Wright J T, Hausman G J
USDA, ARS, R. B. Russell Research Center, Animal Physiology Research Unit, Athens, Georgia 30613, USA.
In Vitro Cell Dev Biol Anim. 1995 May;31(5):404-8. doi: 10.1007/BF02634290.
Insulinlike growth factor-1 (IGF-1) is both adipogenic and mitogenic to preadipose cell lines as well as primary stromalvascular (SV) cells. The precise effect of IGF-1 on primary preadipocytes per se, however, has not been elucidated directly. In this study, primary porcine preadipocytes were exposed to IGF-1 while at three culture densities. The proportion of replicating preadipocytes was determined by labeling cells with an antiadipocyte/preadipocyte monoclonal antibody (MAb) concomitant with DNA measurement with propidium iodide. Flow cytometric analysis revealed that different seeding densities did not affect the relative proportion of preadipocytes (AD-1 positive) in cultures. However, IGF-1 treatment increased the proportion of preadipocytes at all densities but to a greater extent in more dense cultures. The resultant number of fat cell clusters formed was greater at higher densities and on IGF-1 treatment. The proportion of replicating cells in cultures decreased with increasing density. IGF-1 significantly increased replication at all densities and increased the number of replicating preadipocytes to the same extent independent of density. These results provide direct evidence of hormonal regulation of primary preadipocyte replication.
胰岛素样生长因子-1（IGF-1）对脂肪前体细胞系以及原代基质血管（SV）细胞具有促脂肪生成和促有丝分裂作用。然而，IGF-1对原代前脂肪细胞本身的确切作用尚未得到直接阐明。在本研究中，将原代猪前脂肪细胞在三种培养密度下暴露于IGF-1。通过用抗脂肪细胞/前脂肪细胞单克隆抗体（MAb）标记细胞并同时用碘化丙啶进行DNA测量来确定复制前脂肪细胞的比例。流式细胞术分析表明，不同的接种密度不影响培养物中前脂肪细胞（AD-1阳性）的相对比例。然而，IGF-1处理在所有密度下均增加了前脂肪细胞的比例，但在密度更高的培养物中增加的程度更大。在更高密度和IGF-1处理下形成的脂肪细胞簇数量更多。培养物中复制细胞的比例随密度增加而降低。IGF-1在所有密度下均显著增加复制，并将复制前脂肪细胞的数量增加到相同程度，与密度无关。这些结果提供了原代前脂肪细胞复制受激素调节的直接证据。
