Kantomaa T, Tuominen M, Pirttiniemi P
Institute of Dentistry, University of Oulu, Finland.
J Dent Res. 1994 Jun;73(6):1150-6. doi: 10.1177/00220345940730060401.
The effects of mechanical factors on the growth of the mandibular condyle were studied by monitoring the maturation of the mesenchymal cells in 55 rats. Thirty-five animals were fed normal pellet food, and 20 were fed a soft diet and their incisors were cut regularly. 3H-thymidine was injected intraperitoneally three days before death at 18, 23, or 33 days. Histologic sections showed the most advanced 3H-thymidine-labeled cells to occur deep in the cartilage, in the lower hypertrophic cell layer in anterior and posterior regions of the condyle, and in the upper hypertrophic cell layer in the superior region at the age of 18 days. A distinct difference in the maturation state of the labeled cells could also be observed between these regions. In animals fed a soft diet, maturation was slower in the superior region of the condyle and faster in the posterior region than in the normal rats. The rate at which cells stepped out of the proliferating cell pool was measured by use of monoclonal antibodies against proliferating cell nuclear antigen. The ratio between labeled cells in the proliferating cell layer and the number of labeled cells beneath it was greater in control animals than in the soft-diet animals. The rate of differentiation and maturation of mesenchymal cells into chondrocytes seems to be controlled by mechanical factors.
通过监测55只大鼠间充质细胞的成熟情况，研究了机械因素对下颌髁突生长的影响。35只动物喂食正常颗粒食物，20只喂食软食且定期剪牙。在18、23或33天处死前三天腹腔注射3H-胸腺嘧啶核苷。组织学切片显示，在18天时，最先进的3H-胸腺嘧啶核苷标记细胞出现在软骨深部、髁突前后区域的下部肥大细胞层以及上部区域的上部肥大细胞层。这些区域之间标记细胞的成熟状态也存在明显差异。在喂食软食的动物中，髁突上部区域的成熟较慢，后部区域的成熟比正常大鼠快。通过使用抗增殖细胞核抗原的单克隆抗体来测量细胞从增殖细胞池中出来的速率。对照动物中增殖细胞层中标记细胞与下方标记细胞数量的比值高于软食动物。间充质细胞向软骨细胞分化和成熟的速率似乎受机械因素控制。
