OBJECTIVETo observe the influence of silencing Connexin43 (Cx43) expression of partial acupoints on acupuncture effect, so as to probe into the mechanism of acupuncture treatment for primary dysmenorrhea.

METHODSThe primary dysmenorrheal rat model made by oxytocin and RNA interference (RNAi) technology was used to silence the expression of Cx43 in acupoints. Fifty SD female rats were divided into five groups, a normal group (N), a model group (M), an acupuncture group (A), an acupuncture plus interference group (A+I), an acupuncture plus interference control group (A+IC). RT-PCR method was used to observe the oxytocin receptor (OTR) and vasopressin receptor (VPR) mRNA expressions in the uterus in each group. Plasma prostaglandin E2 (PGE2) and PGF2alpha levels were detected by radioimmunoassay and ELISA, respectively.

RESULTS(1) The times of writhing body (9.43 +/- 3.87 and 10.28 +/- 4.23) were significantly lower and the latency period of writhing body (12.43 +/- 3.46, 11.00 +/- 3.65) were longer in the group A and the group A+IC as compared with (15.43 +/- 5.13, 17.00 +/- 3.87) and (7.57 +/- 1.99, 8.43 +/- 2.57) in the group M and group A+I (P < 0.05), respectively. (2) The levels of Cx43 mR NA level and protein expression of acupoint in the group A+I were significantly lower than those of the group N (P < 0.05). (3) OTR and VPR mRNA in the uterus in the group A and the group A+IC were significantly lower than those in the group M and the group A+I (P < 0.05), with no significant difference between the group M and the group A+I (P > 0.05). (4) As compared with the group M, PGE2 level increased and PGF2alpha level decreased in the group A and the group A+IC (P < 0.05).

CONCLUSIONSilencing Cx43 expression of partial acupoint can inhibit effectively the effect of acupuncture through decreasing OTR and VPR in endometrium of the dysmenorrheal rat and adjusting the prostaglandins (PGs) synthesis system, which possibly is one of the mechanisms of acupuncture for treatment of primary dysmenorrhea.