Leung P S, Sernia C
Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong.
J Mol Endocrinol. 2003 Jun;30(3):263-70. doi: 10.1677/jme.0.0300263.
The blood-borne renin-angiotensin system (RAS) is known best for its role in the maintenance of blood pressure and electrolyte and fluid homeostasis. However, numerous tIssues show intrinsic angiotensin-generating systems that cater for specific local needs through actions that add to, or differ from, the circulating RAS. The male reproductive system has several sites of intrinsic RAS activity. Recent focus on the epididymis, by our laboratories and by others, has contributed important details about the local RAS in this tIssue. The RAS components have been localized morphologically and topographically; they have been shown to be responsive to androgens and to hypoxia; and angiotensin has been shown to influence tubular, and consequently, fluid secretion. Components of the RAS have also been found in the testis, vas deferens, prostate and semen. Angiotensin II receptors, type 1 and, to a lesser extent, type 2 are widespread, and angiotensin IV receptors have been localized in the prostate. The roles of the RAS in local processes at these sites are still uncertain and have yet to be fully elucidated, although there is evidence for involvement in tubular contractility, spermatogenesis, sperm maturation, capacitation, acrosomal exocytosis and fertilization. Notwithstanding this evidence for the involvement of the RAS in various important aspects of male reproduction, there has so far been a lack of clinical evidence, demonstrable by changes in fertility, for a crucial role of the RAS in male reproduction. However, it is clear that there are several potential targets for manipulating the activity of the male reproductive system by interfering with the locally generated angiotensin systems.
血源性肾素-血管紧张素系统（RAS）因其在维持血压以及电解质和液体平衡方面的作用而最为人所知。然而，许多组织显示出内在的血管紧张素生成系统，这些系统通过与循环RAS相加或不同的作用来满足特定的局部需求。男性生殖系统有几个内在RAS活性位点。我们实验室和其他实验室最近对附睾的关注，为该组织中局部RAS提供了重要细节。RAS成分已在形态学和拓扑学上定位；已证明它们对雄激素和缺氧有反应；并且已证明血管紧张素会影响小管，进而影响液体分泌。RAS成分也在睾丸、输精管、前列腺和精液中被发现。1型血管紧张素II受体广泛存在（2型受体存在程度较低），血管紧张素IV受体已在前列腺中定位。尽管有证据表明RAS参与这些部位的局部过程，但RAS在这些部位的局部过程中的作用仍不确定，尚未完全阐明，不过有证据表明其参与小管收缩、精子发生、精子成熟、获能、顶体胞吐和受精。尽管有证据表明RAS参与男性生殖的各个重要方面，但迄今为止，还缺乏通过生育能力变化来证明RAS在男性生殖中起关键作用的临床证据。然而，显然有几个潜在靶点可通过干扰局部生成的血管紧张素系统来操纵男性生殖系统的活性。
