著者

中村 靖 斉藤 茂 山崎 健一 柴崎 好伸 Yasushi NAKAMURA Shigeru SAITO Kenichi YAMASAKI Yoshinobu SHIBASAKI 昭和大学歯学部歯科矯正学教室 昭和大学歯学部歯科矯正学教室 昭和大学歯学部歯科矯正学教室 昭和大学歯学部歯科矯正学教室 Department of Orthodontics School of Dentistry Showa University Department of Orthodontics School of Dentistry Showa University Department of Orthodontics School of Dentistry Showa University Department of Orthodontics School of Dentistry Showa University

雑誌

日本矯正歯科学会雑誌 = The journal of Japan Orthodontic Society (ISSN:0021454X)

巻号頁・発行日

vol.54, no.3, pp.159-169, 1995-06

参考文献数

47

被引用文献数

4

---

矯正学的歯の移動時には, 歯槽骨を形成している細胞と歯根膜細胞が矯正力というmechanical stressに対してさまざまな反応を示すことが知られている.そこで本研究は同一外科矯正患者から同時に採取した下顎骨片と健全な下顎第一小臼歯から骨系細胞と歯根膜細胞を剥離して培養した.両細胞に間欠的遠心力(50∿250回転)を付与し, DNA合成能, 細胞内アルカリフォスファターゼ(ALPase)活性, サイクリックAMP(cAMP)産生量, プロスタグランディンE_2(PGE_2)産生量, インターロイキン6(IL-6)産生量, 骨吸収能を測定した.両細胞に付与した間欠的遠心力が上記測定項目に対してどのような影響を与えるかを検討し, あわせて両細胞の反応性の相違についても比較検討した.その結果, 1. DNA合成能および細胞内ALPase活性は, 250回転において両細胞とも有意に促進された.2. 骨系細胞において, 遠心力の付与によりすべての回転数でcAMPおよびPGE_2産生量が有意に抑制され, IL-6産生量に関しても50回転において抑制傾向があった.3. 歯根膜細胞においては, 遠心力を付与してもcAMP, PGE_2, IL-6の産生量がほとんど変化しなかった.4. 骨吸収能は遠心力を付与した培養上清を用いると両細胞とも150回転で有意に抑制された.以上のことから, DNA合成能と細胞内ALPase活性は高回転の間欠的遠心力に対して両細胞とも促進することが示された.また, 骨系細胞の骨吸収能はPGE_2, IL-6の影響を直接的に受けやすいが, 歯根膜細胞に関してはPGE_2, IL-6以外にも骨吸収能に影響を与える何らかの因子が存在することも示唆された.It has been shown that bone cells and periodontal ligament (PDL) cells have various responses to mechanical stress during orthodontic tooth movement. The following experiments were performed to compare the responses of these two cell types to mechanical stress. Cortical bone specimens derived from mandible and PDL of first premolars were obtained at the same time from the same patient undergoing surgical orthodontics. In the confluent phase, intermittent centrifugal forces (ICF) were applied to the cultured bone cells and PDL cells at 50∿250 rpm. After centrifugation, the cultured cells were used for the assays of DNA synthesis, alkaline phosphatase (ALPase) activity and cyclic AMP (cAMP) production, and the cultured media were used for the assays of prostaglandin E_2 (PGE_2) production, interleukin-6 (IL-6) production and bone resorption activity. The results were as follows : 1. ICF at 250 rpm significantly induced DNA synthesis and ALPase activity in each cell type. 2. In bone cells, the amounts of cAMP and PGE_2 were significantly decreased by ICF at all magnitudes of force tested, and those of IL-6 tended to be decreased by ICF at 50 rpm. 3. In PDL cells, the amounts of cAMP, PGE_2 and IL-6 were hardly changed by ICF at all magnitudes of force tested. 4. ICF at 150 rpm significantly inhibited the bone resorption activity in each cell type. These results suggested that DNA synthesis and ALPase activity are stimulated by high-speed ICF in each cell type. These results also suggested that bone resorption activity caused by ICF in bone cells was directly affected by PGE_2 and IL-6. However, in PDL cells, there may be agents that affect bone resorption activity other than PGE_2 and IL-6.