GaAs半导体激光照射足三里穴对人体痛阈的影响
作者：卞学平 张志宏 卞红艳
单位：卞学平 张志宏 山东省荣成市人民医院激光室(264300)卞红艳 山东省荣成市第二人民医院外科
关键词：激光；胃经穴位；痛阈
中国激光医学杂志990312摘要
目的 探讨GaAs半导体激光穴位照射对人体的镇痛效应。
方法 健康受试者30名分为3组，每组10名。(1)组采用GaAs半导体激光照射双侧足三里穴(GaAs组)，光斑直径0.2cm，脉冲频率95Hz，平均功率密度159mW/cm2，每侧穴位照射15min。(2)组以激光和低频电脉冲(LFEP)交替作用于双侧足三里穴(GaAs+LFEP组)，每侧穴位激光和LFEP各作用15min，激光参数同GaAs组，LFEP取可调锯齿状波，频率10Hz，刺激强度以受试者能耐受为限。(3)组为对照组，仅将激光照射头放置于双侧足三里穴上15min，但无激光输出。于照射足三里穴前及照射后15、30min，采用钾离子透入测痛法，分别测量受试者腹部和耳垂痛阈，观察照射前后痛阈变化，并进行组间比较。
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[HT5”H〗结果 GaAS组穴位照射后15和30min，腹部痛阈分别比照射前提高35.6%(P<0.05)和39.7%(P<0.01)，耳垂痛阈分别比照射前提高26.7%(P<0.05)和24.4%(P>0.05)；GaAs+LFEP组刺激穴位后15和30min，腹部痛阈分别提高42.3%(P<0.05)和44.9%(P<0.05)，耳垂痛阈均提高44.6%(P<0.05)。GaAs组和GaAs+LFEP组照射或刺激穴位后不同时间的痛阈变化分别与对照组比较，腹部痛阈增高幅度差异均有显著意义(P<0.05)；耳垂痛阈增高幅度GaAs组差异无显著性(P>0.05)；GaAs+LFEP组则差异有显著意义(P<0.05)。
结论 GaAs半导体激光照射足三里穴具有明显的镇痛效应，低频电脉冲可加强GaAs半导体激光的镇痛效应，并有全身性镇痛效应和镇痛后效应。
Effect of GaAs Semiconductor Laser Irradiation of Zusanli Acupoints on Pain
, 百拇医药
Threshold in Healthy Subjects
BIAN Xueping, ZHANG Zhihong,Department of Laser Medicine, The People's Hospital of Rong cheng City, Shandong, Rongcheng 264300
BIAN Hongyan
Department of Surgery, The Second People's Hospital of Rong cheng City, Shandong, Rongcheng
ABSTRACT
Objective The analgesic effect of semiconductor GaAs laser acupoints irradiation and its machanism of action wese investigated in healthy subjects.
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Methods 30 healthy subjects were equally divided into three groups: the GaAs laser acupoints irradiation group, the GaAs laser acupoints irradiation alternatively combined with low-frequency electropulse stimulation group and the control group with laser probe merdy placed on the acupoints for 15 min without any irradiation. All laser irradiations on bilateral acupoints lasted for 15 min with a light spot diameter of 0.2cm, pulse frequency of 95Hz and mean power density of 159 mW/cm2. The electropulse was induced by using an adjustable saw-tooth wave generator with a frequency of 10Hz. The pain thres holds were tested by potassium-ion density dolorimeter before, 15 and 30minutes after GaAs laser irradiation or alternatively combined with low-frequency ele ctropulse stimulation on bilateral Zusanli(v36) acupoints for 15 minutes. Changes in pain thresholds of the abdomen and the ear-lobe were recorded in the experimental groups, and were compared with those of the control group.
