Barone-Varelas J, Schnitzer T J, Meng Q, Otten L, Thonar E J
Department of Biochemistry, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612.
Connect Tissue Res. 1991;26(1-2):101-20. doi: 10.3109/03008209109152167.
Articular cartilage explants from bovine calf and steer were cultured for up to 19 days in medium with or without 20% fetal bovine serum (FBS) or insulin-like growth factor I (IGF-I). Lower concentrations of IGF-I were required for maximal stimulation of PG synthesis in calf than in steer. In calf, but not in steer, IGF-I was as effective as 20% FBS in stimulating PG synthesis. The stimulation by IGF-I or FBS was not accompanied at either age by alterations in the composition of the aggregating PGs nor by changes in the proportions of CS-rich and CS-poor PG subpopulations. In calf, IGF-I and FBS did not markedly alter the rate of turnover of either the 35S-PGs synthesized in vitro or the unlabeled PGs. In steer, explants cultured in the absence of IGF-I or FBS exhibited very fast rates of turnover and depletion of matrix PG with time; IGF-I and FBS were both effective in reducing the turnover rate of 35S-PGs and unlabeled PGs and in preventing PG depletion.
取自牛犊和公牛的关节软骨外植体在含有或不含20%胎牛血清（FBS）或胰岛素样生长因子I（IGF-I）的培养基中培养长达19天。与公牛相比，牛犊中PG合成的最大刺激所需的IGF-I浓度更低。在牛犊而非公牛中，IGF-I在刺激PG合成方面与20% FBS一样有效。在两个年龄段中，IGF-I或FBS的刺激均未伴随聚集PG的组成变化，也未伴随富含CS和贫CS的PG亚群比例的改变。在牛犊中，IGF-I和FBS均未显著改变体外合成的35S-PG或未标记PG的周转速率。在公牛中，在无IGF-I或FBS的情况下培养的外植体随着时间推移表现出非常快的基质PG周转和消耗速率；IGF-I和FBS在降低35S-PG和未标记PG的周转速率以及防止PG消耗方面均有效。
