van't Veen S J, Hagen J W, van Ginkel F C, Prahl-Andersen B, Burger E H
Department of Orthodontics, Academic Center of Dentistry Amsterdam (ACTA), The Netherlands.
Bone. 1995 Nov;17(5):461-5. doi: 10.1016/8756-3282(95)00334-6.
The effects of intermittent hydrostatic compressive force (ICF; 13 kPa applied at 0.3 Hz frequency), as a substitute for moderate loading in vivo, on ossifying bone organ cultures, were evaluated by means of (histo)-morphometry. In earlier studies, biochemical tests have shown an increased 45Ca intake and an increased alkaline phosphatase activity in bone organ cultures that received ICF, suggesting that ICF promoted matrix mineralization. The purpose of this study was to examine whether an effect of ICF on mineralization can be described by means of histomorphometrical analysis. Fetal mouse metatarsal bone rudiments were cultured for 5 days in serum-free medium, with (experimental) or without (control) ICF. Linear measurements taken during culture demonstrated that the dark zone in the center of the rudiment, representing mineralized hypertrophic cartilage, became significantly longer in the group that received ICF when compared with the control group. This finding was in conformation with the former studies. Histological sections of the rudiments, stained with Goldner's trichrome method were used to study changes at the cellular level and to describe the position and relative amount of mineralizing cartilage matrix (defined as Goldner-positive matrix [GPM]). Histomorphometry demonstrated that ICF treatment significantly increased the length of the hypertrophic cartilaginous zone and enhanced the amount of GPM between the mineralizing hypertrophic chondrocytes. However, the total length of the zone containing GPM was not increased, nor was the future bone collar, consisting of a thin osteoid seam, lengthened by ICF. These data indicate that the cellular processes involved in chrondrocyte hypertrophy were accelerated by ICF, as well as the extracellular processes leading to matrix mineralization. The study supports the earlier conclusion that embryonic bone rudiments are sensitive to mechanical stimulation and that moderate loading promotes their ossification in vitro.
作为体内适度负荷的替代方法，间歇性流体静力压力（ICF；以0.3Hz频率施加13kPa压力）对骨化骨器官培养物的影响通过（组织）形态计量学进行评估。在早期研究中，生化测试表明，接受ICF的骨器官培养物中45Ca摄入量增加，碱性磷酸酶活性增强，这表明ICF促进了基质矿化。本研究的目的是通过组织形态计量学分析来检验ICF对矿化的影响。将胎鼠跖骨原基在无血清培养基中培养5天，一组施加（实验性）ICF，另一组不施加（对照组）ICF。培养期间进行的线性测量表明，与对照组相比，接受ICF的组中，代表矿化肥大软骨的原基中心暗区明显变长。这一发现与之前的研究一致。用Goldner三色法染色的原基组织切片用于研究细胞水平的变化，并描述矿化软骨基质（定义为Goldner阳性基质[GPM]）的位置和相对数量。组织形态计量学表明，ICF处理显著增加了肥大软骨区的长度，并增加了矿化肥大软骨细胞之间的GPM量。然而，含有GPM的区域总长度并未增加，由薄类骨质缝组成的未来骨环也未因ICF而延长。这些数据表明，ICF加速了软骨细胞肥大所涉及的细胞过程以及导致基质矿化的细胞外过程。该研究支持了早期的结论，即胚胎骨原基对机械刺激敏感，适度负荷可促进其体外骨化。
