Adipocyte forming activity and its regulation, which affect obesity development.

肥胖是脂肪组织发育异常，是一个受多种因素调控的高度复杂的现象。最近的几项研究表明，即使在成年人中，脂肪细胞的数量也可能增加。根据这些结果，推测脂肪组织中存在调节脂肪组织发育形成肥胖的未知因素。因此，我们利用瑞士小鼠胚胎中建立的3T3-L1细胞系和遗传性肥胖小鼠附睾脂肪垫中建立的Ob1771细胞系作为我们建立的完全确定的无血清培养基中的前脂肪细胞模型，研究了控制前脂肪细胞增殖的机制。我们发现在大鼠脂肪组织中存在一种蛋白质生长因子（m.w.25 000），它能特异性地促进前脂肪细胞的增殖。这种蛋白质因子似乎对能量摄入起作用。因此，脂肪组织中的前脂肪细胞生长因子可能在控制系统中起关键作用，并有助于脂肪组织的发育。

Obesity of abnormal adipose tissue development, is a highly complex phenomenon regulated by many factors. Several recent studies suggested that the number of adipocytes may increase even in adults. From these results, it has been speculated that unknown factors which regulate adipose tissue development forming obesity are present in adipose tissue. Therefore, we investigated the mechanism controlling proliferation of preadipocytes using 3T3-L1, established form Swiss mouse embryos, and Ob1771, established from the epididymal fat pads of genetic obese mouse, cell lines as models of preadipocytes in completely defined serum free medium establised by us. We found the presence of a protein growth factor (M.W.25,000) IN rat adipose tissue which specifically permits the proliferation of preadipocytes. This protein factor appears to function in response to energy intake. Thus preadipocyte growth factor in adipose tissue may play a key role in the controlled system and contribute to the development of adipose tissue.