, 百拇医药
Results The pain thresholds of the abdomen and ear-lobe were elevated in both experimental groups 15 and 30 minutes after treatment. The elevated amplitudes of the pain thresholds of the abdomen were 35.6%(P <0.05) and 39.7% respectively (P<0.01) in the GaAs laser group, 42.3%(P<0.05) and 44.9(P<0.05) respectively in the GaAs laser alternalively combined with low-frequency electropulse stimulation group. The elevated amplitudes of pain thresholds of the ear-lobe were 26.7%(P<0.05) and 24. 4%(P>0.05) respectively in the GaAs laser group, both 44 .6%(P<0.05) in the GaAs laser alternatively combined with low-frequency electropulse stimulation group. Changes in pain thresholds of different time interval after treatment in both experimental groups were compared with those of the control group: all differences of the pain thresholds of the abdomen were significant(P<0.05), the differences of the pain thresholds of the ear-lobe were not significant(P >0.05) in the GaAs laser group, but the differences were significant(P<0.05) in the GaAs laser alternatively combined with low-freque ncy electropulse stimulation group.
, 百拇医药
Conclusions It is suggested that GaAs laser irradiation on Zusanli(v 36) acupoints may exert obvious analgesic effect, and if combined with low-freq uency electropulse stimulation it may further enhance the analgesic effect of the GaAs laser irradiation. Moreover, the combined treatment with both laser and low-frequency electropulse has a prolonged and general analgesic effect.
Key words Lasers; Acupoints, stomach meridian; Pain threshold
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我们以往的工作[1]表明，GaAs半导体激光照射足三里穴可显著提高家兔的基础痛阈。为了探讨GaAs半导体激光照射足三里穴对人体的镇痛效应，我们观察了GaAs半导体激光照射足三里穴对健康人痛阈的影响，现报告如下。
对象与方法
1.对象 随机选取无神经系统或疼痛性疾病的健康受试者30名，男、女各15名；年龄18～32岁，平均26岁±4岁。受试者随机分为3组，每组10名：(1)GaAs半导体激光穴位照射组(简称GaAs组)；(2)GaAs半导体激光加低频电脉冲(LFEP)穴位照射组(简称GaAs+LFEP组)；(3)模拟激光照射对照组(简称对照组)。受试者试验前2～3天禁服任何解热止痛类药物，禁饮酒。试验前停止剧烈活动6h。
2.仪器 上海产XYL型GaAs半导体激光综合治疗仪，波长904nm，脉冲输出，脉宽150ns，单脉冲峰值功率360mW，频率94～3256Hz，连续可调，平均功率3～5mW。附有LFEP刺激电极，分为可调波、断续波、疏密波和起伏波四种波型，频率0.5～100Hz，刺激强度0～90V，均连续可调。
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3.方法 受试者取平卧位，静卧休息30min，采用钾离子透入测痛法，将测痛仪无关电极浸生理盐水固定于受试者左前臂伸侧，笔式探测电极浸饱和KCl溶液，分别测试上腹剑突至脐连线中点及左耳垂中点基础痛阈。选用阶梯输出，电流强度0～10mA，阶宽1s，阶高0.1mA，以受试者感到探测点疼痛时的电流值为痛阈值，连测3次取其均值为照射前基础痛阈。然后进行穴位照射试验观察。
(1)GaAs组：将笔式激光照射头分别放置双侧足三里穴行激光照射，每侧15min，光斑直径0.2cm，脉冲频率95Hz，平均功率5mW，平均功率密度159mW/cm2。
(2)GaAs+LFEP组：将笔式激光照射头放置右侧足三里穴，LFEP电极固定于左侧足三里穴，各作用于穴位15min后两侧交换，再各作用于穴位15min。激光参数同GaAs组；LFEP取可调锯齿状波，频率10Hz，半球状电极直径2cm，刺激强度以受试者能耐受为限。
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(3)对照组：仅将激光照射头放置双侧足三里穴上各15min，但无激光输出。
试验结束后15和30min，仍采用钾离子透入测痛法分别测量腹部及耳垂痛阈，对所得结果以自身对照t检验和成组比较t检验进行统计学处理。
