An Analysis of Adipocyte Differentiation in Vitro that Evaluates a Potency of Marbling Formation

牛肌内脂肪的积累是决定牛肉品质的一个重要因素。阐明牛肌内脂肪组织细胞发育成熟脂肪细胞是准确理解大理石花纹形成机制的一个更基础的问题。本研究旨在建立牛骨骼肌脂肪细胞前体细胞脂肪生成的培养体系，研究生长因子对脂肪细胞分化的影响，并探讨能否通过培养脂肪细胞的分化来估计肌内脂肪的数量和分布。（1）建立了从牛肌内脂肪组织来源的脂肪细胞前体细胞分化成脂肪细胞的培养体系，将前体细胞转移到MEX/Ham’s 12培养基（体积比1：1）的混合物中，含100 nM或1 uM地塞米松 ...更多信息 一种是170 nM胰岛素、10 μ g/ml转铁蛋白和1 nM三碘甲腺原氨酸，它们在补充有10%胎牛血清和1.5%猪胎提取物的DMEX培养基中汇合培养。(2)肌内脂肪细胞的分化和成熟是由地塞米松和胰岛素引起的，但不是它们中的每一个。(3)地塞米松对前体脂肪细胞的发育和成熟脂肪细胞的诱导是不可缺少的。在100 nM ~ 1 μ M浓度范围内，该因子对成脂肪细胞的生长和前体脂肪细胞的分化有较好的促进作用，而胰岛素对前体脂肪细胞向脂肪细胞的成熟有较好的促进作用。(4)肌内脂肪前体细胞体外分化为脂肪细胞的能力与牛骨骼肌大理石纹的数量和范围有关。(5)即使在来自14月龄日本黑阉牛背最长肌的脂肪细胞前体细胞的培养物中，也认识到脂肪细胞的分化和成熟。(6)肌内脂肪细胞的免疫细胞化学特征与肌内脂肪组织中的细胞与抗LPL抗体、抗波形蛋白抗体和因子VIII抗体呈阳性反应相对应。少

The accumulation of intramuscular fat in bovine has been an important factor in determining meat quality as a marbling. The elucidation of cells from bovine intramuscular adipose tissue developing mature adipocytes is a more fundamental problem to precisely understand the mechanisms of marbling formation. The research presented here was designed to establish the culture system of lipogenesis by adipocyte precursor cells isolated from bovine skeletal muscle, and to study the influence of growth factors on the adipose differentiation and determine whether the intramuscular fat quantity and distribution are estimated by the differentiation of adipocytes in cultures.The results presented in this study are as follows :(1) The culture system for adipocyte differentiation from adipocyte precursor cells derived from bovine intramuscular adipose tissue was established when the precursor cells were transferred in a mixture of MEX/Ham's 12 medium (1 : 1 by vol.) containing 100nM or 1uM dexamethas … More one, 170nM insulin, 10ug/ml transferrin and 1nM triiodothyronine after they became the confluent cultures in DMEX medium supplemented with 10% fetal bovine serum and 1.5% swine fetal extract.(2) Differentiation and maturation of intramuscular adipocytes were caused by the addition of both dexamethasone and insulin but not each of them.(3) Dexamethasone was indispensable to develop preadipocytes and induce mature adipocytes. Especially, the factor was more effective on the growth of adipoblasts and the differentiation of preadipocytes at a concentration of 100nM-1muM.On the other hand, insulin was more effective on the maturation of adipocytes from preadipocytes.(4) Developing ability into adipocytes from intramuscular adipocyte precursor cells in vitro was paralleled with the quantity and extension of marbling in bovine skeletal muscles.(5) The differentiation and maturation of adipocytes was recognized even in cultures of adipocyte precursor cells derived from longissimus muscle of 14 months old of Japanese Black steers.(6) The immunocytochemical characterization of intramuscular adipocytes developing in cultures corresponded with that of intramuscular adipose tissue in which the cells were positively reacted with anti-LPL antibody, anti-vimentin antibody and Factor VIII antibody. Less