| As the diseases of prolonged pregnancy, difficult labor and high risk pregnancy were still the main factors affected security of mother and baby at the present, promoting labor has become very important to guarantee the smooth conduction of delivery and improve the puerperal security. Promoting labor includes two aspects of inducing labor and hastening labor. The common methods of promoting labor in the clinic are pharmacotherapy, mechanotherapy, cesarean section and so on, which always has contraindications or induce some side-effect. Therefore, seeking more safe, convenient and effective methods for promoting labor is an urgent task of obstetrics. Enhancing the research in this aspect also has important significance.It has been a long history in China to promote labor with acupuncture. Clinical studies indicate that acupuncture can strengthen the uterine contraction, ripen the cervix, shorten the process of labor, reduce the postpartum hemorrhage, relieve pain during labor, etc. Hegu (LI4) and Sanyinjiao (SP6) is a classical pair points for promoting labor with highest usage frequency. It was mentioned that needling LI4 firstly then SP6 afterward in promoting labor in a lot of medical classics and the early experimental research. It was also verified that using LI4 and SP6 at the same time caused antagonism. Therefore, based on the above needling order of those two points, this experiments aimed at seeking the best stimulating duration on points for promoting labor through comparing the influence on uterine contraction and endocrine system caused by different interval between LI4 and SP6 and different duration of retention needles in those two points, in order to provide scientific evidence for using points in the clinic. And the mechanism of influence on promoting labor by time factors was also the aim the experiment.Healthy grown-up female Wistar rats were the study objects, while electric acupuncture was the stimulate method. Factorial experiment with 2 factors and 2 levels was applied. Factor A was the interval between LI4 and Sp6, including 2 levels of 20min and 40min. Factor B was the duration of retention needles in those two points after needling SP6, also including 2 levels of 5min and 20min. Sixty rats were randomly divided into 6 groups: electric acupuncture group A, B, C and D (A group: needling LI4 20min firstly, then SP6 5min; B group: needling LI4 20min firstly, thenSP6 20min; C group: needling LI4 40min firstly, then SP6 5min; D group: needling LI4 40min firstly, then SP6 20min), normal control group and pregnant control group. The values of intensity, frequency and potency of uterine contraction and the contents of serum PGE2, E2, P and ratio of E2 and P were measured. The results were as follows: 1.In 20min after removing needles, there was no significant difference of intensity of uterine contraction caused by factor A and B, while significant difference of uterine contraction frequency was found, factor B was more important than factor A. The frequency in groups with retention needles for 5min after needling SP6 was significantly higher than those in groups with 20min level. It suggested the method of retention needles for 5min after needling SP6 regardless of duration of needling LI4 had better effect of strengthening uterine contraction, which was obtained mainly through increasing the frequency of uterine contraction.2.In group A and C, the frequency and potency of uterine contraction were in creased significantly in 5min when SP6 was needled. Then the increased uterine contraction caused by needling LI4 was promoted by SP6, showing the instant effect of acupuncture. And this effect also remained for 20min after the removal of needles, showing the lasting effect of acupuncture. It was suggested that the needling methods in group A and C made the coordinated function of LI4 and SP6 in promoting labor. While the method in A group was the best needling method to increase uterine contraction. There was no significant change in intensity and potency of uterine contrac... |
