成年鲁西牛肌内前脂肪细胞的分离培养

建立牛肌内前脂肪细胞体外培养方法，旨在更深入地研究组成肌肉内脂肪组织的肌内前脂肪细胞的增殖分化特性及其影响因素。选取来自成年育肥鲁西黄牛第6与第7肋骨间的肌肉内脂肪组织，利用Ⅰ型胶原酶消化法分离获得牛肌内前脂肪细胞。培养出的细胞成分均一，增殖旺盛，分化率高，经形态学动态变化观察、生长曲线、油红O脂肪染色提取法及对胰岛素和地塞米松反应的测定，证明是功能活跃的前脂肪细胞，并在体外重现了其增殖分化过程，同时经染色体核型分析证明体外培养的细胞倍性正常，可以用于后续研究。本试验成功分离得到了成年育肥牛肌内前脂肪细胞，这为下一步研究肌内脂肪的沉积机制，改善牛肉品质奠定了基础。

Isolation and In vitro Culture of Intramuscular Preadipocyte from Luxi Adult Yellow Cattle

Three Luxi adult yellow steers were used to isolate and culture intramuscular preadipocyte in vitro and examine factors influencing their proliferation and differentiation. The intramuscular preadipocyte cells were taken from adipose tissues within muscles between sixth and seventh rib and cultured after digestion by collagenase I. The results showed that the separated cells were highly homogeneous, proliferative and double timed within 62 h. When the confluent preadipocytes were treated with differentiation medium, small lipid droplets began to appear on day 2 and the number of lipid droplets rapidly increased around the nuclei on day 6. Their dynamic morphological changes, growth curve, oil O staining, and reaction to insulin and dexamethasone all verified their preadipocyte identity. Under controlled conditions, the intramuscular preadipocytes replayed their proliferation and differentiation process in vitro, especially, the proportion of cultured diploid preadipocytes reached to more than 90% after 6 run of repeated cultures were performed. In conclusion, the current study confirms that functionally active preadipocytes indeed present within muscles of China adult local breed cattle. The cell strains will be potentially used as a useful model for further understanding of the mechanism by which the intramuscular adipose is deposed in the tissues, and for improving the beef quality based on local breed beef cattle.