Conduction Pathway Of The Acupuncture Signals On "Guanyuan" Acupoint (CV 4)-a Pseudorabies Virus Neural Tracing Study

Objective:On the basis of peripheral and central mechanism study of the acupuncture effect on "perimenopausal syndrome",we used ovariectomized rats as animal models to detect the neural pathway from "Guanyuan" acupoint to central nervous system with two PRV as neural tracers.It might provide the scientific foundation for the treatment of female reproductive endocrine diseases with acupuncture on "Guanyuan" acupoint.Methods:Forty-eight female SD rats were divided into four groups randomly:INT, INT+EA,OVX and OVX+EA.The rats in the groups of OVX and OVX+EA received the bilateral ovariectomy.Four weeks later,each rat was injected 10μl liquid containing 10⁷ plaque-forming units PRV(PRV-gG^--LacZ⁺ or PRV-gG^--TK^--EGFP respectively) on "Guanyuan"(CV 4) acupoint.30 minutes after PRV injection, INT+EA and OVX+EA were applied electroacupuncture on "Guanyuan" acupoint (CV 4) for 30 minutes,once a day,totally for 3 days.6 hours after the electro-acupuncture treatment,vaginal smears were made for observation of the change of vaginal exfoliative epithelinm cells.The level of blood E₂ in each group was examined by radioimmunoassay(RIA).At the 6 hours after the last electroacupuncture treatment,all rats were sacrificed and undergone the blood vessel perfusion with 4%paraformaldehyde solution.Then,the brains and spinal cords were removed immediately and cut into a 35μm sections by a freezing microtome.The sections were processed PRV-LacZ⁺ immunochemistry and PRV-EGFP immunofluorescence respectively.Results:(1) After EA treatment,vaginal smears showed an estrogen-dependent response,the exfoliative epithelinm cells reappeared in the OVX+EA;The blood E₂ level in the OVX+EA was significantly higher than that in the OVX(P＜0.05).(2) PRV-IR cells tracing with PRV-gG^--LacZ⁺ located widely in the spinal cord,brain stem,hypothalamus and cerebral cortex of each group.PRV-IR cells in some regions, such as Ms,ARC,DBN,PVN,which would be related to the endocrine function were reduced obviously(P＜0.05) in OVX and even more,the PRV-IR cells in VMH and LPO were barely observed(P＜0.01).But the PRV-IR cells in above regions were increased significantly(P＜0.05 or P＜0.01) in OVX+EA.No obvious changes were found in the number of PRV-IR cells between INT and INT+EA.(3) PRV-IR cells tracing with PRV-gG^--TK^--EGFP also located in the spinal cord,brain stem, hypothalamus and cerebral cortex of each group.PRV-IR cells in Ms,ARC,LPO and PVN were reduced markedly(P＜0.05) in OVX and no obvious differences were observed in the number of PRV-IR cells between INT and INT+EA(P＞0.05).Conclusions:When rats were under the normal physical state,the acupuncture signal might conduct along the neural pathway between "Guanyuan" and CNS.This neural pathway changed after ovariectomy in female rats,however,electroacupuncture on "Guanyuan" acupoint might promote the recovery of hypothalamic neural pathway in ovariectomized rat.It might provide the neuro-anatomical evidences for the conduction of acupuncture signal from the "Guanyuan" acupoints to central nervous system.