全身应用催产素对骨质疏松大鼠种植体骨结合的影响

Efficacy of systemic administration of oxytocin on implant osseointegration in osteoporotic rats

目的探讨骨质疏松大鼠全身应用催产素对种植体骨结合的影响。方法 20只大鼠平均分成对照组和实验组,接受双侧卵巢切除术以建立骨质疏松模型。12周后,在每只大鼠的双侧股骨远中干骺端各植入1枚种植体,同时接受催产素全身用药,实验组皮下注射催产素(每天1 mg·kg-1),对照组注射生理盐水。用药4周后,观察8周,手术取出大鼠胫骨和带有种植体的股骨,采用显微CT和组织学染色观察大鼠胫骨的骨质疏松情况,用显微CT、组织学观察和推出试验评价骨结合效果。结果实验组与对照组相比,胫骨样本的骨小梁增多、密集,交织成网状,骨质疏松模型成功建立。实验组种植体周围的相对骨体积分数为0.35%±0.06%,骨结合率为67.25%±9.06%,最大推出力为(70.32±10.91)N,对照组的相对骨体积分数、骨结合率和最大推出力分别为0.11%±0.02%、43.25%±7.01%、(21.65±4.36)N,实验组较对照组均明显增加(P<0.05)。结论全身应用催产素可拮抗骨质疏松的负面影响,促进种植体愈合,对纯钛种植体的骨结合具有正向影响。

Objective This study investigated the effects of systemic administration of oxytocin （OT） in osteoporotic rats on implant osseointegration.Methods Twenty rats were randomly assigned to the control and experimental groups. Initially, the rats underwent bilateral ovariectomy. After 12 weeks, an osteoporosis model was established. Each rat received an implant at the distal and middle femoral metaphysis. Simultaneously, systemic administration was conducted with one group receiving subcutaneous injection of OT （1 mg·kg-1 per day）, whereas the other group received placebo injection. After treatment for 4 weeks, another surgery was conducted to remove the thigh bones from the rats containing the implants for an eight-week observation. With the employment of micro-CT, histological observation and push-out test, osseointegration was evaluated. While the rats received thigh-bone removal surgery, another surgery was conducted to remove the tibia metaphysis from the rats of both groups to perform histological observation and micro-CT inspection.Results The trabecular bone of tibial samples was intensive and formed woven mesh structure in the experimental group compared with the control group. In the experimental group, the relative bone volume/tissue volume surrounding the implant, the bone contact ratio, and the maximum push-out force of the implant were 0.35%±0.06%, 67.25%±9.06%, and （70.32±10.91） N, respectively, the corresponding values were 0.11%±0.02%,43.25%±7.01% and （21.65±4.36） N in the control group, and the experimental group increased significantly compared with the control group （P〈0.05）.Conclusion Systemic administration of OT cannot only antagonize the negative effects of osteoporosis but can also promote implant healing and osseointegration of pure titanium implants.