上胸段硬脊膜外腔注射罗哌卡因纳米粒对兔脑血管痉挛后血管内皮细胞凋亡的影响

Effect of ropivacaine polylactic-co-glycolic acid nanoparticle injection in upper thoracic epidural space on vascular endothelial apoptosis

目的探讨兔上胸段硬脊膜外腔注射罗哌卡因乳酸羟基乙酸共聚物纳米粒对兔脑血管痉挛(CVS)后血管内皮细胞凋亡的影响。方法将上胸段硬脊膜外腔置管成功的新西兰兔30只随机分为假手术组、对照组、空白纳米粒组、纳米粒载药组和罗哌卡因组,每组6只。采用"枕大池二次注血法"制作蛛网膜下腔出血(SAH)模型。在枕大池注射前和枕大池注血或注射0.9%氯化钠溶液后1、3、7d时,应用经颅多普勒超声检测基底动脉的平均血流速度(Vm)和收缩期峰值血流速度(Vp)。在枕大池注血或注射0.9%氯化钠溶液后7d于光学显微镜下观察基底动脉的形态并测量其管腔直径。采用TUNEL法检测基底动脉内皮细胞凋亡情况。结果假手术组脑组织无明显水肿,可见清晰的基底动脉,无血凝块;对照组和空白纳米粒组脑组织肿胀明显,脑底面见明显的血凝块,其中基底动脉、Willis环周围最多,脑底池呈暗红色;与对照组和空白纳米粒组比较,纳米粒载药组和罗哌卡因组脑组织肿胀均有所减轻。对照组、空白纳米粒组、纳米粒载药组和罗哌卡因组的基底动脉管腔直径均显著小于假手术组(P值均<0.01),管壁内膜层荧光强度值和内皮细胞凋亡指数均显著大于假手术组(P值均<0.01);纳米粒载药组和罗哌卡因组的基底动脉管腔直径均显著大于对照组和空白纳米粒组(P值均<0.01),管壁内膜层荧光强度值和内皮细胞凋亡指数均显著小于对照组和空白纳米粒组(P值均<0.01)。对照组、空白纳米粒组、纳米粒载药组和罗哌卡因组注射后1、3d的基底动脉Vm和Vp均显著快于假手术组同时间(P值均<0.05),对照组、空白纳米粒组注射后7d的基底动脉Vm和Vp均显著快于假手术组同时间(P值均<0.05);纳米粒载药组和罗哌卡因组注射后1、3、7d的基底动脉Vm和注射后3、7d的基底动脉Vp均显著慢于对照组和空白纳米组同时间(P值均<0.01)。结论兔上胸段硬脊膜外腔注射罗哌卡因乳酸羟基乙酸共聚物纳米粒能减少SAH后CVS的血管内皮细胞凋亡。

Objective To explore the influence of ropivacaine polylactic-co-glycolic acid nanoparticle injected in the upper thoracic epidural space on vascular endothelial apoptosis after cerebral vasospasm of rabbits. Methods The upper thoracic epidural catheter was successfully constructed in 30 New Zealand rabbits. Then they were equally assigned to five groups （n=6）. sham-operated group, control group, placebo nanoparticle group, ropivacaine-loaded nanoparticle group, and pump ropivacaine group. Subarachnoid hemorrhage （SAH） was established by two injection of autoblood into the cistern magna. Transcranial doppler ultrasonography （TCD） wasused to inspect the basilar artery mean flow velocity （Vm） and peak systolic blood flow velocity （Vp） before prechiasmatic injection, and 1, 3, 7 days after prechiasmatic injection. Histology was conducted on basilar artery onthe 7th day after the injection, then tube＇s diameter was measured. Terminal deoxynucleotidyl transferase （TdT）-dUTP nick-end labeling （TUNEL） was used to observe the apoptosis of vascular endothelial cells. Results There was no obvious edema on brain tissue in sham-operated group, and basilar artery was clearly visible and no blood clots were found. On the contrary, there were obvious edema on tissue of brain in control and placebo nanoparticle groups, blood clots were found on cerebral underside, especially in basal artery and Willis ring, and cerebral cisterna was dark red. However, cerebral swelling alleviated in ropivacaine-loaded nanoparticle group and pump ropivacaine group when compared with control group and placebo nanoparticle group. Oompared with sham-operated group, basal arterial diameter was significantly decreased, fluorescence intensity of wall lining layer and endothelial cell apoptosis were significantly increased in the other four groups （all P〈0.01 ）. Compared to control and placebo nanoparticle group, basal arterial diameter was significantly increased in ropivacaine-loaded nanoparticle and pump ropivacaine group （all P〈0.01）. nevertheless, fluorescence intensity of wall lining layer and endothelial cell apoptosis were significantly decreased （all P〈0.01）. Vm and Vp in sham-operated group were significantly slower than those in the other four groups on the first and third days after injection （all P〈 0.05） ; meanwhile, Vm and Vp in sham-operated group were significantly slower than those in control and placebo nanoparticle groups on the seventh day after injection （all P〈0.05）. Vm on the first, third and seventh days after injection and the Vp on the third and seventh days in ropivacaine-loaded nanoparticle and pump ropivacaine group were significantly slower than those in control and placebo nanoparticle groups （all P〈 0.01）. Conclusion Ropivacaine polylactic-co-glycolic acid nanoparticle injected in upper thoracic epidural space can reduce apoptosis of vascular endothelial cells on cerebral vasospasm after subarachnoid hemorrhage in rabbits.