Dell'orco R T, Guthrie P L
Mech Ageing Dev. 1976;5(6):399-407. doi: 10.1016/0047-6374(76)90037-3.
Protein synthesis and turnover were measured in human diploid fibroblasts which were arrested in an essentially nonmitotic state by reducing the serum concentration in the incubation medium to 0.5%. Through the first 4 days of the arrested period both early and late passage cells lost about 20% of their cellular protein. There was a reduction in the rate of protein synthesis at both passage levels during this period, but there was no significant age-related difference in the synthetic rate or the rate of protein turnover. After day 4 both early and late passage cells maintained a constant protein content, but late passage cells did this while processing more protein through faster rates of both synthesis and turnover than did early passage cells. These results support those theories of cellular senescence which predict altered protein metabolism as a major consequence of the aging process.
在人二倍体成纤维细胞中测量蛋白质合成和周转情况，这些细胞通过将孵育培养基中的血清浓度降至0.5%而停滞在基本非有丝分裂状态。在停滞期的前4天，早期和晚期传代细胞均损失了约20%的细胞蛋白质。在此期间，两个传代水平的蛋白质合成速率均降低，但合成速率或蛋白质周转速率在年龄上没有显著差异。4天后，早期和晚期传代细胞均维持恒定的蛋白质含量，但晚期传代细胞在维持蛋白质含量恒定的同时，其蛋白质合成和周转速率均比早期传代细胞更快，因而处理的蛋白质更多。这些结果支持了细胞衰老理论，这些理论预测蛋白质代谢改变是衰老过程的主要后果。
