van de Venter M, Litthauer D, Oelofsen W
Department of Biochemistry, University of Port Elizabeth, South Africa.
J Cell Biochem. 1994 Jan;54(1):1-10. doi: 10.1002/jcb.240540102.
Adipocyte precursors from the stromal vascular fraction of human adipose tissue were allowed to differentiate in serum-free defined medium, whereafter their catecholamine stimulated lipolytic response was compared to that of mature isolated human adipocytes. Seventy-five to ninety percent of the fibroblast-like cells accumulated lipid droplets and glycerol-3-phosphate dehydrogenase activities of 1,000-2,800 mU/mg protein were measured in cell homogenates of differentiated cells. Lipolysis could be stimulated by both isoproterenol and norepinephrine in both differentiated preadipocytes as well as mature adipocytes. The results obtained with beta-adrenergic agents suggested the presence of a higher affinity receptor in differentiated preadipocytes as compared to mature adipocytes. Mature adipocytes responded well to beta-adrenergic agents, but no antilipolytic alpha 2-adrenergic response was observed in the differentiated preadipocytes. The presence of Gi proteins in the differentiated preadipocytes was suggested by the antilipolytic effect of adenosine as well as the lipolytic activity generated by pertussis toxin. In conclusion, our medium supported the differentiation of a very high percentage of human preadipocytes which developed a sensitive beta-adrenergic lipolytic response but which lacked an alpha 2-adrenergic antilipolytic response.
使人脂肪组织基质血管成分中的脂肪细胞前体在无血清限定培养基中分化，然后将其儿茶酚胺刺激的脂解反应与成熟的分离人脂肪细胞的反应进行比较。75%至90%的成纤维细胞样细胞积累了脂滴，在分化细胞的细胞匀浆中测得甘油-3-磷酸脱氢酶活性为1000 - 2800 mU/mg蛋白质。异丙肾上腺素和去甲肾上腺素均可刺激分化前脂肪细胞以及成熟脂肪细胞的脂解作用。β-肾上腺素能药物的实验结果表明，与成熟脂肪细胞相比，分化前脂肪细胞中存在亲和力更高的受体。成熟脂肪细胞对β-肾上腺素能药物反应良好，但在分化前脂肪细胞中未观察到抗脂解的α2-肾上腺素能反应。腺苷的抗脂解作用以及百日咳毒素产生的脂解活性提示分化前脂肪细胞中存在Gi蛋白。总之，我们的培养基支持了非常高比例的人前脂肪细胞的分化，这些细胞产生了敏感的β-肾上腺素能脂解反应，但缺乏α2-肾上腺素能抗脂解反应。