结 果
各组穴位照射前后腹部和耳垂痛阈的测定结果见表1。穴位照射前各组不同部位痛阈差异无显著意义(P>0.05)；穴位照射后GaAs组和GaAs+LFEP组腹部和耳垂基础痛阈均增高，与穴位照射前比较，除GaAs组照射后30min耳垂痛阈外，差异均有显著或非常显著意义(P<0.05或P<0.01)。
GaAs组与GaAs+LFEP组比较，穴位照射后不同时间腹部和耳垂痛阈差异无显著意义(均P>0.05)。GaAs组和GaAs+LFEP组穴位照射后不同时间腹部痛阈增高幅度与对照组比较，差异均有显著意义(P<0.05)；耳垂痛阈增高幅度的比较则显示GaAs组与对照组间差异无显著意义(P>0.05)，而GaAs+LFEP组与对照组间的差异有显著意义(P<0.05)。
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表1 GaAs半导体激光照射或加低频电脉冲刺激足三里穴对健康人腹部和耳垂痛阈的影响
(mA，
±s)
Tab.1 Effect on pain threshold of abdomen and ear-lobe by GaAs semiconductor laser irradiation(GaAs group) or combined with low-frequency electropulse irradiating(GaAs+LFEP group)Zusanliacupoints(mA,±s) 组别
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Groups
人数
Number of
Subject
腹部痛阈
Pain threshold of abdoman
耳垂痛阈
Pain threshold of ear-lobe
照射前
Before
irradiation
照后15min
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15min after
irradiation
照后30min
30minafter
irradiation
照射前
Before
irradiation
照后15min
15min after
irradiation
照后30min
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30min after
irradiation
GaAs
10
0.73±0.23
0.99±0.28*Δ
1.12±0.31**Δ
0.90±0.23
1.14±0.34*
1.12±0.38
GaAs+LFEP
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10
0.78±0.23
1.11±0.30*Δ
1.13±0.30*Δ
0.92±0.32
1.33±0.36*Δ
1.33±0.40*Δ
对照组Controlgroup
10
0.76±0.29
0.72±0.31
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0.75±0.26
0.91±0.34
0.94±0.41
0.93±0.30
*与照射前比较Compared with the data before irradiation，P<0.05 **与照射前比较Compared with the data before irradiation，P<0.01 Δ与对照组比较Compared with control roup,P<0.05讨 论
激光穴位照射有明显的镇痛效应并成功地应用于临床麻醉和治疗疼痛性疾病已有报道[2,3]。以往激光穴位照射镇痛效应的研究多采用He-Ne激光[4]，而对GaAs半导体激光穴位照射镇痛效应的研究报道较少。激光生物学理论认为，激光对生物组织的效应与激光波长、输出方式、剂量、照射方式等密切相关。有实验表明近红外谱段激光较可见光谱段激光生物学效应强，脉冲输出激光较连续输出激光刺激强度大[5]。 GaAs 半导体激光波长范围在 830～
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904nm，为近红外谱段，对生物组织穿透比He-Ne激光约深2倍[6]，加之以脉冲方式输出，反射散射因素较小，是一种较理想的物理治疗光源。
本组观察表明，GaAs半导体激光照射足三里穴可明显提高健康人腹部和耳垂基础痛阈，照射后15和30min，腹部痛阈分别提高35.6%(P<0.05)和39.7%(P<0.01)，耳垂痛阈分别提高26.7%(P<0.05)和24.4%(P>0.05)；GaAs半导体激光照射加低频电脉冲刺激足三里穴后15和30min，腹部痛阈分别提高42.3%(P<0.05)和44.9%(P<0.05)，耳垂痛阈均提高44.6%(P<0.05)。虽然两组间痛阈提高幅度差异无显著意义，但GaAs半导体激光加低频电脉冲组腹部和耳垂痛阈增高幅度均大于单用GaAs半导体激光组，提示低频电脉冲刺激穴位可加强激光的镇痛效应，与我们以往的动物实验结果[1]相似。不同部位痛阈变化的组间比较结果表明，单用GaAs半导体激光照射足三里穴可使同经络线腹部痛阈增高，而非经络线耳垂痛阈增高不明显(P>0.05)；GaAs半导体激光与低频电脉冲交替作用于足三里穴，则不但可使同经络线腹部痛阈提高，亦能使非经络线耳垂痛阈显著提高，具有全身性镇痛效应，并有明显的镇痛后效应。
, 百拇医药
关于GaAs半导体激光穴位照射镇痛的机制，我们以往的动物实验结果表明GaAs半导体激光照射加低频电脉冲刺激足三里穴位所产生的镇痛效应可被阿片样受体特异阻断剂纳洛酮所逆转，从而提示GaAs半导体激光照射足三里穴可激活内源性镇痛系统，促使内源性吗啡样物质释放而产生镇痛效应[1]。近年刘新等[7]报道，低功率半导体激光照射可缓解肌肉紧张，改善血液循环和组织代谢，降低致痛物质浓度，从而缓解疼痛，减轻或消除疼痛性疾病的恶性循环。其确切机制有待进一步深入探讨。
参考文献
1 卞学平，于志勤，刘德民. 半导体砷化镓激光穴位照射镇痛效应的研究. 针刺研究，1989，14：379-382.
