“合谷-三阴交”穴不同的电针和留针时间组合对大鼠怀孕后期子宫收缩的影响

Effect of Electroacupuncture at "Hegu" (LI 4) with Different Stimulation Duration in Combination with Needle Retention in "Sanyinjiao" (SP 6) for Different Time on Uterine Contractility in Late-Stage Pregnant Rats

目的：对比先“合谷”后“三阴交”穴不同的电针刺激时间组合对大鼠怀孕后期子宫收缩的影响。方法：选健康成年雌性Wistar大鼠60只，应用2X2析因试验设计方法，分为4个电针组（以针“合谷”穴20min或40min与加针“三阴交”穴5min或20min组合）、正常对照组及模型对照组。电针的同一对正负极连接双侧同名穴，簇形波，频率20Hz，强度1～3．5V。于子宫中段安放电极，通过肌肉张力换能器记录子宫收缩幅度、频率，作为判断宫缩变化的指标。结果：先针“合谷”穴、次针“三阴交”穴后，二穴共同留针时间的长短对子宫收缩的影响更为重要，留针5min较20min更能促进子宫收缩。而单独先针“合谷”穴期间留针20min或40min对子宫收缩影响不大。结论：针刺“舍谷一三阴交”穴促分娩的最佳时间组合是先针刺“合谷”穴20min，再加针“三阴交”穴5min。

Objective：To study the effect of electroaoupuncture （EA） at “Hegu”（LI 4） with different stimulation duration in combination with needle retention in “Sanyinjiao”（SP 6） for different duration on uterine contraction in late-stage pregnant rats. Methods： A total of 50 late-stage pregnant （ 19th day after pregnancy） Wistar rats were randomized into control group, LI 4-EA 20 min＋SP 6-needling （N）-5 min （i.e., EA stimulation of LI 4 for 20 min first and then SP 6 was punctured with the needle retained for 5 min without electrical stimulation, similar expression in the following groups）, LI 4-EA-20 min＋SP 6-N-20 min, LI 4EA-40 min ＋ SP 6-N-5 min, LI 4-EA-40 min ＋ SP 6-N-20 min groups with 10 cases in each group according to the requirements of 2×2 factorial experiment design. In addition, other 10 non-pregnancy Wistar rats were used as normal control group. EA （20 Hz, 1-3.5 V） was applied to LI 4 for 20/40 min in the abovementioned 4 EA groups respectively. A muscular tension transducer was fixed to the mid-segrnent of the uterus for detecting the amplitude, frequency and contractility （amplitude × frequency） of the uterine contraction. Results： In comparison with normal control group, the amplitude, frequency, and contractility of the uterine contraction in control group increased significantly （P〈 0.05）. Comparison between factor A （LI 4：EA-20/40 min） and factor B （SP 6： neeclle kept in place for 5/20 min） among the 4 EA groups showed that 5- 10 min and 15-20 min after removal of the needle, both factor A and factor B had no significant influence on the amplitude of the uterine contraction; factor B could significant raise the frequency and contractility of the uterus contraction （P〈 0.05, 0.01）; and the effects of SP 6-N-5 min in increasing the frequency and contractility were markedly superior to those of SP 6-N-20 min （ P〈 0.05, 0.01 ）; while factor A had no marked influence on the frequency and contractility of the uterus. Comparison of the 4 EA groups showed that 5- 10 min after removal of the acupuncture needle, the emplituda of the uterine contraction in LI 4-EA-20 min＋ SP 6-N-5 min group was markedly higher than that of LI 4-EA-20 min＋SP 6-N-20 min group; 5 min after needling SP 6 and 5- 10 min after removal of needle, the frequency of uterine contraction in LI 4-EA-40 min＋ SP 6-N-5 min group was significantly higher than that of LI 4-EA-40 min＋ SP 6-N-20 min group （P〈0.05）. Conclusion： EA of LI 4 plus needling SP 6 can promote the uterine ccntraction activity in pregnancy rats, and the best combination is EA LI20 min first plus meeding SP 65min later.