Hammouche Sadjia, Gernigon Thérese, Exbrayat Jean Marie
Laboratoire de Recherche en Zones Arides, Equipe Reproduction des petits Vertébrés, Faculté des Sciences Biologiques, Université des Sciences et de la Technologie de Houari Boumediene, PB 39 El Alia, Bab Ezzouar, Alger.
Folia Histochem Cytobiol. 2009;47(5):S95-S100. doi: 10.2478/v10042-009-0050-y.
In Mammals, opioid peptides are involved in various physiological processes including the reproductive function. The knowledge of the distribution of beta-endorphin, one of opioid peptides in Reptiles ovaries is very limited. Therefore, the present study used the lizard ovarian follicles to further elucidate the role of this peptide in steroidogenesis. In Uromastyx acanthinura, the localization of both this peptide and sex steroid hormone was investigated by the immunohistochemical approach. This technique was used to evaluate the distribution of these substances and their relationship. The beta-endorphin is strongly distributed in the granulosa cells and oocyte cytoplasm of the previtellogenic follicles in sexually quiescent lizards (winter) when steroidogenesis was interrupted. In spring, the signal became weak, or even absent, in the vitellogenic and previtellogenic follicles. The granulosa cells of the previtellogenic follicles showed an important synthesis of 17beta-estradiol. Females that did not undergo in vitellogenesis in spring showed the same profile than quiescent females of winter. These findings represent the first evidence of the presence of beta-endorphin in the ovary of this lizard. The seasonal variations observed in the reproductive cycle suggest that this opioid peptide is involved in the modulation of seasonal steroidogenesis.
在哺乳动物中，阿片肽参与包括生殖功能在内的各种生理过程。关于阿片肽之一的β-内啡肽在爬行动物卵巢中的分布情况，了解非常有限。因此，本研究利用蜥蜴的卵巢卵泡进一步阐明该肽在类固醇生成中的作用。在棘刺尾蜥中，通过免疫组织化学方法研究了这种肽和性类固醇激素的定位。该技术用于评估这些物质的分布及其关系。在性静止的蜥蜴（冬季）中，当类固醇生成中断时，β-内啡肽强烈分布于卵黄生成前卵泡的颗粒细胞和卵母细胞胞质中。在春季，卵黄生成卵泡和卵黄生成前卵泡中的信号变弱，甚至消失。卵黄生成前卵泡的颗粒细胞显示出重要的17β-雌二醇合成。春季未经历卵黄生成的雌性与冬季静止雌性表现出相同的特征。这些发现首次证明了这种蜥蜴卵巢中存在β-内啡肽。在生殖周期中观察到的季节性变化表明，这种阿片肽参与了季节性类固醇生成的调节。