2 卞学平，曹任江，王秀文，等. 激光穴位照射-针刺复合麻醉在疝修补术中的应用. 中国针灸，1991，11：28-31.
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3 王利军，卞学平，刘永连. 氦-氖激光穴位深部照射治疗坐骨神经痛疗效观察. 激光杂志，1991，12：273-275.
4 虞乐华. 低功率氦-氖激光穴位照射的镇痛机理. 中华理疗杂志，1992， 15：177-179.
5 Basford JR. Low intensity laser therapy: still not an established clinical tool. Lasers Surg Med, 1995, 16: 331-342.
6 李峻亨，高孟林. 半导体激光器——激光医学发展推广的希望. 中国激光医学杂志，1996，5：125-127.
7 刘新，李胜利，陈家骅，等. 半导体激光疼痛治疗的研究. 应用激光，1997，17：186-188.
(收稿日期：1998-11-09), 百拇医药
单位：卞学平 张志宏 山东省荣成市人民医院激光室(264300)卞红艳 山东省荣成市第二人民医院外科
关键词：激光；胃经穴位；痛阈
中国激光医学杂志990312摘要
目的 探讨GaAs半导体激光穴位照射对人体的镇痛效应。
方法 健康受试者30名分为3组，每组10名。(1)组采用GaAs半导体激光照射双侧足三里穴(GaAs组)，光斑直径0.2cm，脉冲频率95Hz，平均功率密度159mW/cm2，每侧穴位照射15min。(2)组以激光和低频电脉冲(LFEP)交替作用于双侧足三里穴(GaAs+LFEP组)，每侧穴位激光和LFEP各作用15min，激光参数同GaAs组，LFEP取可调锯齿状波，频率10Hz，刺激强度以受试者能耐受为限。(3)组为对照组，仅将激光照射头放置于双侧足三里穴上15min，但无激光输出。于照射足三里穴前及照射后15、30min，采用钾离子透入测痛法，分别测量受试者腹部和耳垂痛阈，观察照射前后痛阈变化，并进行组间比较。
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[HT5”H〗结果 GaAS组穴位照射后15和30min，腹部痛阈分别比照射前提高35.6%(P<0.05)和39.7%(P<0.01)，耳垂痛阈分别比照射前提高26.7%(P<0.05)和24.4%(P>0.05)；GaAs+LFEP组刺激穴位后15和30min，腹部痛阈分别提高42.3%(P<0.05)和44.9%(P<0.05)，耳垂痛阈均提高44.6%(P<0.05)。GaAs组和GaAs+LFEP组照射或刺激穴位后不同时间的痛阈变化分别与对照组比较，腹部痛阈增高幅度差异均有显著意义(P<0.05)；耳垂痛阈增高幅度GaAs组差异无显著性(P>0.05)；GaAs+LFEP组则差异有显著意义(P<0.05)。
结论 GaAs半导体激光照射足三里穴具有明显的镇痛效应，低频电脉冲可加强GaAs半导体激光的镇痛效应，并有全身性镇痛效应和镇痛后效应。
Effect of GaAs Semiconductor Laser Irradiation of Zusanli Acupoints on Pain
, 百拇医药
Threshold in Healthy Subjects
BIAN Xueping, ZHANG Zhihong,Department of Laser Medicine, The People's Hospital of Rong cheng City, Shandong, Rongcheng 264300
BIAN Hongyan
Department of Surgery, The Second People's Hospital of Rong cheng City, Shandong, Rongcheng
ABSTRACT
Objective The analgesic effect of semiconductor GaAs laser acupoints irradiation and its machanism of action wese investigated in healthy subjects.
