Bishop J E, Laurent G J
Department of Medicine, University College London, Rayne Institute, U.K.
Eur Heart J. 1995 May;16 Suppl C:38-44. doi: 10.1093/eurheartj/16.suppl_c.38.
Eighteen different collagen types have now been identified, at least five of which are found in the extracellular matrix of the heart. The interstitial collagens, types I and III are the most abundant components. Due to their tensile strength and arrangement in a network, surrounding and inter-connecting myocytes and capillaries, these collagens transmit forces throughout the myocardium, maintain cardiac structure during the cardiac cycle and contribute to the visco-elastic properties of the myocardium. Early application of isotopic techniques to assess turnover suggested that heart collagen, in contrast to cytoplasmic proteins, was virtually inert. The later development of more accurate methods for measuring its synthesis and degradation rates revealed that collagen turnover was quite rapid and that heart cells synthesize and degrade collagens throughout life. Thus, changes in the balance between synthesis and degradation may lead to changes in the composition of the collagen network, which may have marked effects on compliance, resulting in changes in heart function. Current research is focused on the role of mechanical forces and growth factors in the regulation of collagen metabolism. An understanding of the regulatory mechanisms involved in controlling collagen metabolism is fundamental to the development of agents that may reverse or prevent excess collagen deposition in cardiovascular diseases.
目前已鉴定出18种不同类型的胶原蛋白，其中至少有5种存在于心脏的细胞外基质中。I型和III型间质胶原蛋白是最丰富的成分。由于它们的抗张强度以及在网络中的排列方式，围绕并连接心肌细胞和毛细血管，这些胶原蛋白在整个心肌中传递力量，在心动周期中维持心脏结构，并有助于心肌的粘弹性。早期应用同位素技术评估周转率表明，与细胞质蛋白相比，心脏胶原蛋白实际上是惰性的。后来开发出更精确的方法来测量其合成和降解速率，结果显示胶原蛋白周转相当迅速，并且心脏细胞在整个生命过程中都在合成和降解胶原蛋白。因此，合成与降解之间平衡的变化可能导致胶原蛋白网络组成的改变，这可能对顺应性产生显著影响，从而导致心脏功能的变化。目前的研究集中在机械力和生长因子在胶原蛋白代谢调节中的作用。了解控制胶原蛋白代谢的调节机制是开发可能逆转或预防心血管疾病中过量胶原蛋白沉积的药物的基础。
