低强度810nm半导体激光照射对大鼠视神经损伤后视网膜脑源性神经营养因子的影响

目的观察低强度810 nm半导体激光照射对大鼠视神经钳夹伤后视神经再生的影响。方法健康成年Wistar大鼠44只,体重180～220 g,分成激光治疗组20只、单纯损伤组16只、正常对照组8只,每组按治疗时间又分成1、3、6和9周4个时间点。标准的视神经钳夹伤模型制备成功后,激光治疗组行激光照射,照射参数：光斑直径5 mm,照射功率60 mW,时间3 min,经皮至视神经损伤处,每日照射1次。单纯损伤组及正常对照组在进行激光照射时,激光器无功率输出。激光治疗1、3、6和9周后测量视网膜中脑源性神经营养因子（BDNF）mRNA的含量。结果激光治疗组大鼠视神经损伤后1周视网膜中的BDNFmRNA的含量达到最高,随后降低;治疗后1、3、6和9周与同一时间单纯损伤组视网膜中的BDNFmRNA表达相比有所提高（P〈0.05）。结论低强度810 nm半导体激光照射能促进视神经钳夹伤后视神经再生,增加视网膜中BDNF mRNA的表达。

The Effect of 810 nm Low Level Semiconductor Laser on the Expression of Brain Derive Neurotrophic Factor in the Retina after Optic Nerve Injury

Objective To determine whether or not 810 nm low power Ga-Al-As laser treatment can stimulate the regeneration of damaged optic nerves by measuring the expression of brain derive neurotrophic factor(BDNF). Methods Forty-four Wistar rats weighing 180-220 g were randomly divided into the laser therapy group,injury group and normal group,which consist of 20,16 and 8 rats respectively.Each group was subdivided into the 1st,3rd,6th and 9th week subgroups.Standardized crushing of optic nerves was applied to make the model.Then the rats in the laser therapy group were given 60 mW laser of a spot diameter of 5mm on the injured optic nerve for 3 minutes every day.The injury and normal groups received the same treatment with no laser output.The expression of BDNFmRNA was detected with RT-PCR respectively after 1,3,6 and 9 weeks of treatment. Results After the optic nerve was injured,the expression of BDNFmRNA reached the peak one week after the injury and then dropped.At the 1st,3rd,6th and 9th week after the injury,the expression of BDNFmRNA in the laser therapy group was significantly higher than that in the injury group. Conclusions 810 nm low power Ga-Al-As laser can promote the BDNFmRNA expression of rats with optic nerve injury and repair axonal regeneration of neural.