电针足三里穴对Ⅲ度烫伤大鼠口服补液后胃排空率和胃黏膜血流的影响

Effect of electroacupuncture at Zusanli point on gastric emptying rate and gastric mucosal blood flow after oral resuscitation of full thickness scalded rats

目的研究电针足三里穴对Ⅲ度烫伤大鼠口服补液时胃排空率和胃黏膜血流的影响。方法采用随机数字表法将120只SPF级成年大鼠分为5组:假伤后胃内补液组(GR组)、烫伤后胃内补液组(SGR组)、烫伤后电针+胃内补液组(SGR+EA组)、双侧迷走神经切断+烫伤后胃内补液(VGX+SGR组)、双侧迷走神经切断+烫伤后电针+胃内补液组(VGX+SGR+EA组),每组24只。在1000 mL无菌蒸馏水中,加入3.5 g丙酮酸钠、3.5 g氯化钠,1.5 g氯化钾和20.0 g葡萄糖,配置丙酮酸钠口服补液盐(Pyr-ORS),调节pH值至7.35。将大鼠麻醉后分别行颈动脉、股静脉和股动脉分离术并置管。烫伤大鼠采用沸水(100℃,15 s)造成背部约35%总体表面积(TBSA)的Ⅲ度烫伤,假烫伤大鼠采用温水浸泡(37℃,15 s)。烫伤后即刻,每只大鼠给予皮下注射0.5 mL 0.9%氯化钠溶液和500 mL丁丙诺啡用于止痛。采用输液泵立即经胃管输注Pyr-ORS,持续1 h。VGX+SGR组和VGX+SGR+EA组大鼠烫伤前进行双侧迷走神经切断术。SGR+EA组和VGX+SGR+EA组,选择足三里穴进行针刺,连接电针仪,强度为2 mA,2~100 Hz,针刺深度7 mm,在给予烫伤大鼠Pyr-ORS的胃内补液后,持续电针刺激0.5 h。分别于烫伤后2、4 h检测各组大鼠胃排空率、胃黏膜血流量。数据比较采用单因素方差分析和LSD-t检验。结果烫伤后2、4 h,SGR组、SGR+EA组、VGX+EA组和VGX+SGR+EA组大鼠的胃排空率[2 h:(16.5±3.2)%、(22.6±3.7)%、(13.6±3.0)%、(14.2±3.2)%;4 h:(12.9±2.4)%、(17.1±2.3)%、(10.8±2.7)%、(12.7±2.5)%]均分别低于GR组[2 h:(45.9±4.6)%;4 h:(42.4±5.7)%],差异均有统计学意义[2 h:(t=18.18、13.67、20.37、19.60,P值均小于0.05);4 h:(t=28.29、24.71、28.67、27.96,P值均小于0.05)。SGR+EA组的胃排空率高于SGR组、VGX+SGR组和VGX+SGR+EA组,差异均有统计学意义[2 h:t=4.32、6.54、5.94,P值均小于0.05);4 h:(t=4.38、6.15、4.49,P值均小于0.05)]。烫伤后2、4 h,SGR组、SGR+EA组、VGX+EA组和VGX+SGR+EA组大鼠胃黏膜血流量[2 h:(54.0±7.3)、(74.6±8.7)、(42.0±5.5)、(45.2±6.2)BPU;4 h:(46.0±6.8)、(65.6±10.1)、(37.8±5.6)、(42.7±6.4)BPU]均分别明显低于GR组[2 h:(142.0±18.1)BPU;4 h:(127.4±16.5)BPU],差异均有统计学意义[2 h:(t=15.67、11.67、18.35、17.56,P值均小于0.05);4 h:(t=15.80、11.07、17.81、16.58,P值均小于0.05)];SGR+EA组与SGR组、VGX+SGR组和VGX+SGR+EA组比较,差异均有统计学意义[2 h:(t=6.28、10.97、9.53,P值均小于0.05);4 h:(t=5.58、8.33、6.63,P值均小于0.05)]。结论电针足三里穴能促进Ⅲ度烫伤大鼠口服补液后的胃排空率,增加胃黏膜血流,提高口服补液的疗效,其作用机制可能与兴奋迷走神经有关。