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Methods 30 healthy subjects were equally divided into three groups: the GaAs laser acupoints irradiation group, the GaAs laser acupoints irradiation alternatively combined with low-frequency electropulse stimulation group and the control group with laser probe merdy placed on the acupoints for 15 min without any irradiation. All laser irradiations on bilateral acupoints lasted for 15 min with a light spot diameter of 0.2cm, pulse frequency of 95Hz and mean power density of 159 mW/cm2. The electropulse was induced by using an adjustable saw-tooth wave generator with a frequency of 10Hz. The pain thres holds were tested by potassium-ion density dolorimeter before, 15 and 30minutes after GaAs laser irradiation or alternatively combined with low-frequency ele ctropulse stimulation on bilateral Zusanli(v36) acupoints for 15 minutes. Changes in pain thresholds of the abdomen and the ear-lobe were recorded in the experimental groups, and were compared with those of the control group.
, 百拇医药
Results The pain thresholds of the abdomen and ear-lobe were elevated in both experimental groups 15 and 30 minutes after treatment. The elevated amplitudes of the pain thresholds of the abdomen were 35.6%(P <0.05) and 39.7% respectively (P<0.01) in the GaAs laser group, 42.3%(P<0.05) and 44.9(P<0.05) respectively in the GaAs laser alternalively combined with low-frequency electropulse stimulation group. The elevated amplitudes of pain thresholds of the ear-lobe were 26.7%(P<0.05) and 24. 4%(P>0.05) respectively in the GaAs laser group, both 44 .6%(P<0.05) in the GaAs laser alternatively combined with low-frequency electropulse stimulation group. Changes in pain thresholds of different time interval after treatment in both experimental groups were compared with those of the control group: all differences of the pain thresholds of the abdomen were significant(P<0.05), the differences of the pain thresholds of the ear-lobe were not significant(P >0.05) in the GaAs laser group, but the differences were significant(P<0.05) in the GaAs laser alternatively combined with low-freque ncy electropulse stimulation group.
, 百拇医药
Conclusions It is suggested that GaAs laser irradiation on Zusanli(v 36) acupoints may exert obvious analgesic effect, and if combined with low-freq uency electropulse stimulation it may further enhance the analgesic effect of the GaAs laser irradiation. Moreover, the combined treatment with both laser and low-frequency electropulse has a prolonged and general analgesic effect.
