Mechanism Of Signal Transduction Of Acupuncture Effects On Dysfunction Of HPOA In Ovariectomized Rats

Mechanism of signal transduction of acupuncture effects on dysfunction of HPOA in ovariectomized ratsPARTâ… Mechanism of the effect of acupuncture perfusateObjective:To compare the varieties and contents of the main neural information molecule in the perfusate from the hypothalamic medial preoptic area(MPOA) of the rat with normal sexual cycle or the ovariectomized rats treated by acupuncture in order to observe the differences and similarities of hypothalamic neuroendocrine signal conduction pathway under the physiological and pathological status,which might explore the mechanisms of neuroendocrine signal conduction/transduction of acupuncture therapeutic effect on perimenopausal syndrome.Methods:By using stereo-localization technique,push and pull perfusion of the rat brain nucleus,to collect the push and pull perfusion in hypothalamic MPOA at the different stages of the physiological sex cycle in female rats and the MPOA push and pull perfusate of the ovariectomized rats following acupuncture treatment(AP in short).The perfusate of the four different stages in rat physiological sexual cycle was microinjected into the ovariectomized rats MPOA to observe the effects on the changes of vaginal exfoliative cytology and the level of blood estradiol(E2).The contents of the GnRH,DA,GAB A,Glu,Asp and P-EP in the perfusate were detected by RIA and HPLC.Then the changes of the contents were compared and analyzed.Result:There were regular changes of the contents of the GnRH,DA,GAB A,Gly, Asp and P-EP in the perfusate of the four different stages of the rat physiological sexual cycle.After microinjection of the perfusate of four stages in the sexual cycle to the ovariectomized rats MPOA,some changes of the vaginal exfoliative cytology and the level of blood E₂ which like as the physiological sexual cycle might appear.After AP microinjection to the ovariectomized rat MPOA,the "acupuncture-like" effects on the vaginal exfoliative cytology and the level of blood E2 were observed in ovariectomized rats.Conclusion:The information molecule in the perfusate of the different stages of the physiological sexual cycle rats and acupuncture perfusate(AP) might be consisted of classical neurotransmitter,amino acid neurotransmitters and neuropeptide,and so on. They might be inherent and not produced by the effect of acupuncture specially and might be the neuroendocrine signal pathway for connection and modulation in both of nerve system and endocrine system;Acupuncture might cure perimenopausal syndrome via modulation of these information molecule synthesis and release. Acupuncture perfusate might be a neuroendocrine signal carrier of acupuncture curative effects for conduction/transfer acupuncture signal from one individual to another,which may provide a new thinking on study of acupuncture signal transduction in vitro and vivo.PARTâ…¡The effects of acupuncture perfusate on phosphorylation of ERK and P38 in hypothalamic slices with conditional incubationObjective:The technique of hypothalamic slices conditional incubation was used for observing the effect of the acupuncture perfusate on GnRH release from the hypothalamic slices and the effect of acupuncture perfusate on phosphorylation of ERK,P38 and the ERK/MAPK cascade was explored.An initial study of signal transduction pathway between the exterior and interior of GnRH neuron was performed.Methods:Under the condition of ice bath,the hypothalamus of ovariectomized rats was cut quickly into 2-3mm thick slices,which were incubated in the condition of acupuncture perfusate(AP) and artificial cerebrospinal fluid(IaCSF) respectively. Then the incubation fluid was collected,and the content of GnRH in the incubation fluids was detected by a special GnRH RIA.The thick slices were used in Western blot assay for the phosphorylation of ERK and P38.Result:After conditional incubation with AP the contents of GnRH in incubation fluid was about 55.49±10.47 pg/ml and 82.07±14.7 pg/ml following incubation with artificial cerebrospinal fluid.After AP conditional incubation,the release of GnRH from hypothalamic slices was obviously suppressed(P＜0.05) compared with the artificial cerebrospinal fluid incubation.The phosphorylation of ERK and P38 of the hypothalamic slices with AP conditional incubation was obviously suppressed.The results of computer image manipulation showed that the relatively optical density of pERK and tERK of the slices with AP conditional incubation and with artificial cerebrospinal fluid incubation was 0.0744±0.01,0.2364±0.0313,and the relatively optical density of pP38 and tP38 of the hypothalamic slices incubated with AP and with artificial cerebrospinal fluid was 0.173±0.013,0.4374±0.0413,suggesting the relatively optical density of ERK and P38 were restrained by AP significantly (P＜0.05).Conclusion:The AP of ovariectomized rat MPOA might inhibit the phosphorylation of ERK and P38 in GnRH neuron,then partly might attenuate the signal transduction pathway in GnRH neuron,resulting the part inhibition of the nuclear synthesis of GnRH,by which acupuncture might show the inhibitory effects on the release of GnRH cell.The acupuncture perfusate might carry about the "acupuncture curative signal",to be utilzed for a "pharmacological tool" for study of the mechanism on acupuncture curing female perimenopausal syndrome.