艾灸对缺氧缺血性脑损伤新生小鼠的治疗作用*

目的: 探讨艾灸对缺氧缺血性脑损伤新生小鼠行为学表现、脑组织形态结构的影响及作用机制。方法: 将106只出生7 d小鼠随机分为三组:假手术组(23只)、模型组(46只)和艾灸组(37只)。采用左侧颈总动脉结扎后再置于37℃密闭舱内进行低氧处理(氧气浓度为8%,100 min),制备新生儿缺氧缺血性脑病动物模型。艾灸组同模型组,并于造模后2 h开始艾灸“大椎”进行治疗,以后每日1次,每次35 min,连续治疗4 d。采用行为学测试评价小鼠的行为学表现;HE染色观察小鼠脑组织形态结构;Western blot技术检测小鼠脑组织超氧化物歧化酶2(SOD2)蛋白表达;比色法测定小鼠脑组织丙二醛(MDA)含量。结果: 假手术组小鼠行为表现正常,脑组织细胞排列致密整齐,脑组织SOD2蛋白表达量和MDA含量正常。与假手术组相比,模型组小鼠翻正反射、趋地反射、悬崖躲避试验时间延长(P＜0.05),抓力试验时间缩短(P＜0.05);脑组织细胞大量坏死脱落;脑组织SOD2蛋白表达量明显减少(P＜0.05)、MDA含量增加。与模型组相比,艾灸组小鼠翻正反射、趋地反射、悬崖躲避试验时间缩短(P＜0.05),抓力试验时间增长(P＜0.05);脑组织细胞排列较致密、整齐;脑组织SOD2蛋白表达量增多(P＜0.05)、MDA含量降低(P＜0.05)。结论: 艾灸能减轻缺氧缺血性脑病新生小鼠脑损伤、改善行为学表现,这可能与其增加脑组织SOD2蛋白的表达、降低MDA含量,从而提高抗氧化应激能力有关。

Therapeutic effects of moxibustion on neonatal mice with hypoxia-ischemia brain injury

Objective: To investigate the effects of moxibustion on the behavioral performance, brain morphological structure of mice with hypoxia-ischemia brain injury and to explore its mechanisms. Methods: One hundred and six ICR mice were randomly divided into three groups, sham group (n=23), model group (n=46) and moxibustion-treated group (n=37). Neonatal hypoxic-ischemia brain injury was induced by ligation of common carotid artery followed by hypoxia (8% oxygen, 100 min), and pups in the moxibustion-treated group were administered suspended moxibustion on the Dazhui points (GV14) at a height of approximately 2 cm over a hairless area of the skin once a day for 4 days (i.e. at 2, 24, 48 and 72 hours after hypoxia-ischemia procedure). Behavioral tests were used to evaluate behavioral performance. HE staining was used to observe brain morphological structure. Western blot was used to detect the expression of SOD2 protein, and spectrophotometry was used to determine the content of MDA in the ipsilateral brain. Results: Mouse pups in sham group showed that the behavioral performance was normal, the brain tissue cells were densely and neatly arranged, the expression of SOD2 and the level of MDA in the brain tissues were normal. Compared with sham group, mouse pups in the HI model group exhibited a significant longer latency to complete the righting reflex, geotaxis reflex, cliff avoidance (P＜0.05) and a marked shorter latency to complete the grip test (P＜0.05); and the HI model group had dramatic brain morphological changes showing missing regions, decreased expression of SOD2 protein (P＜0.05) and increased level of MDA in the brain. Compared with HI model group, mouse pups in the moxibustion-treated group exhibited a significant shorter latency to complete the righting reflex, geotaxis reflex, cliff avoidance test (P＜0.05) and a marked longer latency to complete the grip test (P＜0.05); and the moxibustion-treated group had less brain morphological changes, increased expression of SOD2 protein (P＜0.05) and decreased level of MDA in the brain (P＜0.05) . Conclusion: Moxibustion could improve behavioral performance and attenuate hypoxia-ischemia brain injury, which might be related to increasing the expression of SOD2 protein and decreasing the content of MDA, thus enhancing the anti-oxidative ability.