Kizuki Yuko
Fixed Prosthodontics, Department of Restorative Sciences, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University.
Kokubyo Gakkai Zasshi. 2009 Jun;76(2):91-9.
The objectives of this study were to elucidate the influence of occlusal hypofunction on the histological structure of periodontal ligament (PDL) and on the cell proliferation and alkaline phosphatase (ALP) activities of cultured PDL cells isolated from PDL. Forty-two male Wister rats were divided into three groups: two experimental groups and one untreated control group. Occlusal hypofunction was generated in the molar region in the experimental groups for 3 or 7 days. Paraffin sections of the upper molar region were stained with H.E. or ALP for light-microscope observation. PDL cells isolated from molars of each group were cultured for 7 days for cytological analyses. Cell proliferation (BrdU labeling) and ALP activity of the three groups were compared. Change in the width of the PDL space, loss of functional arrangement of PDL fibers and reduction of PDL cell number were observed among molars of the experimental groups compared with the control group. ALP activity was increased in the molar region where significant enhancement of bone morphogenesis had not yet occurred. The ratio of BrdU positive cells was significantly lower and ALP activity was higher than that of the control group among cultured cells from molars of the experimental groups and the control group. The results clearly showed that occlusal hypofunction alters the histological characteristics of PDL even in a short time. Occlusal hypofunction reduces the cell proliferation and increases the ALP activity of PDL cells. The influence of occlusal hypofunction memory on cells is retained for at least 7 days in vitro.
本研究的目的是阐明咬合功能减退对牙周韧带（PDL）组织学结构以及从PDL分离的培养PDL细胞的细胞增殖和碱性磷酸酶（ALP）活性的影响。42只雄性Wistar大鼠分为三组：两个实验组和一个未处理的对照组。在实验组的磨牙区域产生咬合功能减退，持续3天或7天。对上颌磨牙区域的石蜡切片进行苏木精-伊红（H.E.）或ALP染色，用于光学显微镜观察。对每组磨牙分离的PDL细胞进行培养7天，用于细胞学分析。比较三组的细胞增殖（BrdU标记）和ALP活性。与对照组相比，实验组磨牙间观察到PDL间隙宽度改变、PDL纤维功能排列丧失和PDL细胞数量减少。在尚未发生明显骨形态发生增强的磨牙区域，ALP活性增加。实验组磨牙培养细胞中BrdU阳性细胞的比例明显低于对照组，且ALP活性高于对照组。结果清楚地表明，即使在短时间内，咬合功能减退也会改变PDL的组织学特征。咬合功能减退会降低PDL细胞的增殖并增加其ALP活性。咬合功能减退记忆对细胞的影响在体外至少保留7天。
