异丙肾上腺素对大鼠正畸牙移动的影响

Isoproterenol accelerates the movement of the orthodontic tooth in rats

目的异丙肾上腺素(ISO)激动β2-肾上腺素受体加强破骨细胞生成反应,从而加速骨的吸收。文中研究β-肾上腺素受体激动剂ISO对大鼠正畸牙移动的影响。方法选取40只8周龄的SD雌性大鼠,以50g力近移大鼠右上第一磨牙,随机数字表法分成ISO组和对照组,分别腹腔注射ISO[5 mg/(kg·d)]和等量的等渗盐水,在加力第0、7、14、21天每组各处死5只,测量右上第一磨牙近中移动距离,HE染色观察牙周组织变化,TRAP染色计数右上第一磨牙近中根压力侧破骨细胞。结果正畸加力第7、14、21天,对照组牙移动距离为(0.40±0.07) mm、(0.62±0.06) mm、(0.85±0.07) mm,ISO组牙移动距离分别是(0.52±0.04) mm、(0.84±0.05) mm、(1.11±0.15) mm,ISO组移动距离明显增加(P<0.05); HE染色示加力第14天压力侧牙槽骨吸收最显著,加力第21天张力侧牙槽骨有明显新骨形成; TRAP染色示ISO组第7、14、21天ISO组破骨细胞数[(13.8±3.3、24±6.3、18.8±2.6)个]大于对照组[(9.6±1.9、14.6±3.7、10.4±3.1)个],差异有统计学意义(P<0.05)。结论ISO可以增加破骨细胞数量,从而加速正畸牙的移动。

Objective Isoproterenol （ISO） stimulates the β 2 -adrenoceptor to enhance osteoclast formation, thus accelerating bone resorption. This study was to explore the effect of β-adrenoceptor agonist ISO on orthodontic tooth movement in rats. Methods Forty healthy 8-week-old SD male rats with the upper right first molar moved proximally by 50 g force application were randomly divided into an ISO and a control group and injected intraperitoneally with ISO at 5 mg/kg/d and the same amount of saline, respectively. Five rats were sacrificed in each group after 0, 7, 14 and 21 days of orthodontic force application and the upper right maxillary harvested for measuring the distance of movement of the upper right first molar, observing the changes in the periodontal tissue by HE staining, and counting the osteoclasts by tartrate-resistant acid phosphatase staining （TRAP）. Results At 7, 14 and 21 days of orthodontic force application, the tooth movement distance was significantly larger in the ISO group （[0.52±0.04], [0.84±0.05] and [1.11±0.15] mm） than in the control （[0.40±0.07], [0.62±0.06] and [0.85±0.07] mm） （ P 〈0.05）. On HE staining, the alveolar bone resorption at the pressure side was the most significant at 14 days, and obvious new bone formation was observed in the alveolar bone at 21 days. At 7, 14 and 21 days, TRAP staining showed remarkably larger numbers of osteoclasts in the ISO group （13.8±3.3, 24±6.3 and 18.8± 2.6） than in the control （9.6±1.9, 14.6±3.7, 10.4±3.1） （ P 〈0.05）. Conclusion Isoproterenol can increase the number of osteoclasts and accelerate the movement of the orthodontic tooth in rats.