麻黄碱在大鼠脑缺血-再灌注损伤中的意义

Role of ephedrine against cerebral ischemia-reperfusion injury in rats

目的:探讨麻黄碱对缺血-再灌注损伤大鼠的神经保护机制.方法:体内部分:正常大鼠,分为4组,每组6只,分别腹腔注射不同剂量(2,4,8mg/kg)麻黄碱和等体积生理盐水,每3日1次,共4次,应用放射免疫组织化学方法检测大鼠血浆中血栓素B2和6酮前列腺素F1α浓度,并且计算两者比值.MCAO模型大鼠分组、给药剂量及方法同于正常组.体外部分:培养大鼠脑皮质微血管内皮细胞,分为麻黄碱给药组(培养基麻黄碱的浓度分别为2,4,8mg/L)和对照组(培养基无麻黄碱)培养2h后检测6酮前列腺素F1α浓度.结果:体内部分:①正常大鼠:麻黄碱8mg/kg组TXB2,6-Keto-PGF1α和T/P低于正常对照组(P<0.05).②MCAO模型大鼠:各给药组TXB2和T/P均低于对照组(P<0.05).③MCAO模型对照组TXB2,6-Keto-PGF1α和T/P高于正常对照组(P<0.05).体外试验:麻黄碱各浓度组6-Keto-PGF1α与对照组的差别无统计学意义(P>0.05).结论:麻黄碱对大鼠血浆TXA2-PGI2平衡的影响可能与其对缺血-再灌注损伤大鼠的神经保护性作用有关.

AIM： To investigate the protective effects of ephed- rine on the rats with cerebral ischemia-reperfusion injury. METHODS： In vivo： Normal rats were randomly divided into 4 groups and injected respectively with ephedrine （2, 4, 8 mg/kg） and equal volume normal saline, once every 3 d, totally for 4 times. The plasma concentrations of thromboxane B2 （ TXB： ） and 6-keto-PGF1α were detected by radio-immunohistochemistry. The ratio of TXB2 to 6-keto-PGF1α （T/P） was calculated. The subgrouping, administrated doses and manner in middle cerbral artery occlusion （MCAO） group are same as the normal control group; In vitro： The brain microvascular endothelial cells were cultured and divided into 3 ephedrine groups （2, 4 and 8 mg/L） and 1 control group （no ephedrine）. The plasma concentration of 6- keto-PGF1α was detected after 2 h. RESULTS： In vivo： In the normal rats, T/P, the plasma concentrations of TXB2 and 6-Keto- PGF1α in the groups treated with 8mg/kg ephedrine were significandy lower than those in the control group （ P 〈 0.05 ）. In the MCAO rats, compared to the control group, the TXB2 concentration and T/P in all treated groups were significantly lower （P 〈 0.05） ; In vitro ： The concentration of 6-Keto-PGF1α in each group was not different statistically （P 〉 0.05）. CONCLUSION： The protective effects of ephedrine on the MCAO rats may be related to balancing the ratio of TXA2/PG1α.