[Effect of electroacupuncture of different acupoints on myoelectrical activities of the uterus in rats].

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 P, L4, and SP6 for 20 min.

RESULTS

(1)In nonpregnant 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 PA6, both frequency and amplitude of fast waves nd 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.