| Acupuncture in reproductive medicine today, as a therapy has become established in not only Orient but also Western medicine. We have observed that repeated electroacupuncture (EA) might stimulate the activity of the adrenals, and enhance the circulation level of estrogen in the ovariectomized rats. Androgens, produced primarily in the adrenal glands, can be converted (aromatized) into estrogens at extraglandular sites. Estrogen synthesized within these sites is biologically active in a paracrine or intracrine fashion, although it may enter the circulation and increase the circulating levels of estrogen. Corticotropin-releasing hormone (CRH) is the principal hypothalamic neurohormone in the control of the hypothalamus-pituitary-adrenal axis (HPAA). Then it is open pivotal questions that whether CRH involves the central effects of EA on adrenal and how it interacts with gonadotropin-releasing hormone (GnRH) which is the hypothalamic key molecular of hypothalamus-pituitary-ovary axis (HPOA).Objective To explore the central mechanism by which the adrenal activity was evoked; and the source of the increased circulation estrogen, the expressions and releases of corticotropin-releasing hormone (CRH) and gonadotropin-releasing hormone (GnRH) in the hypothalamuses were observed; the extragonadal aromatization was detected; the mRNA expressions of adrenal 17-alpha hydroxylase/ 17,20-lyase (P450CYP17) which is the key enzyme catalyzing the synthesis of androgens was examined.Methods Female rats were divided into five groups: 1) intact (INT), 2) intact with EA (INT+EA), 3) ovariectomized (OVX), 4) ovariectomized with EA (OVX+EA) and 5) ovariectomized for 4-6 months (OVX-M). "Guanyuan" acupoint (RN4), "Zhongji" acupoint (RN3), "Zigongxue" acupoints (EXTRA22) and "Sanyinjiao" acupoint (SP6) were adopted. The stimulation was generated by an EA apparatus and lasted for 30 min (8:00-10:00 AM), Q.D, for 3 days altogether. The stimulation parameters were 2 mA of density and a low-burst frequency of 3 Hz. Push-pull perfusion technique, radioimmunoassay, radiometric assay, immunohistochemistry, immunofluorescent double labeling histochemistry combining laser confocal scanning microscope (CLSM), Western blot, in situ hybridization, Northern blot, Dot blot and RT-PCR were used.Results 1. EA might significantly increase the blood concentration of E2 and the GnRH neurons number which located at the rostral medial septum, Broca diagonal band nucleus and the medial preoptic area in OVX rats. The number of CRH neurons at the medial section of one side nucleus paraventricular (PVN) was higher in OVX+ EA than that in INT, INT+EA and OVX groups. And the CRH output showed a significant elevation in OVX+EA group during the EA procedure and further increase immediately after the EA. Exciting enough, only in the OVX+EA rats, we observed the co-localization of CRH-ir and GnRH-ir in one cell of hypothalamic PVN by immunofluorescent double labeling histochemistry combining CLSM. 2. The 58-kDa aromatase protein and aromatase mRNA expressions in the OVX+EA rats' SA adipose tissues showed higher levels than those from corresponding tissues in the INT and INT+EA rats. And the expressions of aromatase mRNA and protein in the OVX+EA rats' liver tissues increased significantly compared with those in the OVX rats. The mRNA/protein expressions of the anteroventral periventricular nucleus (AVPv), the medial basal hypothalamus and the suprachiasmatic–preoptic area aromatase increased significantly compared with those in the OVX rats. The expressions of P450CYP mRNA at the adrenal cortexes of OVX+EA rats increased significantly compared with those in OVX ones. 3. In OVX4M group, the blood E2 concentrations increased significantly, and it was nearly half of the normal level in OVX6M rats. The expressions and releases of CRH and GnRH in hypothalamuses, the extragonadal aromatization in SA adipose and liver tissues, the mRNA expressions of P450CYP17 in adrenals were all gradually normalized in OVX5M/6M rats.Conclusions 1. CRH might be an important f...
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