手十二井穴刺络放血后脑卒中好发区组织液流动速率变化规律研究

Changes of rat brain interstitial fluid flow speed after influence of bloodletting puncture of Twelve Jing-Well Points

目的应用MRI示踪技术,定量分析与观察手十二井穴刺络放血后脑卒中好发脑区(丘脑及大脑中动脉供血区)脑细胞外间隙的解剖与组织液流动速率的变化规律,探讨该法对脑卒中神经保护的可能机制。方法成年雄性SD大鼠(32只),随机分为丘脑放血组、丘脑对照组、尾状核放血组、尾状核对照组,每组各8只。丘脑放血组及尾状核放血组接受手十二井穴放血后,将2μL 10 mmol/L GD-DTPA分别导入成年大鼠丘脑区及尾状核区,在导入前后分别进行脑MRI动态扫描(0,15 min、30 min、1 h、2 h、3 h、4 h、5 h、6 h、7 h),利用图像后处理技术,定量分析丘脑区及尾状核区脑组织液引流以及脑细胞周围间隙迂曲度等参数的变化规律。结果丘脑放血组脑组织液流动速率下降,清除时间延长,半衰期达(1.34±0.19)h,长于丘脑区对照组(0.51±0.13)h,差异有统计学意义(P<0.05);局部微观清除率为(7.60±4.18)×10-5/s,明显小于丘脑对照组[(14.40±4.50)×10-5/s],差异有统计学意义(P<0.05)。丘脑放血组丘脑区脑细胞周围间隙迂曲度为(1.29±0.32),与丘脑对照组(1.28±0.17)比较,差异无统计学意义(P>0.05)。尾状核放血组及对照组之间的各项参数未见明显变化,差异无统计学意义(P>0.05)。结论手井穴刺络放血可明显改变丘脑区组织液流速,但对大脑中动脉供血区的脑组织液引流速率没有明显影响。由于刺络放血后丘脑区细胞外间隙的迂曲度没有明显变化,因此,其流速下降应与神经元代谢水平的下调有关,而代谢水平的下调可能是卒中时该法神经保护的机制。

Objective To study the quantitative detection of the changes in the parameter of brain ECS （extracellular space） in the middle cerebral artery （MCA） territory after the influence of blood-letting puncture of Twelve Jing-Well Points using MRI （magnetic resonance imaging） and discuss the therapeutic role of blood-letting for the treatment of stroke.Methods 32 adult male SD rats were randomly divided into blood-letting thalamus group （n=8）,blood-letting caudate nucleus group （n=8）,sham-control thalamus group （n=8） and sham-control caudate nucleus group （n=8）.Extracellular space （ECS） and interstitial fluid （ISF） drainage parameters were measured using Gd-DTPA tracing MRI method.Results The ISF flow speed of blood-letting thalamus group were depressed,the drainage time was lengthen,the Half-life of Gd-DTPA was （1.34±0.19） h,it was longer than that of sham-control thalamus group （0.51±0.13） h,the difference was statistically significant （P ＜ 0.05）; the ISF drainage rates of blood-letting thalamus group [（7.60±4.18）×10-5/s] was less than that of sham-control thalamus group [（14.40±4.50）×10-5/s],the difference was statistically significant （P ＜ 0.05）; the tortuosity of the blood-letting thalamus group was （1.29±0.32）,compared with the sham-control thalamus group （1.28±0.17）,the difference was not statistically significant （P ＞ 0.05）.Each parameter of blood-letting caudate nucleus group and sham-control caudate nucleus group was compared,the difference was not statistically significant （P ＞ 0.05）.Conclusion A significant decrease in ISF drainage rate is revealed after blood-letting puncture of Twelve Jing-Well Points,but most of the middle cerebral artery of the brain tissue fluid drainage rate does not change.No difference is found in the tortuosity of the blood-letting thalamus,so,it is correlated to a lower metabolic rate of local neurons.The down-modulated excitatory state of neurons is assumed to be a beneficial protection for the ischemic neurons using blood-letting puncture of Twelve Jing-Well Points.