目的:研究不同穴位和频率的电针刺激对成年大鼠视神经切断后视网膜神经节细胞(节细胞)存活的作用。方法:54只成年SD大鼠接受右侧视神经眶内切断术及节细胞荧光金(Fluoro Gold,FG)逆行性标记后,随机分为9组,对照组(含2、7、14 d组)及不同穴位、频率和伤后存活时间组合的电针组(含假穴4/20 Hz电针7 d组、百会穴4/20 Hz电针7 d组、睛明穴2 Hz电针7 d组、睛明穴4/20 Hz电针2、7、14 d组),每组6只动物。结果:(1)睛明穴4/20 Hz电针7 d组存活节细胞平均密度显著高于对照、假穴和百会穴组(P〈0.01),而假穴和百会穴组与对照组间无显著性差异;(2)睛明穴2 Hz与睛明穴4/20 Hz电针7 d组节细胞密度虽无显著性差异,但均显著高于对照7 d组(P〈0.01);(3)分别以4/20 Hz电针刺激睛明穴2、7、14 d,与对照组相同时间点相比,仅在伤后7 d出现节细胞密度的显著增高(P〈0.01)。结论:以4/20 Hz与2 Hz两种不同频率的电针刺激睛明穴,均能在成年大鼠视神经切断后7 d延缓节细胞的死亡。就本研究所观察的不同穴位和频率而言,电针的神经保护作用取决于针刺穴位而非电针频率。
Objective: To investigate the effects of electroacupuncture(EA) with different acupoints and frequencies on the survival of axotomized retinal ganglion cells(RGCs) after optic nerve transection(ONT) in adult rats.Methods: After right ONT and retrograde Fluoro Gold(FG)-labeling of surviving RGCs,54 adult SD rats were randomly divided into 9 groups(n=6): control 2,7,14 d groups,and EA groups with different combinations of acupoints,frequencies and survival time after ONT(Sham-acupoint 4/20 Hz EA 7 d,Baihui 4/20 Hz EA 7 d,Jingming 2 Hz EA 7 d,Jingming 4/20 Hz EA 2,7,14 d groups).Results:(1) The mean density of surviving RGCs in Jingming 4/20 Hz EA 7 d group was significantly higher(P〈0.01) than those in control,sham acupoint and Baihui 7 d groups,but no significant difference was found among the last 3 groups;(2) The mean RGC densities in Jingming 2 Hz and 4/20 Hz EA 7 d groups were similar to each other,but were significantly higher(P〈0.01) than that in control 7 d group;(3) Significantly higher RGC density could only be detected in Jingming 4/20 Hz EA 7 d group(P〈0.01) when the RGC densities in Jingming 4/20 Hz EA 2,7,14 d groups were compared to control groups at the corresponding time points,respectively.Conclusion: 2 Hz and 4/20 Hz EA treatments in Jingming acupoints could delay the death of injured RGCs for a certain period after ONT in adult rats.It is indicated that it is the acupoint,but not the EA frequency,that determines the production of neuroprotection by EA after ONT.