Experimental Study on the Modulation of Endometrial Receptivity in Chronically Stressed Rats by Liver Electroacupuncture with Liver Sparing and Nourishing Methods

目的：以电针为干预手段，通过观察慢应激大鼠模型合笼后妊娠率和胚胎着床数，以验证疏肝养肝法电针对于改善慢应激大鼠子宫内膜容受性的有效性。方法：采用慢性轻度不可预见性应激模型造模。首先，按照体重分层随机法将正常动情周期SD大鼠分为正常、模型、阳性对照、低频电针及高频电针5组，除正常组不给予任何刺激外，余4组大鼠按造模方法复制肝郁模型。其中模型组不给予任何治疗，阳性对照组给予阿司匹林0.01 mL/g灌胃；低频电针治疗组：刺激参数：连续波，2 Hz，1 mA，以局部肌肉颤动为度，留针20 min。高频电针治疗组：刺激参数：连续波，50 Hz，1 mA，以局部肌肉颤动为度，留针20 min。持续刺激三周后，进行行为测试并将动情期大鼠按照雌雄比2:1合笼，见阴道栓示为妊娠第1日。于妊娠第10日处死并观察各组大鼠妊娠率和着床点数。结果：除模型组有1只大鼠未妊娠外，其余四组均全部妊娠，模型组妊娠率与其它四组妊娠率的比较差异无统计学意义(P > 0.05)；与模型组比较，阳性对照组和低频、高频电针组的平均着床数明显上升(P OBJECTIVE: To verify the effectiveness of liver-sparing and method-supporting electroacupuncture in improving endometrial receptivity in slow-stressed rats by observing the pregnancy rate and the number of embryos implanted after caging in a slow-stressed rat model using electroacupuncture as an intervention. METHODS: A chronic mild unpredictable stress model was used for modeling. First, SD rats with normal estrous cycle were divided into 5 groups according to the weight stratified randomization method: normal, model, positive control, low-frequency electroacupuncture and high-frequency electroacupuncture. Except for the normal group, which was not given any stimulation, the remaining 4 groups of rats were replicated in the liver-depression model according to the modeling method. The model group was not given any treatment, and the positive control group was given aspirin 0.01 mL/g by gavage; the low-frequency electroacupuncture treatment group: stimulation parameters: continuous wave, 2 Hz, 1 mA, to the extent of local muscle tremor, leave the needle in place for 20 min; the high-frequency electroacupuncture treatment group: stimulation parameters: continuous wave, 50 Hz, 1 mA, to the extent of local muscle tremor, leave the needle in place for 20 min. three weeks of continuous stimulation, the rats were then subjected to behavioral tests. After three weeks of continuous stimulation, behavioral tests were performed and rats in estrus were combined in cages according to a 2:1 ratio of males to females, and vaginal plugs were seen on day 1 of gestation. The rats were killed on the 10th day of gestation, and the pregnancy rate and the number of implantation points were observed in each group. RESULTS: Except for one rat in the model group which was not pregnant, all the other four groups were pregnant, and the difference between the pregnancy rate of the model group and that of the other four groups was not statistically significant (P > 0.05); compared with the model group, the average number of beds made in the positive control group and the low-frequency and high-frequency electro-acupuncture groups increased significantly (P < 0.05); compared with the normal group, the average number of beds made in the model group decreased significantly (P < 0.05); Comparing the high-frequency electroacupuncture group with the low-frequency electroacupuncture group, the average number of beds significantly increased (P < 0.05). CONCLUSION: Electroacupuncture with the method of liver sparing and liver nourishing has better efficacy in the treatment of chronic stress infertile rats, and the effect of high-frequency electroacupuncture is better than that of low-frequency electroacupuncture stimulation, which proves that it can regulate the endometrial receptivity and increase the average number of beds by improving the state of chronic stress in rats.