Objective: To observe the effect of acupuncture at "open" or "close" time and in "host" or "guest" sequence on uterine contraction in late pregnancy rats so as to explore the regularities of acupoint application.
Methods: A total of 32 pregnant rats were divided into "open/host-guest" (OHG) group, "open/guest-host" (OGH) group, "close/host-guest" (CHG) group and pregnancy group, with 8 cases in each. Eight normal rats were made up of normal control group. According to Ling Gui Ba Fa (Eight Laws of Spirit Turtle), acupuncture was given to "Zhaohai" (KI 6), "Lieque" (LU 7), "Hegu" (LI 4) and "Sanyin-jiao" (SP 6) first or later separately. For example, in OHG group, KI6 (host point, being in opening time) was punctured first with the acupuncture needle manipulated for 5 min, then, LU7 (guest point) punctured and stimulated for 5 min, LI4 (corresponding point of KI6) for 20 min, and then, SP6 (another corresponding point) was punctured and stimulated for 5 min in order. In CHG group, KI6 (being in closing time) was needled for 5 min first, followed by puncturing LU7, LI4 and SP6 for 5 min, 20 min, and 5 min separately in sequence. The uterine tension and uterine contraction frequency were measured by using a tension transducer.
Results: In comparison with normal control group, uterine smooth muscular tension and contraction frequency increased significantly in model group, and after acupuncture stimulation in OHG, OGH and CHG groups (P < 0.01, P < 0.05). Compared with model group, uterine tension of CHG group was significantly lower in the 8th time course after acupuncture (15-20 min after removing acupuncture needle, P < 0.05). No significant differences were found among model, OHG and OGH groups, and among OHG, OGH and CHG groups in uterine tension and contraction frequency (P > 0.05).
Conclusion: "Close-host-guest needling" can reduce uterine tension, which is likely to have significance in maintaining a stable environment of the uterus during pregnancy.