EXTRACELLULAR PYROPHOSPHATE METABOLISM OF CHONDROCYTES

最近相当多的研究表明，关节内异常高， 无机焦磷酸盐（PPi）作为重要的代谢产物， 二水焦磷酸钙（CPPD）沉积疾病的缺陷， 骨关节炎 已确定carbohydrate是可能的主要来源 PPi的异常产生。 PPi活性升高 产生胞外酶，三磷酸核苷焦磷酸水解酶 （NTPPPH）在患者的软骨和滑液（SF）中均被发现 芝加哥警署的证词 SF NTPPPH活性与SF PPi相关 浓度在各种关节病，但它是不知道，如果NTPPPH 参与关节内PPi的产生。 初步实验表明，分离的猪软骨细胞表现出 ecto-NTPPPH活性和自发产生的PPi。 我们有部分 纯化NTPPPH从分离的软骨细胞的脱氧胆酸盐提取物， 阴离子交换层析 我们如何建议高度纯化猪 软骨细胞NTPPPH亲和层析并制备抗血清 家兔 沉淀的抗血清可以使免疫组织学 测定NTPPPH在关节组织中的分布。 如果抗血清 特异性阻断NTPPPH活性，我们希望确定 如果完整软骨细胞的胞外PPi加工依赖于 NTPPPH。

Considerable recent research has revealed abnormally high intra-articular production of inorganic pyrophosphate (PPi) as an important metabolic defect in calcium pyrophosphate dihydrate (CPPD) deposition disease and osteoarthritis. Cartilage has been identified as a probable major source of abnormal PPi production in these diseses. Elevated activity of the PPi generating ecto-enzyme, nucleoside triphosphate pyrophosphohydrolase (NTPPPH) is found in both cartilage and synovial fluid (SF) of patients with CPPD deposition. SF NTPPPH activity correlates with SF PPi concentration in a variety of arthropathies, but it is not known if NTPPPH participates in intra-articular PPi production. Preliminary experiments indicate isolated porcine chondrocytes exhibit ecto-NTPPPH activity and spontaneously elaborate PPi. We have partially purified NTPPPH from deoxycholate extracts of isolated chondrocytes by anion exchange chromatography. We how propose to highly purify porcine chondrocyte NTPPPH by affinity chromatography and prepare antisera in rabbits. A precipitating antiserum would allow immunohistologic determination of NTPPPH distribution in articular tissues. If an antiserum which specifically blocks NTPPPH activity is obtained, we hope to determine if extracellular PPi elaboration by intact chondrocytes is dependent on NTPPPH.