Mohr W, Wessinghage D, Lenschow E
Z Rheumatol. 1980 Mar-Apr;39(3-4):55-73.
The biochemical defect leading to alcaptonuria is well known. However, the pathogenesis of ochronotic arthropathy is poorly understood. The present ultrastructural study elucidated the localization of ochronotic pigment in the articular cartilage and evidence was found that suggests a pathway for cartilage destruction and further degradation. The amount of ochronotic pigment enlarged with increasing distance from chondrocytes. Pigment was neither seen in chondrocytes nor in the immediate vicinity of the chondrocytic lacunae. The interfibrillar localization as well as the preferential deposits in the deeper zone of the cartilage may indicate a binding of ochronotic pigment to proteoglycans of the cartilage. It is assumed that altered proteoglycans are responsible for the increased fragility of articular cartilage leading to cartilage fragmentation. Fragments of ochronotic cartilage are phagocytosed by connective tissue cells. Incomplete digestion of ochronotic pigment results in the formation of ochronotic residual bodies in these cells.
导致尿黑酸尿症的生化缺陷已为人熟知。然而，褐黄病性关节病的发病机制却知之甚少。目前的超微结构研究阐明了褐黄病色素在关节软骨中的定位，并发现了提示软骨破坏及进一步降解途径的证据。褐黄病色素的量随着与软骨细胞距离的增加而增多。在软骨细胞及软骨细胞腔隙的紧邻区域均未发现色素。纤维间定位以及在软骨深层区域的优先沉积可能表明褐黄病色素与软骨蛋白聚糖结合。据推测，蛋白聚糖改变是导致关节软骨脆性增加从而引起软骨碎裂的原因。褐黄病软骨碎片被结缔组织细胞吞噬。褐黄病色素消化不完全导致这些细胞中形成褐黄病残余小体。
