Sato M, Grasser W
Department of Bone Biology and Osteoporosis Research, Merck Sharp and Dohme Research Laboratories, West Point, PA 19486.
J Bone Miner Res. 1990 Jan;5(1):31-40. doi: 10.1002/jbmr.5650050107.
The bisphosphonates 4-amino-1-hydroxybutylidene-1,1-bisphosphonic acid (ABP), 3-amino-1,1-hydroxypropane-1,1-diphosphonic acid (APD), and 1-hydroxyethane-1,1-diphosphonic acid (EHDP) were compared for their ability to inhibit the osteoclastic resorption of bone in culture. This was achieved by measuring the effect of bisphosphonate concentration on the number of resorption pits formed and the total area of resorption. During this analysis, a new application of reflected polarized light microscopy was developed that has advantages over other microscopy techniques, including scanning electron microscopy (SEM), as applied to the analysis of resorbed bone surfaces. Based on area analysis, the bisphosphonates were effective for the range 10(-7)-10(-8) M, with ABP about two to five times more effective than EHDP or APD. Similar data were obtained by counting the number of resorption pits but with EC50 10 times higher. At lower concentrations (10(-9) M), bisphosphonates may enhance the formation of resorption pits. APD was found to be more toxic (10 times) than ABP or EHDP to osteoclasts and mononuclear cells, but toxic concentrations were at least 10(2) times higher than the resorption EC50. These data plus immunofluorescence, SEM, and transient incubation experiments show that it is the bisphosphonate-bone complex that directly inhibits the excavation of resorption pits by mature osteoclasts. The mechanism of action does not appear to require inhibition of osteoclast differentiation or toxic elimination of osteoclasts. Bisphosphonates, however, subtly affect the cytoskeleton of osteoclasts.
比较了双膦酸盐4-氨基-1-羟基亚丁基-1,1-双膦酸（ABP）、3-氨基-1,1-二羟丙烷-1,1-二膦酸（APD）和1-羟基乙烷-1,1-二膦酸（EHDP）在培养物中抑制破骨细胞骨吸收的能力。这是通过测量双膦酸盐浓度对形成的吸收陷窝数量和吸收总面积的影响来实现的。在该分析过程中，开发了一种反射偏振光显微镜的新应用，它比其他显微镜技术（包括扫描电子显微镜（SEM））在用于分析吸收骨表面方面具有优势。基于面积分析，双膦酸盐在10⁻⁷ - 10⁻⁸ M范围内有效，ABP的有效性约为EHDP或APD的2至5倍。通过计数吸收陷窝数量获得了类似的数据，但半数有效浓度（EC50）高10倍。在较低浓度（10⁻⁹ M）下，双膦酸盐可能会增强吸收陷窝的形成。发现APD对破骨细胞和单核细胞的毒性比ABP或EHDP大（10倍），但毒性浓度至少比吸收EC50高10²倍。这些数据加上免疫荧光、SEM和短暂孵育实验表明，直接抑制成熟破骨细胞挖掘吸收陷窝的是双膦酸盐 - 骨复合物。作用机制似乎不需要抑制破骨细胞分化或对破骨细胞进行毒性清除。然而，双膦酸盐会微妙地影响破骨细胞的细胞骨架。