Objective To study the effect of electroacupuncture at Zusanli point on gastric emptying rate and mucosal blood flow after oral rehydration of full thickness scalded rats.Methods Using random number table method,120 rats were divided into 5 groups:sham+intragastric rehydration group(GR group),scald+intragastric rehydration group(SGR group),scald+electro-acupuncture+intragastric rehydration group(SGR+EA group),vagotomy+scald+intragastric rehydration group(VGX+SGR group)and vagotomy+scald+electro-acupuncture+intragastric rehydration group(VGX+SGR+EA group),with 24 rats in each group.In 1000 mL of sterile distilled water,3.5 g of sodium pyruvate,3.5 g of sodium chloride,1.5 g of potassium chloride,and 20.0 g of glucose were added,sodium pyruvate oral rehydration salt(Pyr-ORS)was configured,and the pH was adjusted to 7.35.After the rats were anesthetized,the carotid artery,femoral vein,and femoral artery were separated and the catheterization was did.The scalded rats were scalded with boiling water(100℃,15 s)for about 35%total body surface area(TBSA)of the back,and the scalded rats were immersed in warm water(37℃,15 s).Immediately after the scald,each rat was given a subcutaneous injection of 0.5 mL of 0.9%sodium chloride solution and 500 mL of buprenorphine for pain relief.Pyr-ORS was immediately infused via a gastric tube using an infusion pump for 1 h.Rats in the VGX+SGR group and the VGX+SGR+EA group underwent bilateral vagus nerve resection before burns.In the SGR+EA and VGX+SGR+EA groups,Zusanli point was selected for acupuncture and connected to an electroacupuncture instrument.The intensity was 2 mA,2 to 100 Hz,and the acupuncture depth was 7 mm.After rehydration,the electroacupuncture was continued for 0.5 h.The gastric emptying rate and gastric mucosal blood flow of each group were measured at 2 and 4 h after scald.Data were compared using one-way analysis of variance and t test.Results The gastric emptying rates of rats in the SGR group,SGR+EA group,VGX+EA group,and VGX+SGR+EA group[2 h:(16.5±3.2)%,(22.6±3.7)%,(13.6±3.0)%,(14.2±3.2)%;4 h:(12.9±2.4)%,(17.1±2.3)%,(10.8±2.7)%,(12.7±2.5)%were lower than those of rats in the GR group[2 h:(45.9±4.6)%;4 h:(42.4±5.7)%],the differences were statistically significant[2 h:(t=18.18,13.67,20.37,19.60;with P values below 0.05);4 h:(t=28.29,24.71,28.67,27.96;with P values below 0.05).The gastric emptying rates of rats in the SGR+EA group was higher than those of rats in the SGR group,VGX+SGR group and VGX+SGR+EA group,and the differences were statistically significant[2 h:(t=4.32,6.54,5.94;with P values below 0.05);4 h:(t=4.38,6.15,4.49;with P values below 0.05)].Gastric mucosal blood flow of rats in the SGR group,SGR+EA group,VGX+EA group,and VGX+SGR+EA group at 2 and 4 h after scald[2 h:(54.0±7.3),(74.6±8.7),(42.0±5.5),(45.2±6.2)BPU,4 h:(46.0±6.8),(65.6±10.1),(37.8±5.6),(42.7±6.4)BPU]were significantly lower than the GR group[2 h:(142.0±18.1)BPU;4 h:(127.4±16.5)BPU],the differences were statistically significant[2 h:(t=15.67,11.67,18.35,17.56;with P values below 0.05);4 h:(t=15.80,11.07,17.81,16.58;with P values below 0.05)];the gastric mucosal blood flow of rats in the SGR+EA group compared with SGR group,VGX+SGR group and VGX+SGR+EA group,the difference were statistically significant[2 h:(t=6.28,10.97,9.53;with P values below 0.05);4 h:(t=5.58,8.33,6.63;with P values below 0.05)].Conclusions Electro acupuncture at Zusanli point can promote the rate of gastric emptying,increase gastric mucosal blood flow,and improve the efficacy of oral rehydration in full thickness scalded rats.The mechanism may be related to the stimulation of the vagus nerve.