Lapointe Jérome, Roy Monica, St-Pierre Isabelle, Kimmins Sarah, Gauvreau Danny, MacLaren Leslie A, Bilodeau Jean-François
Unité de Recherche en Ontogénie et Reproduction, Centre de Recherche du Centre Hospitalier de l'Université Laval, Local T-1-49, 2705 Boulevard Laurier, Ste-Foy, Québec, Canada G1V 4G2.
Endocrinology. 2006 Dec;147(12):5600-10. doi: 10.1210/en.2005-1548. Epub 2006 Aug 24.
Nitric oxide (NO) is a free radical produced by the action of NO synthases (NOS) and is known to be involved in the regulation of many reproductive events that occur in the oviducts. The oviducts are highly specialized organs that play crucial roles in reproduction by providing an optimal environment for the final maturation of gametes, fertilization, and early embryo development. In this study, we analyzed the expression, hormonal regulation, and cellular distribution of neuronal, inducible, and endothelial NOS in different bovine oviduct segments to better understand the roles played by these enzymes in oviductal functions in vivo. Quantitative RT-PCR analysis revealed that NOS isoforms are hormonally regulated and differentially expressed along the oviduct throughout the estrous cycle. All NOS were highly expressed around the time of estrus, and immunohistochemistry studies determined that neuronal NOS, inducible NOS (iNOS), and endothelial NOS are differentially distributed in cells along the oviduct. Interestingly, our results showed that estradiol selectively up-regulates iNOS expression in the oviduct during the periovulatory period corresponding to the window of ovulation, oocyte transport, and fertilization. The resulting NO production by this high-output NOS may be of crucial importance for reproductive events that occur in the oviduct. This study provided the first demonstration that NO production is hormonally regulated in the mammalian oviducts in vivo. Our results suggest that neuronal NOS, iNOS, and endothelial NOS contribute to oviductal functions in a timely and site-specific manner.
一氧化氮（NO）是由一氧化氮合酶（NOS）作用产生的一种自由基，已知其参与输卵管中发生的许多生殖事件的调节。输卵管是高度特化的器官，通过为配子的最终成熟、受精和早期胚胎发育提供最佳环境，在生殖过程中发挥关键作用。在本研究中，我们分析了神经元型、诱导型和内皮型NOS在不同牛输卵管段中的表达、激素调节和细胞分布，以更好地了解这些酶在体内输卵管功能中所起的作用。定量逆转录聚合酶链反应（RT-PCR）分析显示，NOS同工型受激素调节，在整个发情周期中沿输卵管差异表达。所有NOS在发情期前后均高表达，免疫组织化学研究确定神经元型NOS、诱导型NOS（iNOS）和内皮型NOS在沿输卵管的细胞中差异分布。有趣的是，我们的结果表明，在与排卵、卵母细胞运输和受精窗口相对应的围排卵期，雌二醇选择性地上调输卵管中iNOS的表达。这种高产量NOS产生的NO可能对输卵管中发生的生殖事件至关重要。本研究首次证明体内哺乳动物输卵管中NO的产生受激素调节。我们的结果表明，神经元型NOS、iNOS和内皮型NOS以时间和位点特异性方式对输卵管功能有贡献。