Key words Lasers; Acupoints, stomach meridian; Pain threshold
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我们以往的工作[1]表明，GaAs半导体激光照射足三里穴可显著提高家兔的基础痛阈。为了探讨GaAs半导体激光照射足三里穴对人体的镇痛效应，我们观察了GaAs半导体激光照射足三里穴对健康人痛阈的影响，现报告如下。
对象与方法
1.对象 随机选取无神经系统或疼痛性疾病的健康受试者30名，男、女各15名；年龄18～32岁，平均26岁±4岁。受试者随机分为3组，每组10名：(1)GaAs半导体激光穴位照射组(简称GaAs组)；(2)GaAs半导体激光加低频电脉冲(LFEP)穴位照射组(简称GaAs+LFEP组)；(3)模拟激光照射对照组(简称对照组)。受试者试验前2～3天禁服任何解热止痛类药物，禁饮酒。试验前停止剧烈活动6h。
2.仪器 上海产XYL型GaAs半导体激光综合治疗仪，波长904nm，脉冲输出，脉宽150ns，单脉冲峰值功率360mW，频率94～3256Hz，连续可调，平均功率3～5mW。附有LFEP刺激电极，分为可调波、断续波、疏密波和起伏波四种波型，频率0.5～100Hz，刺激强度0～90V，均连续可调。
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3.方法 受试者取平卧位，静卧休息30min，采用钾离子透入测痛法，将测痛仪无关电极浸生理盐水固定于受试者左前臂伸侧，笔式探测电极浸饱和KCl溶液，分别测试上腹剑突至脐连线中点及左耳垂中点基础痛阈。选用阶梯输出，电流强度0～10mA，阶宽1s，阶高0.1mA，以受试者感到探测点疼痛时的电流值为痛阈值，连测3次取其均值为照射前基础痛阈。然后进行穴位照射试验观察。
(1)GaAs组：将笔式激光照射头分别放置双侧足三里穴行激光照射，每侧15min，光斑直径0.2cm，脉冲频率95Hz，平均功率5mW，平均功率密度159mW/cm2。
(2)GaAs+LFEP组：将笔式激光照射头放置右侧足三里穴，LFEP电极固定于左侧足三里穴，各作用于穴位15min后两侧交换，再各作用于穴位15min。激光参数同GaAs组；LFEP取可调锯齿状波，频率10Hz，半球状电极直径2cm，刺激强度以受试者能耐受为限。
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(3)对照组：仅将激光照射头放置双侧足三里穴上各15min，但无激光输出。
试验结束后15和30min，仍采用钾离子透入测痛法分别测量腹部及耳垂痛阈，对所得结果以自身对照t检验和成组比较t检验进行统计学处理。
结 果
各组穴位照射前后腹部和耳垂痛阈的测定结果见表1。穴位照射前各组不同部位痛阈差异无显著意义(P>0.05)；穴位照射后GaAs组和GaAs+LFEP组腹部和耳垂基础痛阈均增高，与穴位照射前比较，除GaAs组照射后30min耳垂痛阈外，差异均有显著或非常显著意义(P<0.05或P<0.01)。
GaAs组与GaAs+LFEP组比较，穴位照射后不同时间腹部和耳垂痛阈差异无显著意义(均P>0.05)。GaAs组和GaAs+LFEP组穴位照射后不同时间腹部痛阈增高幅度与对照组比较，差异均有显著意义(P<0.05)；耳垂痛阈增高幅度的比较则显示GaAs组与对照组间差异无显著意义(P>0.05)，而GaAs+LFEP组与对照组间的差异有显著意义(P<0.05)。
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表1 GaAs半导体激光照射或加低频电脉冲刺激足三里穴对健康人腹部和耳垂痛阈的影响
(mA，
±s)Tab.1 Effect on pain threshold of abdomen and ear-lobe by GaAs semiconductor laser irradiation(GaAs group) or combined with low-frequency electropulse irradiating(GaAs+LFEP group)Zusanliacupoints(mA,
±s) 组别, http://www.100md.com
Groups
人数
Number of
Subject
腹部痛阈
Pain threshold of abdoman
耳垂痛阈
Pain threshold of ear-lobe
照射前
Before
irradiation
照后15min
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15min after
irradiation
照后30min
30minafter
irradiation
照射前
Before
irradiation
照后15min
15min after
irradiation
照后30min
