The effect of acupuncture on uterine contraction induced by oxytocin

Preterm labor (PTL) is one of the main causes of fetal mortality and morbid ity in obstetrical medicine. Current methods of treatment are not very effe ctive and often have significant side effects. For this reason new methods of preventing PTL are currently being sought. In Western medicine the newes t development is oxytocin antagonists. In Oriental medicine acupuncture and moxibustion are being utilized for the purpose of stopping PTL. The goals of this study were to determine if acupuncture in pregnant rats can suppres s oxytocin induced uterine contractions and to compare these results with t hose inhibited by an oxytocin antagonist. Uterine contractions were induced by continuous infusion of exogenous oxytocin. The first fetus in one uteri ne horn near the ovarian end was removed and distilled water-filled cathete r was inserted into that vacated amniotic sac to measure uterine contractio ns as intrauterine pressure changes. Two acupoints of Ho-Ku (LI-4) and San- Yin-Chiao (Sp-6) were selected for acupuncture and Kuan-Yuan (Co-4) was use d for moxibustion. The oxytocin-induced uterine contractions were significa ntly suppressed by acupuncture on the LI-4 (p < 0.05), but not by Sp-6. Sti mulation of Co-4 by moxibustion had no significant (p > 0.05) tocolytic eff ect. The administration of oxytocin antagonist eliminated all the uterine c ontractions induced by oxytocin. The application of acupuncture to re-stimu late the activity that was suppressed by the oxytocin antagonist did not pr oduce any positive results. However, prostaglandins did cause the uterus to contract. In conclusion, acupuncture on LI-4 was found to suppress uterine contractions induced by oxytocin in the pregnant rat. If acupuncture is si milarly effective in counteracting the effects of oxytocin in women, then t his may an alternative medical treatment for women in preterm labor.