颈椎旋转手法对兔颈动脉粥样硬化血管拉伸力学特性的影响

Effects of cervical rotatory manipulation on tensile mechanical properties of atherosclerotic carotid artery in rabbits

目的研究颈椎旋转手法对兔颈动脉粥样硬化血管拉伸力学特性的影响,为颈椎旋转手法的安全性提供依据。方法 20只雄性新西兰兔随机分为2组,每组各10只,均饲高脂饮食12周建立动脉粥样硬化动物模型。12周后对实验组兔行颈椎旋转手法,每日左、右各旋转1次,共4周;对照组不作手法处理。手法结束后处死兔,取双侧颈动脉,利用生物组织材料力学试验机测定颈动脉拉伸最大载荷、最大形变、平均载荷、弹性模量和断裂延伸率等指标以及输出应力—应变曲线。结果实验组颈动脉拉伸最大载荷(1.36±0.35)N,最大形变(6.84±2.08)mm,平均载荷(0.44±0.30)N,弹性模量(4.30±2.66)MPa,断裂延伸率(83.08±51.32)%;对照组颈动脉拉伸最大载荷(2.92±0.65)N,最大形变(9.23±2.62)mm,平均载荷(1.17±0.63)N,弹性模量(3.71±0.60)MPa,断裂延伸率(154.19±34.32)%。其中,实验组颈动脉拉伸的最大载荷、平均载荷和断裂延伸率明显小于对照组(P<0.05);而最大形变以及弹性模量在两组中差异无统计学意义(P>0.05)。结论经颈椎旋转手法后,颈动脉粥样硬化血管的拉伸力学特性下降,应注意颈椎旋转手法操作的力度和幅度,以免伤及颈动脉。

Objective To observe the effect of cervical rotatory manipulation on tensile mechanical properties of atherosclerotic carotid artery in rabbits,so as to provide safety references for such manipulation.Methods Twenty male New Zealand rabbits were randomly divided into control group （n =10） and experimental group （n =10）,then all fed with high-cholesterol diet for 12 weeks.The rabbits in experimental group were then applied with cervical rotatory manipulation （rotating on each side once a day during a total of 4 weeks）,while no manipulation for rabbits in control group.The bilateral carotid arteries were obtained after all the rabbits were executed,and measured for the maximum load,the maximum displacement,the average load,the elastic modulus,elongation at break and stress-strain by the material testing machine.Results The maximum tension,the maximum displacement,the average tension,the elastic modulus and elongation at break in experimental group were （1.36 ± 0.35） N,（6.84 ± 2.08） mm,（0.44 ± 0.30） N,（4.30 ± 2.66） MPa and （83.08 ± 51.32） ％,respectively,while the corresponding data in control group were （2.92 ±0.65） N,（9.23 ±2.62） mm,（1.17 ±0.63） N,（3.71 ± 0.60） MPa and （154.19 ± 34.32） ％.The maximum load,the average load and elongation at break in experimental group were obviously smaller than those in control group （P ＜ 0.05）,while no statistical differences in the maximum displacements and elastic modulus between two groups were found （P ＞ 0.05）.Conclusions The tensile mechanical properties of atherosclerotic carotid artery after cervical rotatory manipulation were declined; thus,intensity and magnitude of cervical rotatory manipulation should be proper so as to avoid harm to carotid artery.