Objective: To observe the effect of electroacupuncture(EA) of different acupoints on electrical activities of the uterus in rats.Methods: A total of 79 Wistar rats anesthetized with mixture solution of 1.5% chloralose(50 mg/kg) and 25% urethrane(420 mg/kg

i.p.).In the first part of this study

40 non-pregnant rats were randomized into control

"Neiguan"(PC 6)

"Hegu"(LI 4) and "Sanyinjiao"(SP 6) groups

with 10 cases in each group.In the second part of this study

39 pregnant rats were evenly randomized into control

"Neiguan"(PC 6) and "Sanyinjiao"(SP 6) groups

with 13 cases in each group.Electrohysterogram was recorded by using a bipolar stainless steel electrode inserted in the sub-perimetrium layer of the mid part of the uterus.EA(2 mA

5/15 Hz) was respectively applied to bilateral PC6

LI4

and SP6 for 20 min.Results: 1) In non-pregnant rats

compared with control group

the amplitude and frequency of fast waves(burst action potentials) and the amplitude of slow waves in SP6 increased significantly(P<0.05)

and EA of LI4 had a similar effect in increasing the frequency of fast waves;while following EA of PC6

both frequency and amplitude of fast waves and the frequency of slow waves decreased significantly(P<0.05).In comparison with PC6 group

most indexes of SP6 and LI4 groups during EA and 0-5 min after EA presented significant differences(P<0.05

0.001).2) In pregnant rats

compared with control group

both the amplitude and frequency of fast waves and the amplitude of slow waves of the electrohysterogram in SP6 group increased significantly(P<0.05) and lasted a longer!time;while the frequency of both fast and slow waves decreased considerably in PC6 group(P<0.05).Comparison between SP6 and PC6 groups showed significant differences in the frequency and amplitude of fast waves and the frequency of slow waves during EA and after EA(P<0.05).Conclusion: EA of SP6 and LI4 can activate the myoelectrical activities of the uterine in both non-pregnant and pregnant rats

and the effect of EA of SP6 is stronger

whereas EA of PC6 can inhibit the myoelectrical activities of the uterine.Different acupoints have their relatively specific effect.