We have previously demonstrated the presence of Angiotensin (Ang)-(1-7) in rat ovary homogenates and its stimulatory effect on estradiol and progesterone production. The present study was undertaken to identify the cellular localization of Ang-(1-7) and its receptor Mas in the rat ovary in the different phases of the estrous cycle. Ang-(1-7) and Mas were localized by immunohistochemistry and Mas mRNA expression was assessed by RT-PCR. Immunostaining for both Ang-(1-7) and Mas was found in all phases of the estrous cycle, particularly in the thecal and interstitial cells, as well as in regressing corpora lutea. However, granulosa cells were positive only in antral and preovulatory follicles at proestrus and estrus phases. This pattern contrasted with the distribution of the octapeptide Ang II, which was abundant in granulosa but not in theca cells. In addition, the expression of Mas mRNA was demonstrated in all estrous cycle phases. Angiotensin-converting enzyme activity did not vary between estrous cycle phases, whereas prolyl endopeptidase activity was significantly higher in diestrus and neutral endopeptidase activity was significantly higher in metestrus. These data provide the first evidence that new RAS components are dynamically expressed in the ovary across the rat estrous cycle. Further functional studies should clarify the role of Ang-(1-7) signaling through Mas receptor in the regulation of ovarian physiology.

我们以前已经证明了大鼠卵巢匀浆中血管紧张素（Ang）-（1-7）的存在及其对雌二醇和孕激素产生的刺激作用。进行本研究以鉴定在动情周期的不同阶段中Ang-（1-7）及其受体Mas在大鼠卵巢中的细胞定位。通过免疫组织化学对Ang-（1-7）和Mas进行定位，并通过RT-PCR评估Mas mRNA的表达。在动情周期的所有阶段都发现了对Ang-（1-7）和Mas的免疫染色，特别是在鞘细胞和间质细胞以及黄体退化中。然而，颗粒细胞仅在发情和发情期的窦房和排卵前卵泡中呈阳性。这种模式与八肽Ang II的分布形成对比，后者在颗粒细胞中丰富，但在卵泡膜细胞中却不丰富。另外，在所有发情周期阶段均证实了Mas mRNA的表达。在发情周期各阶段之间，血管紧张素转化酶的活性没有变化，而在雌蕊中，脯氨酰内肽酶的活性显着较高，而在肠胃中，中性内肽酶的活性显着较高。这些数据提供了新的RAS成分在整个大鼠发情周期的卵巢中动态表达的第一个证据。进一步的功能研究应阐明通过Mas受体的Ang-（1-7）信号在卵巢生理调节中的作用。而脯氨酰内肽酶活性在二头肌中明显更高，中性内肽酶活性在肠胃中更高。这些数据提供了新的RAS成分在整个大鼠发情周期的卵巢中动态表达的第一个证据。进一步的功能研究应阐明通过Mas受体的Ang-（1-7）信号在卵巢生理调节中的作用。而脯氨酰内肽酶活性在二头肌中明显更高，中性内肽酶活性在肠胃中更高。这些数据提供了新的RAS成分在整个大鼠发情周期的卵巢中动态表达的第一个证据。进一步的功能研究应阐明通过Mas受体的Ang-（1-7）信号在卵巢生理调节中的作用。