自由基在大骨节病病理过程中的作用 Ⅵ.活性氧自由基对Ⅰ型胶原蛋白的损伤以及在损伤的胶原蛋白中的羟基磷灰石的矿化过程

THE ROLE OF FREE RADICALS IN THE PATHOLOGICAL PROCESS OF KASCHIN-BECK DISEASE Ⅵ.DAMAGE OF TYPE Ⅰ COLLAGEN INDUCED BY ACTIVE OXYGEN FREE RADICALS AND THE MINERALIZATION OF HYDROXYAPATITE IN THE DAMACED COLLAGEN

研究了氧自由基对Ⅰ型胶原蛋白造成的损伤以及在损伤的胶原蛋白存在下羟基磷灰石(HAP)的矿化过程。结果表明,黄嘌呤氧化酶系统的作用及^(50)CO照射均引起Ⅰ型胶原蛋白的降解,导致胶原纤维的破坏。用恒pH法研究了Ⅰ型胶原蛋白存在下,HAP在过饱和溶液中成长的动力学,发现Ⅰ型胶原蛋白促进结晶形成,经粒度分布和逆流扩散结晶研究,表明这种促进以对成核的促进为主。这提示,Ⅰ型胶原蛋白的氧化性降解可能是大骨节病发展过程的一个因素。

The action of oxygen free radicals on type Ⅰ collagen was studied. The results show that xanthineoxidase system and ^(60)Co irradiation both cause the degradation of collagen and the corruption of colla-gen fibers. By pH-static method, the kinetics of HAP crystal formation in presence of intact or dama-ged type Ⅰ collagen was studied. By comparing the kinetic parameters thus determined, it was foundthat type Ⅰ collagen promote the crystal formation, but its main effect is due to the acceleration ofnucleation, as shown by the partical size distribution studies and the counter-current diffusion crystalli-zation studies If the added collagen has been damaged, the crystallization was found to be acceleratedfurther, but, in these cases, the agglomeration of the crystals is promoted as well. This result is discu-ssed as a factor in the pathological process of Kaschin-Beck disease.