGF-I代谢紊乱与非酒精性脂肪性肝病（NAFLD）幼鼠生长迟缓的关系。方法 21日龄SD雄性大鼠40只,随机分成正常（N）组、高脂（HF）组。高脂饮食成功诱导NAFLD幼鼠造模成功后,测定血清IGF-I及胰岛素样生长因子结合蛋白-3（IGFBP-3）水平,采用RT-PCR与Western-blot检测肝脏IGF-I和IGFBP3的mRNA和蛋白表达。结果5周高脂饲料喂养后,高脂组幼鼠肝脏符合典型的NAFLD病理特征;与正常组相比,高脂组血清总胆固醇（TC）、血清高敏C反应蛋白、血清ALT及肝组织三酰甘油（TG）含量均显著升高（P均〈0.01）。高脂组幼鼠体质量、鼻-尾长度较正常组增长缓慢（P〈0.01）。胫骨长度和股骨长度两组差异无统计学意义;高脂组股骨的骨密度和骨矿含量均低于正常组（P均〈0.05）。高脂组幼鼠血清IGF-I和IGFBP-3均较正常组表达显著下降（P均〈0.01）;血清生长激素（GH）两组差异无统计学意义（P〉0.05）;高脂组肝脏组织IGF-I和IGFBP3 mRNA和蛋白表达水平与血清学结果一致。结论血清IGF-I浓度与大鼠鼻-尾长度、体质量呈正相关,长期高脂饮食幼鼠生长迟缓,可能与肝脏组织和血清IGF-I浓度减低有关。

英文摘要：

Objective To investigate the effects of high-fat feeding on growth and expression of insulin-like growth factor-Ⅰ（IGF-Ⅰ） level in young rats,and to illustrate the relationship between growth failure in young rats with non-alcoholic fatty liver disease（NAFLD）and IGF-I turbulence.Methods Forty SD young rats of 3 weeks old were randomly divided into two groups,normal group（N）and high-fat feeding group（HF）.The levels of serum IGF-I and insulin-like growth factor binding protein 3（IGFBP3）were determined in NAFLD rats induced by high fat feeding.The mRNA and protein level of IGF-I and IGFBP3 in liver tissue were measured by RT-PCR and Western-blot methods.Results The typical pathological change of NAFLD was observed in young rats induced by high-fat feeding for 5 weeks.The levels of total cholesterol（TC）,C-reactive protein（CRP）and alanine aminotransferase（ALT）were significantly higher in HF group than in N group（P 0.01）.The level of liver triglyceride（TG）was significantly higher in HF group than in N group（P 0.01）.The body weight and the nose-tail length were significantly decreased.The femoral and the tibial lengths were shorter in HF group than in N group,but this reduction was not significant.The femoral bone mineral density（BMD）and bone mineral content（BMC）were lower in HF group than in N group（P 0.05）.The levels of serum IGF-I and IGFBP3 were significantly lower in HF group than in N group.The liver tissue mRNA and protein level of IGF-I and IGFBP3 were significantly decreased in HF group than in N group（P 0.01）.The serum growth hormone（GH）level was lower in HF group than in N group,but this reduction was not significant.Conclusions Serum IGF-I is correlated with the nose-tail length and the weight.The growth restriction of young rats,induced by high-fat feeding,may be related to the decreased expression of IGF-I.