绵羊慢性压迫性颈脊髓病动物模型的建立及评估

目的:探讨颈脊髓慢性压迫动物模型的建立方法及可行性评估。方法:将9只绵羊分为对照组(A组)、1个月组(B组)和3个月组(C组)。经颈前路手术将新型注射压迫系统的致压球囊置入C4/5椎间隙并固定,将注射阀埋于颈后皮下。A组术后不注射碘海醇,B、C组术后每周经皮向注射阀注射0.1ml碘海醇,使球囊缓慢膨胀,对颈脊髓产生慢性压迫。每4周于全麻下行颈椎X线、CT和MRI检查。每次注射造影剂后和检查前后用Tarlov评分法对动物进行行为学评价。终止观察时取压迫节段脊髓进行病理观察及电镜观察超微结构变化。应用单因素方差分析评估不同组实验动物行为学的差异,用Pearson相关系数分析各观测参数的相关性。结果:A组各时间点Tarlov评分均为5分。B组及C组每次注射造影剂前后Tarlov评分不变。终止观察时B组实验动物平均椎管侵占率为54.6%,Tarlov评分1只4分,2只5分;C组实验动物平均椎管侵占率67.6%,Tarlov评分1只2分,2只3分。肉眼可见B组受压节段脊髓变扁,C组明显凹陷;病理学检查见B组受压节段脊髓前角内神经元数量减少,胞体周围间隙增大,尼氏体减少,白质轻度脱髓鞘,部分轴突空泡变性;C组白质出现片状脱髓鞘区和空泡变性,灰质内多量神经元变性,可见核固缩、尼氏体减少或消失。电镜下B组神经元胞质内粗面内质网轻度扩张,部分线粒体肿胀,轴突空泡变性,形态不规则,髓鞘松解,部分轴突髓鞘脱失;C组神经元可见胞膜崩解,核固缩,粗面内质网明显扩张,核糖体脱失,线粒体广泛空泡变性,髓鞘崩解,轴突肿胀,基质致密,部分轴突消失。A组未见异常组织学改变。结论:术后实验动物行为学、影像学和组织学检查符合慢性压迫性颈脊髓病特点,新型注射压迫系统可以辅助建立稳定、可靠的慢性颈脊髓压迫动物模型。

Establishment and evaluation of a new experimental animal model of chronic cervical compressive myelopathy

Objective:To explore a new experimental animal model of chronic cervical compressive myelopathy.Method: Nine small-tailed sheep were divided into three groups:control group(A),1-month group(B) and 3-month group(C).The balloon was inserted into the C4/5 intervertebral space by anterior approach,and the syringe valve was fixed subcutaneously.Contrast agent was injected into the valve 0.1ml/week percutaneously.The sheep underent X-ray,CT and MRI under general anesthesia every four weeks.The Tarlov scores were ...