高压氧治疗时机对家兔实验性局部脑缺血治疗效果的影响及微透析监测研究

目的 观察高压氧(HBO)治疗时机对家兔实验性局部脑缺血治疗效果的影响.方法 75只家兔按随机数字表法平均分为3组,每组25只,即大脑巾动脉闭塞(MCAO)组:右侧大脑中动脉阻断.不行HBO治疗;MCAo+HBO组:右侧大脑巾动脉阻断后即予HBO治疗;MCAO+DHBO组:右侧大脑巾动脉阻断7d后行HBO治疗.动物放入HBO舱(100%O2,250 kPa,1 h/d)行HBO治疗30 d.MCAO后第1天、第3天、第10天、第30天观察各组动物的行为学变化、脑梗死体积,并采用微透析技术分析家兔缺血脑组织细胞间液中的葡萄糖、乳酸、丙酮酸、乳酸/丙酮酸比值以及谷氨酸水平的变化.结果 缺血后MCAO+HBO组行为学评分较其他组低;第3天至第30天,MCAO+HBO组脑梗死体积低于其他两组,差异有统计学意义(P<0.05).微透析分析能量代谢指标中乳酸丙酮酸比值变化最为明显.其中缺血后1 d和3 d右侧脑组织间液中MCAO+HBO组较其他两组降低,差异有统计学意义(P<0.05).缺血后家兔脑组织间液中谷氨酸浓度升高,3d时逐渐下降,缺血后1 d和3d右侧腩组织间液中MCAO+HBO组较其他两组降低,差异有统计学意义(P<0.05).结论 HBO治疗能通过改善神经组织的能量代谢,减轻兴奋性氨基酸毒性作用,改善缺血缺氧对神经的损害;而HBO治疗脑梗死应尽早进行.

Efficacy of different hyperbaric oxygen treatment time for focal cerebral infarction in rabbits and microdialysis study

Objective To observe the therapeutic efficacy of hyperbaric oxygen (HBO) for focal cerebral infraction influenced by the treatment time after permanent middle cerebral artery occlusion (MCAO) in rabbits. Methods Seventy-five male rabbits were randomly divided into simple MCAO group (n=25), MCAO+HBO group (100% O2, 250 kPa, 1 h/d, from 1 d after MCAO, n=25) and MCAO+DHBO group (100% O2, 250 kPa, 1 h/d, from 7 d after MCAO, n=25). Behaviors and volumes of infarction were observed, and microdialysis was applied to monitor the concentrations of glucose, lactate, pymvate and glutamate around the infarct foci at 1, 3, 10 and 30 d after permanent MCAO. Results Behaviors'score was lower in MCAO+HBO group than the others (P<0.05). The infarct volume from day 3 to day 30 was significantly smaller in MCAO+HBO group than in the other 2 groups (P<0.05). The lactate and pyruvate ratio was increased after MCAO in three groups, but they were lower in the MCAO+HBO group than in the others at day 1 and day 3 (P<0.05). The glutamate concentration was increased after MCAO, peaked at 3 d, but at day 1 and day 3 the glutamate concentration was lower in the MCAO+HBO group (P<0.05). Conclusions HBO treatment could protect the brain from infarction through improving the energy metabolism and decreasing the excitatory amino acids disorders around the infarct foci after MCAO in rabbits. In order to improve the therapeutic efficacy of HBO, it should be performed as possible.