应用同步辐射血管造影观察褪黑素对大鼠蛛网膜下腔出血致血管痉挛的影响

目的探讨褪黑素对蛛网膜下腔出血（SAH）所致脑血管痉挛的影响。方法将60只SD大鼠随机分为正常对照组、SAH组、溶剂组及褪黑素组,每组15只。采用视交叉上池注射自体血的方法制作大鼠SAH模型。褪黑素组大鼠于模型制备后立即经腹腔注射褪黑素1次（15 mg/kg）,24 h再给同等量药物1次。对溶剂组以无水乙醇（10%,15 ml/kg）替代褪黑素,其他与褪黑素组相同。对正常对照组不给予任何处理。于术后第2天行神经行为学评分检查;第3天行同步辐射血管造影（SRA）观察活体大鼠颅内血管管径变化情况;病理学检查（HE染色）观察大脑前动脉（ACA）直径的改变。结果①褪黑素组神经行为学评分为（15.2±2.9）分,高于SAH组的（11.8±2.3）分和溶剂组的（11.6±3.4）分,均P〈0.05。但均低于正常对照组的18分,P〈0.05。②SRA法测量ACA直径,褪黑素组为（304±60）μm,与SAH组的（215±36）μm和溶剂组的（211±40）μm比较,差异均有统计学意义,P〈0.05,但仍低于正常对照组的（349±26）μm,P〈0.05。③病理学检查测量ACA管径,褪黑素组为（185±34）μm,SAH组为（101±20）μm,溶剂组为（103±19）μm,差异有统计学意义,P〈0.05;均低于正常对照组的（216±10）μm,P〈0.05。结论褪黑素可明显改善SAH所致的脑血管痉挛。SRA法是一种能够直接评估活体大鼠SAH所致脑血管痉挛的新技术。

Observation of the effect of melatonin on subarachnoid hemorrhage-induced cerebral vasospasm in rats using synchrotron radiation angiography

objective To investigate the effect of melatonin on subarachnoid hemorrhage(SAH)-induced cerebral vasospasm.Methods Sixty SD rats were randomly allocated into a normal control group,a SAH group,a solvent group,and a melatonin group.A rat model of SAH was inducted by injecting autologous blood into prechiasmatic cistern.The melatonin was injected intraperitoneally once(15 mg/kg) in the rats of melatonin group immediately after modeling,and the same amount of drug was given again at 24 hours.Melatonin was alternated by the equal volume of 10% ethanol(15 mL/kg) in the solvent group,the others management were the same with the melatonin group.The normal control group did not give any treatment.Neurological score was assessed 2 days after surgery;synchrotron radiation angiography(SRA) and pathological examination(HE staining) were used to observe in vivo rat intracranial vascular changes and the diameter of anterior cerebral artery(ACA) at day 3.Results ① The neurobehavioral score in the melatonin group was 15.3±2.9,it was higher than 11.8±2.3 in the SAH group and 11.6±3.4 in the solvent group(all P<0.05),however,they were all lower than 18 in the normal control group(P<0.05).② The ACA diameter was measured by SRA technique,the melatonin group was 304±60 μm.There was significant difference as compared to the 215±36 μm in the SAH group and 211±40 μm in the solvent group(P<0.05),however,they still lower than 349±26 μm in the normal control group(P<0.05).③ Pathology measurements of the ACA diameter in the melatonin group was 185±34 μm,in the SAH group was 101±20 μm,and in the solvent group was 103±19 μm.There were significant differences(P<0.05);However they were all lower than 216±10 μm in the normal control group(P<0.05).Conclusion Melatonin may significantly alleviate SAH-induced cerebral vasospasm.SRA is a novel technique that may directly evaluate the SAH-induced cerebral vasospasm of rats in vivo.