交感神经阻滞对双足直立鼠模型脊柱侧凸发生率和进展的影响

The effect of sympathectomy on the development and progression of scoliosis in bipedal mice model

目的研究交感神经阻滞术对双足直立C57BL／6J小鼠脊柱侧凸发生率和进展的影响。方法选取60只3周龄的C57BL／6J小鼠，手术切除双上肢和尾巴，建立双足直立鼠模型。将实验鼠随机平均分成3组，每组各20只。第一组给予腹腔注射生理盐水5ml／kg（对照组）；第二组给予腹腔注射普萘洛尔（B受体阻滞剂）20mg／kg（普萘洛尔组）；第三组给予腹腔注射硫酸胍乙啶（特异性地破坏交感神经纤维）40mg／kg（胍乙啶组）。建模后第20周时，麻醉下拍摄实验鼠正位X线片，按标准方法测量Cobb角，以Cobb角〉10°作为判断脊柱侧凸的标准，采用行×列X2。检验和单因素方差分析分别比较各组的侧凸发生率和大小。结果对照组共有17只（85．0％）小鼠发生侧凸，普萘洛尔组有11只（55．0％）小鼠发生侧凸，胍乙啶组有10只（50．O％）小鼠发生侧凸；对照组小鼠的脊柱侧凸发生率要高于普萘洛尔组和胍乙啶组，差异有统计学意义（X2=6．172，P=0．046）。对照组平均Cobb角为20°±9°普萘洛尔组平均Cobb角为10°4-7°，胍乙啶组平均Cobb角为12。4-8。；对照组平均Cobb角显著大于普萘洛尔组和胍乙啶组（F=9．545，P〈0．001）；普萘洛尔组与胍乙啶组小鼠平均Cobb角的差异无统计学意义（P〉0．05）。结论交感神经系统可能在双足直立鼠模型脊柱侧凸发生发展的过程中起重要作用。交感神经阻滞并不能显著地降低侧凸的发生率，提示在此动物模型中，直立因素对侧凸的形成也有着重要影响。

Objective To investigate the effect of sympathectomy on the development and progression of seoliosis in bipedal C57BL/6J mice model. Methods Sixty female 3-week-old C57BL/6J mice were selected to establish bipedal seoliotic mice model after amputations of forelimbs and tails. All mice were randomly divided into three groups, 20 mice for each group. Group 1 received daily intraperitoneal injection of 0. 9% saline （5 mg/kg） ; while Group 2 and 3 received sympathectomy by daily intraperitoneal injection of propranolol （20 mg/kg） and guanethidine sulfate （40 mg/kg） , respectively. Posteroanterior X-rays were obtained at 20th week. Curves were measured using Cobb method and scoliosis was defined as a Cobb angle of 〉 10~. Incidence of scoliosis and severity of curves were compared among groups using Chi-square test and One-way analysis of variance, respectively. Results There were 17 （ 85.0% ） mice presented scoliosis in Group 1 ; whereas 11 （55.0%） and 10 （50.0%） mice presented scoliosis in Group 2 and 3, respectively. The incidence of scoliosis was found to be higher in Group 1, and the difference was statistically significant （ X2 = 6. 172,P = 0. 046）. As for curve magnitudes, the mean Cobb angle was 20°± 9° in Group 1, 10° ±7° in Group 2, and 12°±8°in Group 3. The mean Cobb angle of Group 1 was significantly greater than those of Group 2 and 3 （ F = 9. 545, P 〈 0. 001 ） , but there was no significant difference in mean Cobb angle between Group 2 and 3. Conclusions Sympathetic nervous system may be involved in the development and progression of scoliosis in bipedal C57BL/6J mice model. Sympathectomy do not seem to dramatically decrease the incidence of scoliosis, probably due to that bipedalism itself mayalso be a cause of scoliosis in this animal model.