Effects Of Estrogen And IFN-γ On Apoptosis In HPG Axis Of Ovariectomized Rats

Hypothalamic-Pituitary-gonad (HPG) axis is important to regulation mechanisms of neuroreproduction. The balance of a great variety cytokines, neurotransmitters and hormones and their receptors with complex coordination mechanisms is the basic to matain the balance of immune-nero-endocrine network. If the expressions of the matters above-mentioned lose balance, the structure and effunction of the tissue may vary, and then the cells may ageing and apoptosis. In order to study the regulation mechanisms of hormones and cytokines to this variation for estrogen deficiency, ovariectomizedrat (OVX) modelwas made and sensitive immunohistochemical SP method was used to study the expressions of the apoptosis associated protein Bcl-2 and Bax in this pathologic state and in the state of treated with 17-βestrogen and Interferon-γ( IFN-γ). The main rusults were as followed:1. The expressions of Bcl-2 and Bax in hypothalami of rat: In 35 nucleuses in hypothalamus of the rats, include supraoptic nucleus, periventricular nucleus, arcuatus nucleus, hypothalamic ventromedialis nucleus and medial mamillary nucleus, et al, Bcl-2 and Bax immunohistochemical positive substances were located in these nucleuses and main located in cellular membrane, cytoplasm and caryotheca. After ovariectomized, relative expresions of Bcl-2 positive productions(μ2) tapered with the cours and to be the minumum after 4 weeks, concurrently, theμ2 of Bax increased, and to be the maximum after 4 weeks, which had significant difference with the SHAM group(P<0.05). After treated with 17-βestrogen, theμ2 of Bcl-2 increased and had remarkable difference with OVX group(P<0.05), but theμ2 of Bax had different in different nucleus, it decreased significantly in supraoptic nucleus, arcuate nucleus,et al, which had remarkable difference with OVX group(P<0.05); and it had no significant variation in periventricular nucleus, hypothalamic nucleus,et al. After treated with 17-βestrogen and 200 IU IFN-γtogether, theμ2 of Bcl-2 had very significant difference with OVX group(P<0.01), and had significant difference with OVX+E2 group(P<0.05),but had no remarkble difference with SHAM group(P>0.05). The total tendency of theμ2 of Bax was the to OVX+E2 group, it also had very significant difference with OVX group(P<0.01) in the nucleus which theμ2 of Bax decreased. Compared with OVX +E2 group, theμ2 of Bcl-2 and Bax of the grouop treated with 17-βestrogen and 50 IU/800 IU IFN-γtogether had no significant difference (P>0.05). 2. The expressions of Bcl-2 and Bax in pituitary of rat: Bcl-2 and Bax immunohistochemical positive substances were located in both and neurohypophysis in cellular membrane, cytoplasm.The number of Bcl-2 and Bax positive products in neurohypophysis is obviously less than that in adenohypophysis . After ovariectomized, relative expresions of Bcl-2 positive productions(μ2) tapered with the cours and to be the minumum after 4 weeks, concurrently, theμ2 of Bax increased, and to be the maximum after 4 weeks, which had significant difference with the SHAM group(P<0.05). After treated with 17-βestrogen, theμ2 of Bcl-2 increased and had remarkable difference with OVX group(P<0.05), and theμ2 of Bax decreased and had significant difference with OVX group(P<0.05) too. After treated with 17-βestrogen and 200 IU IFN-γtogether, theμ2 of Bcl-2 had very significant difference with OVX group(P<0.01), and had significant difference with OVX+E2 group(P<0.05),but had no remarkble difference with SHAM group(P>0.05). The total tendency of theμ2 of Bax was the to OVX+E2 group, it also had very significant difference with OVX group(P<0.01) in the nucleus which theμ2 of Bax decreased. Compared with OVX +E2 group, theμ2 of Bcl-2 and Bax of the grouop treated with 17-βestrogen and 50 IU/800 IU IFN-γtogether had no significant difference (P>0.05).The result aboved indicate that the cells of hypothalami and pituitary were more sensitive to the apoptosis in the state of lacking estrogen. Ectogenic physiological dose estrogen and proper does IFN-γhave important protected effect on the hypothalami neuron and pituitary in a certain period, which can regulating the express and the ratio of the contents of Bcl-2 and Bax.