Effects of electroacupuncture at different acupoints on changes of uterine myoelectricity induced by oxytocin and progesterone in pregnant rats.
OBJECTIVE
To observe the effects of electroacupuncture (EA) at different acupoints on abnormal changes of uterine myoelectric activities in pregnant rats so as to analyze the specificity of regulative effects of the acupoint.


METHODS
Forty-eight pregnant (18-20 days) Wistar rats were randomly divided into control group (n=10), "Sanyinjiao" (SP 6) group (n=9), "Neiguan" (PC 6) group (n=10), "Hegu" (LI 4) group (n=8), and "Sanyinjiao plus Hegu" group (n= 11). These rats were anesthetized by intraperitoneal injection of a mixture solution of 1.5% chloralose (50mg/kg) and 25% urethane (420mg/kg). Electrohysterogram (EHG) was recorded by using a pair of stainless steel electrodes inserted into the subserous layer of the left mid part of the uterus. The reference electrode was placed in the adjoining subcutaneous tissue of the incision. Oxytocin and progesterone were given to the local uterus nearby the recording electrode to induce excitement and suppression of myoelectric activities of the uterus respectively. EA (2mA, 5/15Hz) was carried out at the above-mentioned acupoints separately for 20 min, and the influence of EA on changes (amplitude and frequency) of fast waves and slow waves of the uterine myoelectric activity was analyzed.


RESULTS
As compared with control group, EA at SP6 plus LI4 and at SP6 alone had a significantly inhibitory effect on oxytocin-induced increase in the frequency and amplitude of both fast and slow waves (P<0.05); and EA at LI4 had a markedly inhibitory effect on the amplitude of fast waves (P<0.05). EA at PC6 had no any marked effect on both frequency and amplitude of fast and slow waves of EHG (P>0.05). Compared with control group, EA at SP6 plus LI4 and at SP6 alone could relieve or significantly relieve progesterone-induced suppression of the frequency and amplitude of both fast and slow waves (P<0.05); and the effects of EA at SP6 plus LI4 appeared earlier and lasted longer than those of EA at SP6; while EA at LI4 and PC6 had no obvious effect on progesterone-induced changes of the frequency and amplitude of both fast and slow waves (P>0.05).


CONCLUSIONS
EA at SP6 plus LI4 and at SP6 alone has a dual-directional regulative effect on abnormal EHG, the effect of EA at SP6 plus LI4 is the strongest, EA at SP6 the secondary, EA at LI4 the weakest, and EA at PC6 shows no effect. In short, EA at different acupoints have their own relative specificity in regulating abnormal uterine myoelectric activities.
Chen
Shuping
S
Institute of Acupuncture & Moxibustion, China Academy of Chinese Medical Sciences, Beijing 100700, China.
Liu
Junling
J
Gao
Yonghui
Y
D015669:Acupuncture Points; D000818:Animals; D015671:Electroacupuncture; D004594:Electrophysiology; D005260:Female; D009215:Myometrium / Q000187:drug effects / Q000502:physiology; D010121:Oxytocin / Q000494:pharmacology*; D011247:Pregnancy; D011374:Progesterone / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects / Q000502:physiology*
D011374:Progesterone; D010121:Oxytocin