Marengo Susan Ruth
Urology Research Laboratory, School of Medicine, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106-4931, USA.
Anim Reprod Sci. 2008 Apr;105(1-2):52-63. doi: 10.1016/j.anireprosci.2007.11.018. Epub 2007 Nov 26.
The epididymis has been understudied, in part due to its cancer resistance and the development of effective technologies for sperm injection and in vitro fertilization. However, it is worthy of study because--absent advanced reproductive technology--its proper function is essential for conceiving children: sperm leaving the testis are immature and nonfertile. Epididymal functions can be divided into several general categories (1) concentration of sperm; (2) functional maturation; (3) storage in a quiescent state until ejaculation; (4) removal of degenerating sperm; (5) provision of appropriate conditions for survival; (6) transport by the myoid cells; (7) protection; (8) maintenance of the blood epididymal barrier. In the past decade investigators have focused on those maturational changes of the integral proteins of the sperm plasma membrane which are directly related to sperm-ova interactions. It has traditionally been thought that changes in the sperm plasma membrane proteins were limited to simple binding or removal of proteins or interactions with the proteases, glycosylases and glycotransferases present. However, the epididymis can also release secretory products in bulk through apical blebs and inject integral membrane proteins with epididymosomes which fuse with the plasma membrane. The epididymis also activates and cleaves enzymes present on the sperm surface (e.g., germ cell angiotensin converting enzyme), thus enabling them to modify proteins on the sperm membrane. Aside from the need to understand epididymal function relative to the sperm, basic science on epididymal physiology is warranted because it may help us understand the functioning of androgens, protection of tissues from oxidative damage, and resistance to cancer and benign hyperplasic growth.
附睾一直未得到充分研究，部分原因是其具有抗癌性以及精子注射和体外受精等有效技术的发展。然而，它值得研究，因为在没有先进生殖技术的情况下，其正常功能对于受孕至关重要：离开睾丸的精子是不成熟且无生育能力的。附睾的功能可分为几个一般类别：（1）精子浓缩；（2）功能成熟；（3）在静止状态下储存直至射精；（4）清除退化的精子；（5）提供适宜的生存条件；（6）由肌样细胞运输；（7）保护；（8）维持血附睾屏障。在过去十年中，研究人员专注于精子质膜整合蛋白的那些与精子 - 卵子相互作用直接相关的成熟变化。传统上认为，精子质膜蛋白的变化仅限于蛋白质的简单结合或去除，或与存在的蛋白酶、糖基化酶和糖基转移酶的相互作用。然而，附睾也可以通过顶端小泡大量释放分泌产物，并将整合膜蛋白与附睾小体一起注入，附睾小体与质膜融合。附睾还激活并切割精子表面存在的酶（例如生殖细胞血管紧张素转换酶），从而使它们能够修饰精子膜上的蛋白质。除了需要了解附睾相对于精子的功能外，关于附睾生理学的基础科学也是必要的，因为它可能有助于我们理解雄激素的功能、组织免受氧化损伤的保护以及对癌症和良性增生性生长的抵抗力。
