Identification, localization and functional activity of oxytocin receptors in epididymis
Identification, localization and functional activity of oxytocin receptors in epididymis
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DOI：
10.1016/s0303-7207(02)00101-6
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发表时间：
2002-07-31
影响因子：
4.1
通讯作者：
Maggi, M
中科院分区：
文献类型：
--
作者：
Filippi, S;Vannelli, GB;Maggi, M
催产素（OT）是一种神经垂体激素，在男性体内的生理功能尚不清楚。一些先前的研究表明，OT可能在射精过程中发挥作用，刺激精子从附睾储存中释放。本研究探讨了OT受体（OTR）在家兔和人附睾中的存在和功能。通过RT-PCR、Western印迹和结合试验，我们发现OTR基因和蛋白在人附睾中表达，并能刺激离体附睾的收缩。OTR的免疫定位表明该受体不仅存在于人附睾的平滑肌细胞中，而且也存在于上皮隔室中。在培养的兔附睾上皮（rEE）细胞中进行的实验表明，OT诱导另一种有效的附睾收缩刺激物内皮素-1（ET-1）的释放。通过使用特异性拮抗剂（BQ-123）阻断ET-1受体的ETA亚型，部分地抵消OT的收缩作用，表明两种肽在调节附睾收缩性中的正相互作用。最后，为了研究急性OT给药是否也会增加人类的精子释放，我们在精子采集前静脉注射OT（2.5 IU）治疗少精子症患者。在一项小型单盲研究中，我们发现与溶媒给药相比，OT的精子回收率几乎翻了一番。我们的研究结果表明，OT可能有生理功能，也在男性，控制附睾运动和精子通过男性生殖道的进展。(C)2002爱思唯尔科学爱尔兰有限公司保留所有权利。
Oxytocin (OT) is a neurohypophysial hormone with unclear physiological functions in the male. Several previous studies indicated that OT might have a role in the ejaculatory process, stimulating sperm release from the epididymal storage. In this study we investigated on the presence and function of OT receptor (OTR) in rabbit and human epididymis. By using RT-PCR, Western and binding studies, we found that OTR gene and protein is expressed in the human epididymis and stimulates in vitro contractility. The immunolocalization of OTR suggests that the receptor is not only present in the smooth muscle cells of the human epididymis but also in the epithelial compartment. Experiments performed in rabbit epididymal epithelial (rEE) cells in culture indicate that OT induces the release of an other potent stimulator of epididymal contractility, endothelin-1 (ET-1), Blocking the ETA subtype of the ET-I receptors, by using a specific antagonist (BQ-123), partially counteracts the contractile effect of OT, suggesting positive interactions between the two peptides in regulating epididymal contractility. Finally, to investigate whether an acute OT administration increases sperm release also in humans, we treated oligozoospermic patients with an intravenous bolus of OT (2.5 IU), just before sperm collection. In a small, single blind study, we found that OT almost doubled sperm retrieval when compared with vehicle administration. Our results indicate that OT might have physiological functions also in the male, controlling epididymal motility and sperm progression through the male genital tract. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.