毕格犬和杂种犬脑血管及脑组织的对照研究

The cerebrovascular structure and brain tissue volume:a comparative study between beagle dogs and mongrel dogs

目的用血管造影以及MR扫描观察毕格犬和杂种犬头颈部血管、脑组织的结构,分析比较两组犬的脑血管和脑体积的差异。方法实验采用20条毕格犬和20条杂种犬,全麻下插管分别至犬的主动脉弓、双侧颈外动脉(ECA)、颌内动脉、颈内动脉(ICA)、椎动脉进行血管造影观察其血管解剖的情况,并分别测量每条犬左侧ICA颈段、大脑中动脉、大脑嘴侧动脉、ICA-ECA吻合支以及基底动脉相近部位的血管直径;采用MR的T2加权冠状位测量各条犬的脑组织体积。分析比较犬的体重和各血管直径以及脑体积的相关性,比较两组犬的血管直径、脑体积的差异和ICA优势的情况。结果两组犬的头颈部血管和脑组织结构未见明显变异,杂种犬组中1条犬ICA颈段异常狭窄未纳入统计分析。20条毕格犬和19条杂种犬的平均体重分别为(12.81±1.29)kg和(12.85±1.12)kg;两组犬左侧ICA颈段、大脑中动脉、大脑嘴侧动脉、ICA-ECA吻合支以及基底动脉相似部位的血管直径分别为:毕格犬(1.26±0.07)mm、(0.90±0.05)mm、(0.58±0.07)mm、(0.55±0.07mm)、(0.95±0.06)mm,杂种犬(1.27±0.07)mm、(0.92±0.05)mm、(0.59±0.06)mm、(0.67±0.07)mm、(0.94±0.05)mm;脑体积分别为(76 232.33±5 018.51)mm3和(71 863.96±4 624.87)mm3。统计分析显示两组犬的体重与血管直径、脑体积无明显的相关性;杂种犬组ICA-ECA吻合支的直径大于毕格犬组(t=5.5798,P=0.000);毕格犬组的脑组织体积略大于杂种犬组(t=-2.8225,P=0.0076)。结论犬的脑体积和血管直径变异较小,在一定范围内与体重没有明显的相关性;毕格犬的颅内外血管吻合相对少,脑组织体积相对大,更加适合建立脑梗死的动物模型。

Objective To compare the differences of cerebrovascular structure and brain tissue volume between beagle and mongrel dogs by using angiography and MR scanning.Methods A total of 40 dogs,including 20 beagle dogs（beagle group） and 20 mongrel dogs（mongrel group）,were enrolled in this study.Under general anesthesia,all dogs were examined with cerebral angiography and MR scanning.The cerebrovascular structure was evaluated with angiography via selective catheterization of aortic arch,bilateral external cerebral arteries（ECA）,maxillary arteries,internal cerebral arteries（ICA） and vertebral arteries separately.The diameters of the ICA,middle cerebral artery（MCA）,rostral cerebral artery（RCA）,the anastomosis channel between ICA and ECA,and basilar artery（BA） were measured at the similar point of each dog.Meanwhile the volumes of the brain tissue were calculated in coronal T2 view of MR scanning.The statistical analysis was performed among the weight of dogs,the diameter of arteries and the volume of brain tissue.The differences in the diameters and brain tissue volume were compared between the two groups.Results No obvious variations in the cerebrovascular structure and brain tissue volume were found in these dogs.One mongrel dog was excluded from this study because of the severe stenosis of ICA.The mean weight of 20 beagle dogs and 19 mongrel dogs was（12.81 ± 1.29） kg and（12.85 ± 1.12） kg,respectively.The diameters of the ICA,MCA,RCA,the anastomosis channel between ICA and ECA and BA in beagle group were（1.26 ± 0.07） mm,（0.90 ± 0.05） mm,（0.58 ± 0.07） mm,（0.55 ± 0.07） mm and（0.95 ± 0.06） mm,respectively.These parameters in mongrel group were（1.27 ± 0.07） mm,（0.92 ± 0.05） mm,（0.59 ± 0.06） mm,（0.67 ± 0.07） mm and（0.94 ± 0.05） mm,respectively.The volume of brain in two groups was（76 232.33 ± 5 018.51） mm3 and（71 863.96 ± 4 624.87） mm3,respectively.There were no obvious correlation among the body weight,the cerebrovascular diameters and brain volume.The diameter of the anastomosis channel between ICA and ECA was significantly larger in mongrel dogs than that in beagle dogs（t = 5.5798,P = 0.000）,whereas the brain volume of beagle dogs was bigger than that of mongrel dogs（t =-2.8225,P = 0.0076）.Conclusion There are few variations of cerebrovascular structures and brain tissue volume in dogs,and no statistically significant correlations exist among the body weight,the vascular diameters and the brain volume in dogs.Compared with mongrel dogs,beagle dogs have bigger brain tissue volume and smaller anastomosis channel between ICA and ECA.Therefore,beagle dogs are more suitable for experimental study of ischemic stroke.