L-精氨酸枕大池注射对兔脑血管痉挛的影响及作用机制(英文)

Effect of continuous intracisternal L arginine infusion on rabbit experiment cerebral vasospasm and mechanism

目的:研究L-精氨酸枕大池注射对兔蛛网膜下腔出血后血管痉挛的影响及作用机制。方法:采用双侧颈动脉结扎及枕大池二次注血法制造兔蛛网膜下腔出血模型。在蛛网膜下腔出血后第4天,以比色法测定血清及脑脊液中一氧化氮及脑组织的浓度。光镜下测定基底动脉的动脉壁厚度和基底动脉的内径,以其比值作为脑血管痉挛的指标。治疗组分为300μmol/L及500μmol/L组,在蛛网膜下腔出血后第4天,枕大池持续微泵滴注L-精氨酸,在滴注后再分别研究上述指标。结果:蛛网膜下腔出血后第4天,基底动脉的动脉壁厚度和内径的比值(0.085±0.007)明显升高(t=20.26,P<0.05);血清一氧化氮犤(24.34±7.36)μmol/L,t=6.72,P<0.05犦及脑脊液中一氧化氮犤(10.68±3.43)μmol/L,t=4.25,P<0.05犦及脑组织NOS犤(0.007±0.001)nmol/(s·g),t=6.14,P<0.05犦.的浓度降低。在L-精氨酸滴注后,脑血管痉挛缓解。血清一氧化氮犤(37.38±6.42)μmol/L,t=3.27,P<0.05犦、脑脊液中一氧化氮犤(14.16±3.36)μmol/L,t=1.98,P<0.05犦脑组织一氧化氮合酶(nitricoxygenase,NOS)犤(0.011±0.002)nmol/(s·g),t=3.10,P<0.05犦的浓度较对照组明显升高。结论:L-精氨酸枕大池注射对兔蛛网膜下腔出血后的血管痉挛具有治疗作用。

AIM:To investigate the effect and mechanism of continuous intracisternal infusion of L arginine on cerebral vasospasm following rabbit subarachnoid hemorrhage(SAH). METHODS:The SAH model was set up by blood given twice percutaneously into the cistern after occlusion of bilateral carotid artery in rabbits.At day 4 after SAH,Nitric oxide (NO) concentrations in serum and cerebrospinal fluid(CSF) were detected by chromometry.Nitric oxide synthase(NOS)activity in cerebral tissue was also measured. The wall thickness to its inner diameter ratio was calculated on basilar artery as an indictor of cerebral vasospasm under optical microscope.The therapeutic group was divided into 300 μmol group and 500 μmol group.After continuous intracisternal L arginine infusion,the data mentioned above were detected again at day 4. RESULTS:At day 4 following SAH,the concentrations of NO in serum [(24.34±7.36)μmol/L,t=6.72,P< 0.05] and CSF[(10.68±3.43) μmol/L,t=4.25,P< 0.05] significantly decreased as well as NOS activity in cerebral tissue[(0.007±0.001) nmol/ (s·g),t=6.14,P< 0.05].The wall thickness to its inner diameter ratio was elevated in the therapeutic group(0.085±0.007) as compared with the control group(t=20.26,P< 0.05). After infusion of L Arginine,the vasospasm was of remission,and the concentrations of NO in serum[(37.38±6.42) μmol/L,t=3.27,P< 0.05] and CSF[(14.16±3.36) μmol/L,t=1.98,P< 0.05] as well as NOS activity in cerebral tissue[(0.011±0.002) nmol/(s·g),t=3.10,P< 0.05] were significantly elevated as compared with those in the control group. CONCLUSION:L arginine treatment may be useful for remission of vasospasm.The therapeutic effect of L arginine might be produced via NO and NOS system.