中文摘要：

【目的】探讨猪肌内脂肪细胞与皮下脂肪细胞的基因表达差异。【方法】通过改进的胶原酶消化法,分别从猪（大×长二元杂）皮下脂肪组织和背最长肌肌肉组织中分离脂肪前体细胞,用850nmol·L-1胰岛素和50nmol·L-1地塞米松诱导细胞分化,采用油红O提取法测定细胞分化过程中的聚酯水平。同时采用实时荧光定量PCR方法检测细胞分化过程中的转录调控因子基因（PPARγ、C/EBPβ与SREBP-1）、脂肪合成酶相关基因（GPDH、ACC和SCD-1）、脂肪酸转运相关基因（LPL、FAT与AP2）以及肌肉旁分泌因子受体基因（ACVR2B、IL-6R和IGF-1R）的表达模式。【结果】猪肌内脂肪前体细胞诱导后聚酯的速度快于皮下脂肪前体细胞。与此相似,肌内脂肪前体细胞中PPARγ、SREBP-1、SCD-1、LPL、AP2和FAT的mRNA表达在分化后期均显著高于皮下脂肪细胞。肌肉旁分泌因子受体基因ACVR2B、IGF-IR和IL-6RmRNA在皮下脂肪前体细胞随分化程度的增加其表达水平逐渐降低,但肌内脂肪前体细胞ACVR2B却在诱导后不断上调。【结论】建立了猪肌内和皮下脂肪前体细胞的原代培养模型,发现在离体培养条件下猪肌内脂肪前体细胞比皮下脂肪前体细胞具有更强的分化聚酯能力。从在体情况下肌内脂肪的沉积量少,沉积时间晚等现象可以推测肌内脂肪前体细胞的分化有可能受到肌肉旁分泌因子的局部抑制。

英文摘要：

[ Objective ] To investigate the differential mRNA expression between intramuscular and subcutaneous adipocytes of pig. [ Method] Conventional collagenase-based procedures were modified to harvest preadipocytes from longissimus dorsi muscle and subcutaneous adipose tissue of neonatal piglets （Large-White Landrace） respectively, and the preadipocytes were then exposed to DMEM/F12 medium containing 5% new born bovine serum （NBS）, 850 nmol·L^-1 insulin （Ins） and 50 nmol·L^-1 dexamethasone （Dex）. The concentrations of intracellular triglyceride were measured by Oil Red O staining. The mRNA expression level of genes involved in adipogenesis, such as peroxisome proliferator-activated receptors γ （PPAR γ）, CCAAT/enhancer binding protein β （C/EBP β）, sterol regulatory element binding protein-1 （SREBP-1）, acetyl-CoA earboxylase （ACC）, stearoyl-CoA （A9） desaturase 1 （SCD-1）, lipoprotein lipase （LPL）, fatty acid translocase （FAT）, and adipocyte fatty acid binding protein （aP2） in the two preadipocytes were compared by real-time PCR, so were those of cytokine receptors, such as activin receptor 2B （ACVR2B）, interleukin-6 receptor （IL-6R）, insulin-like growth factor-1 receptor （IGF-1R）. [Result] The results showed that intracellular triglyceride concentrations of intramuscular preadipocytes increased more dramatically than that of subcutaneous preadipocytes during cell differentiation, paralleling with the higher mRNA expression levels of PPAR y, SREBP-1, SCD-1, LPL, AP2 and FAT in intramuscular preadipocytes. The mRNA expression levels of ACVR2B, IL-6R and 1GF-IR were significantly down-regulated in subcutaneous preadipocytes after induction, while that of ACVR2B was gradually up-regulated in intramuscular preadipocytes. [ Conclusion ] These results indicated that, unlike the pattern of fat deposition in vivo, intramuscular preadipocytes cultured in vitro showed a higher capability of differentiation than that of subcutaneous preadipocytes. These may be