补阳还五汤改善脑缺血大鼠血流灌注的多模态磁共振成像研究

Multimodal magnetic resonance imaging study on Buyang Huanwu Decoction improving cerebral blood flow in cerebral ischemic rats

目的利用多模态磁共振成像(magnetic resonance imaging,MRI)技术纵向观察补阳还五汤对脑缺血大鼠侧支循环及血流灌注的影响。方法采用线栓法建立永久性中动脉栓塞致脑缺血大鼠模型。将造模成功的24只大鼠随机分为模型组、补阳还五汤高剂量组(16.6 g/kg)、补阳还五汤低剂量组(8.3 g/kg),每组8只,以及假手术组(8只),共分4组。各给药组大鼠在造模后24小时灌胃给药,连续给药15天。假手术组和模型组大鼠给予等量生理盐水。分别在给药后第7天和15天进行多模态MRI扫描。利用T2加权成像检测脑梗死体积,磁共振血管成像检测颅内动脉信号,动脉自旋标记检测缺血边缘血流灌注。结果与假手术组大鼠比较,缺血7天和15天后,模型组大鼠缺血侧前动脉(anterior cerebral artery,ACA)、颈内动脉(internal carotid artery,ICA)、后动脉(posterior cerebral artery,PCA)血管信号强度显著降低(P<0.05,P<0.001),基底动脉(basilar artery,BA)信号强度显著升高(P<0.001),缺血边缘血流灌注明显降低(P<0.001)。与模型组比较,补阳还五汤高、低剂量治疗均可明显减少缺血7天后脑梗死体积(P<0.05),降低缺血7天和15天BA信号强度(P<0.05,P<0.01),并升高缺血15天后缺血边缘的血流灌注(P<0.001)。此外,补阳还五汤高剂量治疗还可以降低缺血15天后脑梗死体积(P<0.01),并升高ACA及ICA信号强度(P<0.05);补阳还五汤低剂量还可以升高缺血7天后缺血边缘的血流灌注(P<0.05)。结论补阳还五汤可促进颅内关键动脉侧支循环建立,改善脑血流灌注,降低脑梗死体积,保护脑组织。

Objective This study aimed to observe the effects of Buyang Huanwu Decoction(BHD)on collateral circulation and cerebral blood flow in rats with cerebral ischemia using multimodal magnetic resonance imaging(MRI)techniques.Methods The permanent middle cerebral artery occlusion(MCAO)model was established using the suture method in rats.A total of 24 rats were randomly divided into the sham group,model group,BHD high-dose group(16.6 g/kg),and BHD low-dose group(8.3 g/kg),8 rats per group.Rats in the treatment groups received oral administration of BHD or an equal volume of saline for 15 consecutive days,starting 24 hours after the surgery.Multimodal MRI was performed on the 7 th and 15 th day following ischemia onset.T2-weighted imaging was used to measure the infarct volume.Magnetic resonance angiography was performed to evaluate the signal intensities of the anterior cerebral artery(ACA),internal carotid artery(ICA),posterior cerebral artery(PCA),and basilar artery(BA).Arterial spin labeling was applied to assess cerebral blood flow at the periinfarct area.Results Compared with the sham group,the model group showed a significant decrease in signal intensity of the ACA,ICA,and PCA(P<0.05,P<0.001)and a significant increase in signal intensity of the BA(P<0.001)on days 7 and 15 after ischemia.Additionally,there was a significant reduction in cerebral blood flow at the periinfarct area(P<0.001).Compared with the model group,both high-dose(16.6 g/kg)and low-dose(8.3 g/kg)BHD treatments significantly reduced the infarct volume on day 7 after ischemia(P<0.05),decreased the signal intensity of the BA on days 7 and 15(P<0.05,P<0.01),and increased the cerebral blood flow at the periinfarct area on day 15(P<0.001).Furthermore,the high-dose BHD treatment also reduced the infarct volume(P<0.01)and increased the signal intensity of the ACA and ICA(P<0.05)on day 15 after ischemia,while the low-dose BHD treatment increased the cerebral blood flow at the ischemic border on day 7 following ischemia(P<0.05).Conclusion BHD could promote the establishment of collateral circulation in the key intracranial arteries,improve cerebral blood flow,and reduce infarct volume,thereby protecting the brain.