电针与褪黑素合用对大鼠应激性胃溃疡的影响

Effects of melatonin and electroacpuncture cotreatment on stress-induced gastric ulcers in rats

目的:观察电针与褪黑素合用对束缚-浸水应激大鼠胃溃疡指数、胃黏膜超氧化物歧化酶活性和丙二醛含量的影响,并与电针或褪黑素单独使用结果做比较。方法:实验于2004-10/2005-06在咸宁学院医学院生理教研室完成。①选用70只雄性SD大鼠,2～3月龄,体质量(250±30)g。将动物按随机抽签法分为5组:正常组、应激组、褪黑素+应激组、电针+应激组、电针+褪黑素+应激组。②正常组:不造模,不予处理。褪黑素+应激组、电针+应激组、应激组:分别于造模前30min腹腔注射褪黑素(Sigma公司产品,20mg/kg)、电针干预、腹腔注射含体积分数0.05乙醇的等体积生理盐水。电针+褪黑素+应激组:腹腔注射褪黑素(20mg/kg)后电针干预(用CDM1-2型双频针麻治疗仪电针刺激大鼠双侧后肢足三里穴位,电刺频率为4～16Hz,强度按1,2,3Ⅴ顺序增递电压,每个强度电针干预10min,共30min)再造模。③应激性溃疡模型制备:用乙醚轻度麻醉大鼠,将四肢及头部束缚于木板上。大鼠清醒后,将木板垂直浸于23℃水中,水面平胸骨剑突处。④浸水6h后处死大鼠剖腹,于胃幽门和贲门两处用线结扎,并向胃腔内注入40g/L甲醛溶液8～10mL。30min后沿大弯侧将胃剪开展平,观察溃疡发生情况。计算溃疡指数(损伤面的长度<1.0mm为1分;1.0～2.0mm为2分;2.0～3.0mm为3分;3.0～4.0mm为4分,>4.0mm将其分割若干段,每段按上法计算,溃疡宽度>1.0mm则分值×2,全胃得分之和为胃溃疡指数)。⑤取大鼠胃黏膜,制成组织匀浆液,取出上清液按南京建成生物工程研究所提供的试剂盒说明书检测超氧化物歧化酶活性、丙二醛含量。⑥组间计量资料差异比较采用t检验。结果:大鼠70只均进入结果分析,每组14只(进行胃溃疡指数计算7只,胃组织匀浆超氧化物歧化酶活性及丙二醛含量测定7只)。①胃溃疡指数:应激组明显高于褪黑素+应激组和电针+应激组(P<0.01),褪黑素+电针+应激组明显低于褪黑素+应激组和电针+应激组(P<0.01)。②胃黏膜超氧化物歧化酶活性:应激组明显低于正常组(P<0.01),褪黑素+应激组和电针+应激组明显高于应激组(P<0.01),明显低于电针+褪黑素+应激组(P<0.05,0.01)。③胃黏膜丙二醛含量:应激组明显高于正常组(P<0.01),褪黑素+应激组和电针+应激组明显低于应激组(P<0.01,0.05),明显高于电针+褪黑素+应激组(P<0.05)。结论:褪黑素或电针对应激性胃黏膜损伤有保护作用,该作用的发挥可能与抑制体内的过氧化反应有关,且电针与褪黑素合用对胃黏膜的保护作用更为显著。

AIM：To observe the effects of melatonin （MT） and electroacupuneture （EA） used together on the gastric ulcer index （UI）4 superoxide dismutase （SOD） activity and malnndialdehyde （MDA） content in rats induced by restraint and water immersion, and compare with effects of only MT nr EA. METHODS：The experiment was conducted at the Department of Physiology, School of Medical, Xianning College between October 2004 and June 2005.①Totally 70 male SD rots of 2-3 months old and （250±30） g weight were randomized into 5 groups： Control group, stress group, MT＋stress group, EA＋stress group and MT＋EA＋stress group. ②Control group： No model establishment and no treatment was performed. Stress group, MT＋ stress group and EA＋stress group： The rats accepted introperitnneal injection of MT （20 mg/kg, produced by Sigma Company） and equal volume saline containing ethanol of 0.05 volume fraction as well as EA treatment separately at 30 minutes before model establishment. MT＋EA＋stress group： Rats accepted＇ EA treatment [CDM1-2 double frequency acupuncture anesthetic unit was used to give EA stimulation to Zusanli （ST 36） in frequency of 4-16 Hz, and electric pressure increased gradually in order of 1, 2 and 3 V intensity, with 10 minutes of each intensity and totally for 30 minutes] after intraperitnneal injection of 20 mg/kg MT, followed by model establishment, ③Model establishment of stress ulcer： Rats were mildly anesthetized with ether, and the head and limbs were restrained on a board, which was vertically immersed in 23 ℃ water as soon as rats came around, with the water surface was equal to the xiphistemum of： rots.④After 6-hour water immersion, rats were executed to perform ventrotomy and deligated at gastric pyloros and cardiac orifice. Then gastral cavity was injected with 40 g/L formaldehyde solution （8-10 mL）, and 30 minutes later stomach was sheared and rolled out to observe ulcer occurrence and calculate UI. （Length of injured side： 〈 1.0 mm as score 1; 1.0-2.0 mm as score 2; 2.0-3.0 mm as score 3; 3.0--4.0 mm as score 4; If 〉 4.0 mm, ulcer was divided into several segments and calculated according to above metheds. Scores were doubled if width was more than 1.0 ram, then total score of whole stomach was UI.）⑤Gastric mucous membrane was selected to produce tissue homogenate fluid, and the supematant was transferred to detect SOD activity and MDA content with test kit instruction provided by Nanjing Jiancheng Biological Engineering Institute. ⑥The t test was used for comparison of measurement data between groups. REULTS： Totally 70 rats entered the result analysis with 14 ones in each group （Seven rats were used for gastric UI calculation and seven ones for detection of SOD activity and MDA content）. ①Gastric UI： The UI of rats in stress group was obviously higher than those of MT＋stress group and EA＋stress group （P 〈 0.01）, which were significantly higher than in MT＋EA＋stress group （P 〈 0.01）. ②SOD activity： The activity of rats in stress group was obviously lower than that of control group （P 〈 0.01）. and EA＋stress group and MT＋stress group were significantly higher than stress group （P 〈 0.01）, but lower than MT＋EA＋stress group （P 〈0.05,0.01）.③ MDA content： ＇ The content of rats in stress group was significantly higher than that of control group （P 〈 0.01）.The EA＋stress group and MT＋stress group were obviously lower than stress group （P 〈 0.01,0.05）,but notably higher than MT＋EA＋stress group （P 〈 0.05）. CONCLUSION： Either MT or EA shows protective effects on the stressinduced gastric mucosa injury, whose mechanism is possibly related with inhibition of peroxidation reaction. What＇s more, cotreatment of MT and EA show more significant protective effects.