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30min after
irradiation
GaAs
10
0.73±0.23
0.99±0.28*Δ
1.12±0.31**Δ
0.90±0.23
1.14±0.34*
1.12±0.38
GaAs+LFEP
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10
0.78±0.23
1.11±0.30*Δ
1.13±0.30*Δ
0.92±0.32
1.33±0.36*Δ
1.33±0.40*Δ
对照组Controlgroup
10
0.76±0.29
0.72±0.31
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0.75±0.26
0.91±0.34
0.94±0.41
0.93±0.30
*与照射前比较Compared with the data before irradiation，P<0.05 **与照射前比较Compared with the data before irradiation，P<0.01 Δ与对照组比较Compared with control roup,P<0.05讨 论
激光穴位照射有明显的镇痛效应并成功地应用于临床麻醉和治疗疼痛性疾病已有报道[2,3]。以往激光穴位照射镇痛效应的研究多采用He-Ne激光[4]，而对GaAs半导体激光穴位照射镇痛效应的研究报道较少。激光生物学理论认为，激光对生物组织的效应与激光波长、输出方式、剂量、照射方式等密切相关。有实验表明近红外谱段激光较可见光谱段激光生物学效应强，脉冲输出激光较连续输出激光刺激强度大[5]。 GaAs 半导体激光波长范围在 830～
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904nm，为近红外谱段，对生物组织穿透比He-Ne激光约深2倍[6]，加之以脉冲方式输出，反射散射因素较小，是一种较理想的物理治疗光源。
本组观察表明，GaAs半导体激光照射足三里穴可明显提高健康人腹部和耳垂基础痛阈，照射后15和30min，腹部痛阈分别提高35.6%(P<0.05)和39.7%(P<0.01)，耳垂痛阈分别提高26.7%(P<0.05)和24.4%(P>0.05)；GaAs半导体激光照射加低频电脉冲刺激足三里穴后15和30min，腹部痛阈分别提高42.3%(P<0.05)和44.9%(P<0.05)，耳垂痛阈均提高44.6%(P<0.05)。虽然两组间痛阈提高幅度差异无显著意义，但GaAs半导体激光加低频电脉冲组腹部和耳垂痛阈增高幅度均大于单用GaAs半导体激光组，提示低频电脉冲刺激穴位可加强激光的镇痛效应，与我们以往的动物实验结果[1]相似。不同部位痛阈变化的组间比较结果表明，单用GaAs半导体激光照射足三里穴可使同经络线腹部痛阈增高，而非经络线耳垂痛阈增高不明显(P>0.05)；GaAs半导体激光与低频电脉冲交替作用于足三里穴，则不但可使同经络线腹部痛阈提高，亦能使非经络线耳垂痛阈显著提高，具有全身性镇痛效应，并有明显的镇痛后效应。
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关于GaAs半导体激光穴位照射镇痛的机制，我们以往的动物实验结果表明GaAs半导体激光照射加低频电脉冲刺激足三里穴位所产生的镇痛效应可被阿片样受体特异阻断剂纳洛酮所逆转，从而提示GaAs半导体激光照射足三里穴可激活内源性镇痛系统，促使内源性吗啡样物质释放而产生镇痛效应[1]。近年刘新等[7]报道，低功率半导体激光照射可缓解肌肉紧张，改善血液循环和组织代谢，降低致痛物质浓度，从而缓解疼痛，减轻或消除疼痛性疾病的恶性循环。其确切机制有待进一步深入探讨。
参考文献
1 卞学平，于志勤，刘德民. 半导体砷化镓激光穴位照射镇痛效应的研究. 针刺研究，1989，14：379-382.
2 卞学平，曹任江，王秀文，等. 激光穴位照射-针刺复合麻醉在疝修补术中的应用. 中国针灸，1991，11：28-31.
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3 王利军，卞学平，刘永连. 氦-氖激光穴位深部照射治疗坐骨神经痛疗效观察. 激光杂志，1991，12：273-275.
4 虞乐华. 低功率氦-氖激光穴位照射的镇痛机理. 中华理疗杂志，1992， 15：177-179.
5 Basford JR. Low intensity laser therapy: still not an established clinical tool. Lasers Surg Med, 1995, 16: 331-342.
6 李峻亨，高孟林. 半导体激光器——激光医学发展推广的希望. 中国激光医学杂志，1996，5：125-127.
7 刘新，李胜利，陈家骅，等. 半导体激光疼痛治疗的研究. 应用激光，1997，17：186-188.
(收稿日期：1998-11-09), 百拇医药