Boskey A L, Bullough P G
Scan Electron Microsc. 1984(Pt 2):943-52.
Hydroxyapatite crystal deposition occurs physiologically in cartilage as a prelude to bone formation via endochondral ossification. Both extracellular molecules and organelles, and the chondrocytes themselves control the initial formation of hydroxyapatite, as well as the growth and orientation of the hydroxyapatite crystals. In this study pathologic calcium containing deposits from 48 patients (27 hydroxyapatite and 21 calcium pyrophosphate dihydrate) were subjected to crystallographic, histologic (light microscopy, scanning electron microscopy, transmission electron microscopy) and chemical analyses and compared to normal controls. It is suggested that both hydroxyapatite and calcium pyrophosphate dihydrate deposition involve elevations in ionic concentrations, exposure of mineral nucleators, and removal of mineral inhibitors. Peculiar to the matrices of pathologic deposits of hydroxyapatite are elevated concentrations of calcium acidic phospholipid phosphate complexes and lower concentrations of hexosamine while collagen (hydroxyprolin) and total lipid contents are not altered. Matrices of deposits of calcium pyrophosphate dihydrate were similar biochemically except that calcium acidic phospholipid phosphate complexes concentrations were not elevated.
羟基磷灰石晶体沉积在生理状态下发生于软骨，作为通过软骨内成骨形成骨骼的前奏。细胞外分子和细胞器以及软骨细胞本身都控制着羟基磷灰石的初始形成以及羟基磷灰石晶体的生长和取向。在本研究中，对48例患者（27例为羟基磷灰石，21例为二水焦磷酸钙）的病理性含钙沉积物进行了晶体学、组织学（光学显微镜、扫描电子显微镜、透射电子显微镜）和化学分析，并与正常对照进行了比较。结果表明，羟基磷灰石和二水焦磷酸钙沉积均涉及离子浓度升高、矿物成核剂暴露以及矿物抑制剂的去除。病理性羟基磷灰石沉积物基质的特点是酸性钙磷脂磷酸复合物浓度升高，己糖胺浓度降低，而胶原蛋白（羟脯氨酸）和总脂质含量未改变。二水焦磷酸钙沉积物的基质在生化方面相似，只是酸性钙磷脂磷酸复合物浓度没有升高。
