Yoshinari N, Kameyama Y, Aoyama Y, Nishiyama H, Noguchi T
Department of Periodontology, School of Dentistry, Aichi-Gakulin University, Nagoya, Japan.
J Periodontal Res. 1994 Nov;29(6):393-400. doi: 10.1111/j.1600-0765.1994.tb01240.x.
The effects of long-term methotrexate (MTX)-induced neutropenia on the periodontal lesion in rats were investigated histologically, histometrically and bacteriologically. A nylon thread was inserted into the interdental gingiva between the 1st and 2nd right maxillary molars of the animals 3 weeks before an application of MTX. The animals were then divided into Groups A and B. Group B were injected intraperitoneally with 1.0 mg/kg of MTX 3 times per week for 9 weeks. Group A received saline as a control. Five animals were killed at the 1st, 3rd, 5th, 7th, and 9th week. In Group A, the neutrophils did not decrease during these 9 weeks. In Group B, however, the neutrophils decreased during the 3rd to 9th week. Whereas the experimental side of Group A showed only moderate alveolar bone resorption between the 7th and 9th week, [in Group B] a marked alveolar bone resorption occurred in Group B occurred in the same period. Alveolar bone loss in the experimental side of Group B was significantly greater (p < 0.01) than in Group A in the 7th to 9th weeks. The percentage of gram-negative rods increased in both control and experimental sides of Group at the 9th week. The results of the present study indicate that neutropenia is induced by a long-term application of MTX in rats and that alveolar bone destruction increases as time goes by in the area where a nylon thread was inserted.
本研究通过组织学、组织计量学和细菌学方法，探讨了长期使用甲氨蝶呤（MTX）诱导的中性粒细胞减少对大鼠牙周病变的影响。在应用MTX前3周，将尼龙线插入动物右上颌第一和第二磨牙之间的牙龈乳头。然后将动物分为A组和B组。B组每周腹腔注射1.0mg/kg的MTX，共9周，每周3次。A组注射生理盐水作为对照。在第1、3、5、7和9周处死5只动物。A组在这9周内中性粒细胞未减少。然而，B组在第3至9周中性粒细胞减少。A组实验侧在第7至9周仅表现为中度牙槽骨吸收，而B组在同一时期出现明显的牙槽骨吸收。B组实验侧牙槽骨丧失在第7至9周显著大于A组（p<0.01）。第9周时，A组对照侧和实验侧革兰氏阴性杆菌的百分比均增加。本研究结果表明，长期应用MTX可诱导大鼠中性粒细胞减少，且在插入尼龙线的区域，牙槽骨破坏随时间推移而增加。
