Klyde B J, Hirsch J
J Lipid Res. 1979 Aug;20(6):691-704.
The intraperitoneal administration of [3H]thymidine to adult rats resulted in the rapid appearance of label in the adipocyte fraction of collagenase digests of adipose tissue. Low-speed centrifugation followed by freezing and slicing showed the label to be uniformly distributed in the adipocyte fraction. The presence of label in DNA was confirmed by hydrolysis with deoxyribonuclease and by inhibition of incorporation with hydroxyurea. Organelle fractionation revealed that the label was predominantly in nuclei, and radioautography showed that only a few adipocyte nuclei were labeled. The label in the adipocyte fraction could not be reduced by increased collagenase digestion or by trypsin treatment. Mixing of labeled adipocytes with unlabeled stroma did not result in decrease of label and addition of labeled stroma to unlabeled adipocytes did not cause significant transfer of radioactivity. Addition of [3H]thymidine to the collagenase digestion medium of unlabeled adipose tissue resulted in more incorporation by adipocytes than by stroma, suggesting the presence of a very rapidly proliferating cell type associated more with adipocytes than with stroma. In vivo turnover studies of labeled DNA indicated that there are two components in both adipocytes and stroma, a rapidly labeled component with a half-life of only several days and another with a half-life of several months. These experiments suggest that there is a rapidly proliferating cell type in adipose tissue, closely associated with mature adipocytes, that may be an adipocyte progenitor or may have some other unknown function.
给成年大鼠腹腔注射[³H]胸苷后，在脂肪组织胶原酶消化产物的脂肪细胞部分迅速出现放射性标记。低速离心后冷冻切片显示，标记物在脂肪细胞部分均匀分布。用脱氧核糖核酸酶水解以及用羟基脲抑制掺入，证实了DNA中存在标记物。细胞器分级分离显示，标记物主要存在于细胞核中，放射自显影表明只有少数脂肪细胞核被标记。增加胶原酶消化或用胰蛋白酶处理，都不能减少脂肪细胞部分的标记物。将标记的脂肪细胞与未标记的基质混合，标记物不会减少，将标记的基质添加到未标记的脂肪细胞中，也不会导致明显的放射性转移。向未标记脂肪组织的胶原酶消化培养基中添加[³H]胸苷，脂肪细胞比基质掺入更多，这表明存在一种增殖非常迅速的细胞类型，与脂肪细胞的关联大于与基质的关联。对标记DNA的体内周转研究表明，脂肪细胞和基质中都有两个成分，一个是快速标记的成分，半衰期仅为几天，另一个半衰期为几个月。这些实验表明，脂肪组织中存在一种增殖迅速的细胞类型，与成熟脂肪细胞密切相关，可能是脂肪细胞祖细胞，也可能具有其他未知功能。
