McAnulty R J, Laurent G J
Coll Relat Res. 1987 Jun;7(2):93-104. doi: 10.1016/s0174-173x(87)80001-8.
Collagen turnover is now known to occur more rapidly in body tissues than traditionally believed, but the kinetics and mechanisms for degradation are still poorly understood. Here we measure collagen synthesis rates and the proportion of newly synthesized collagen (probably procollagen) which is rapidly degraded, in tissues of the adult rat after injection of [14C]-proline with a large "flooding" dose of unlabelled proline. Incorporation of [14C]-proline into lung, heart, skeletal muscle and skin collagen and its appearance as hydroxy [14C]-proline, free or in small molecular weight moieties, at various times up to one hour, suggested extremely rapid synthesis and degradation for some tissues of the adult rat. Values in heart, lung, skeletal muscle and skin (with the proportion of degradation of newly synthesized collagen shown in parentheses) were 5.2 +/- 0.7%/day (53 +/- 5%), 9.0 +/- 0.7%/day (37 +/- 2%), 2.2 +/- 0.3%/day (38 +/- 7%) and 4.4 +/- 1.3%/day (8.8 +/- 0.5%). These data provide in vivo evidence, which are consistent with the observation in isolated cells, that a proportion of newly synthesized collagen is degraded rapidly, and probably intracellularly, after its synthesis. They also indicate that collagen may be synthesized and degraded rapidly in normal rat tissues, but the mean turnover rates and the proportions of collagen degraded intracellularly vary widely between tissues.
现在已知胶原蛋白在身体组织中的周转比传统认为的要快，但降解的动力学和机制仍知之甚少。在此，我们在给成年大鼠注射[14C] - 脯氨酸并给予大量“饱和”剂量未标记脯氨酸后，测量成年大鼠组织中胶原蛋白的合成速率以及快速降解的新合成胶原蛋白（可能是前胶原蛋白）的比例。在长达一小时的不同时间点，[14C] - 脯氨酸掺入肺、心脏、骨骼肌和皮肤胶原蛋白中，并以游离或小分子部分形式出现的羟基[14C] - 脯氨酸表明，成年大鼠的某些组织中合成和降解极其迅速。心脏、肺、骨骼肌和皮肤的值（括号内为新合成胶原蛋白的降解比例）分别为5.2±0.7%/天（53±5%）、9.0±0.7%/天（37±2%）、2.2±- 0.3%/天（38±7%）和4.4±1.3%/天（8.8±0.5%）。这些数据提供了体内证据，与在分离细胞中的观察结果一致，即一部分新合成的胶原蛋白在合成后迅速降解，并且可能在细胞内降解。它们还表明，胶原蛋白在正常大鼠组织中可能快速合成和降解，但平均周转率以及细胞内降解的胶原蛋白比例在不同组织之间差异很大。
