Bowman P D, Meek R L, Daniel C W
Mech Ageing Dev. 1976 Jul-Aug;5(4):251-7. doi: 10.1016/0047-6374(76)90025-7.
The ability of cells from young and old cultures of WI38 human fibroblasts to undergo unscheduled DNA synthesis was studied. Following inhibition of semi-conservative synthesis in media lacking arginine and containing a hydroxyurea block, cells were irradiated with u.v. light and repair replication was measured by determination of specific activity of DNA and by autoradiography. Unscheduled DNA synthetic capacity was significantly reduced in old cultures. Quantitation of silver grains revealed that this reduction was a result of decreased repair activity by individual cells, which correlated well with a similar decrease in the proportion of dividing cells in the population. This observation that unscheduled DNA synthesis is reduced in older cells is in apparent contradiction to some earlier reports, and the failure of other investigators to identify aging changes in repair capacity is discussed in relation to differences in experimental procedure.
研究了WI38人成纤维细胞年轻培养物和衰老培养物中的细胞进行非预定DNA合成的能力。在缺乏精氨酸且含有羟基脲阻断剂的培养基中抑制半保留合成后，用紫外线照射细胞，并通过测定DNA的比活性和放射自显影来测量修复复制。衰老培养物中的非预定DNA合成能力显著降低。银颗粒定量显示，这种降低是单个细胞修复活性降低的结果，这与群体中分裂细胞比例的类似降低密切相关。衰老细胞中非预定DNA合成减少这一观察结果与一些早期报告明显矛盾，并且结合实验程序的差异讨论了其他研究人员未能识别修复能力的衰老变化的原因。
