动态负荷下前列腺素E_1对受压马尾神经血流量变化的影响

目的 :研究动态负荷下前列腺素E1对受压马尾神经血流量变化的影响。方法 :分 4组 ,每组 6只。除对照组 ,其他 3个实验组制成 3 0 %的双节段狭窄。施加压迫 2h后 ,3个实验组分别施加动态负荷 (高频率刺激和 (或 )压迫追加 ) 6min。实验 3组在施加动态负荷前给予前列腺素E1。结果 :对照组马尾神经血流量在最初 2h无显著变化 ,施加高频率刺激时显著升高至 ( 186.4 -3 1.5 ) % (P <0 .0 5 )。施加动态负荷时 ,实验 1组血流无显著变化 (P >0 .0 5 ) ;实验 2组降至 ( 65 .3 -10 .7) % (P <0 .0 5 ) ;实验 3组为 ( 118.5 -2 3 .6) % ,与实验 2组有显著差异 (P <0 .0 5 )。结论 :双节段压迫会限制马尾神经血流量增加而造成相对缺血。若神经电活动与压迫程度同时增加 ,血流量显著降低 ,造成绝对缺血。前列腺素E1可以在动态负荷下维持马尾神经血流量 ,避免其进入绝对缺血状态。

Experimental Study of Effect of Prostaglandin E_1 on Changes of Blood Flow of Compressed Cauda Equina Under Dynamic Burden

Objective: To reveal the effect of prostaglandin E 1 (PGE 1) on the change of blood flow of compressed cauda equina under dynamic burdens. Methods: Twenty four SD rats were divided into 4 groups, 6 in each. One group had laminectomy of the fifth lumbar vertebra only served as control. In the other 3 experimental groups, silicon sheets were inserted into the spinal canal of L 4 and L 6 after L 5 lumbar vertebra being laminectomized to cause double level compression of cauda equina by 30% stenosis. Two hours after onset of compression, high frequency stimulation (HFS) was introduced to group 1 for 6 minutes. Both HFS and additional compression increase were introduced to group 2 for 6 minutes. PGE 1 was administered to group 3 before the introduction of HFS and additional compression increase. Results: In the first two hours, there was no significant change of cauda equina blood flow in the control group. During HFS, the average blood flow increased significantly to (186.4 -31.5)% of initial value ( P < 0.05 ). Blood flow of group 1 was (111.6 -17.6)% of initial value after introduction of HFS, no significant change compared to the value before HFS( P >0.05). Blood flow of group 2 decreased to (65.3 -10.7)% of initial value ( P < 0.05 ), while the value remained at (118.5 -23.6)% in the group 3. The difference was significant between the last two groups ( P <0.005). Conclusions: It shows that increase of impulse transmission might increase blood flow of normal cauda equina, while double level compression of cauda equina might limit the increase of blood flow, which might cause relative ischemia. If there is additional increase of compression during impulse transmission increase, not only the blood flow could not remain at normal level, but also would decrease significantly, which might cause absolute ischemia of cauda equina. PGE 1 might maintain the blood flow under dynamic burden and prevent compressed cauda equina going into the state of absolute ischemia.