Hunter R H F
Institute for Reproductive Medicine, Hannover Veterinary University, Bünteweg, Hannover, Germany.
Mol Reprod Dev. 2008 Jan;75(1):167-74. doi: 10.1002/mrd.20776.
To avoid inappropriate conclusions being drawn from the extensive use of in vitro preparations of sperm-oviduct epithelial binding, it is recalled that events in the genital tract of mammals are regulated by the gonads, primarily by their changing secretion of steroid hormones. Key observations from in vivo models are used to emphasise the dynamic interactions between viable sperm cells and the caudal (distal) portion of the oviduct isthmus, the site of the functional sperm reservoir. These include (1) pre-ovulatory arrest and epithelial binding of intact sperm cells and thereby suppression of completion of capacitation, (2) peri-ovulatory activation and release from binding of discrete sub-populations of competent spermatozoa, and (3) post-ovulatory liberation of large numbers of spermatozoa. These observations underline the influence of endocrine regulation of sperm binding and release by peri-ovulatory Graafian follicles, a point brought out by the enhanced sperm release prompted by diverse treatments with solutions of progesterone. In the light of this evidence, the suitability of in vitro preparations for clarifying physiological events should be questioned, especially if myosalpingeal catecholamines diffusing out of the autonomic nervous system contribute to sperm activation and/or release. None of this is to infer that sperm cells themselves are without influence on their epithelial binding reaction(s). Nor is it to suggest that in vitro models of sperm-oviduct binding are without relevance to the development of sperm evaluation technologies. However, pre-ovulatory sperm-epithelial binding and a regulated peri-ovulatory release should be seen as vital tactics in the overall strategy of achieving successful monospermic fertilisation.
为避免因广泛使用精子 - 输卵管上皮结合的体外制剂而得出不恰当的结论，需谨记哺乳动物生殖道中的事件受性腺调节，主要是性腺分泌的类固醇激素变化的调节。体内模型的关键观察结果用于强调活精子细胞与输卵管峡部尾端（远端）之间的动态相互作用，输卵管峡部尾端是功能性精子储存库的所在部位。这些观察结果包括：（1）排卵前完整精子细胞的停滞和上皮结合，从而抑制获能的完成；（2）排卵前后有能力的精子离散亚群的激活和从结合中释放；（3）排卵后大量精子的释放。这些观察结果强调了排卵周围格拉夫卵泡对精子结合和释放的内分泌调节作用，这一点通过用孕酮溶液进行多种处理促使精子释放增加得以体现。鉴于这些证据，应质疑体外制剂用于阐明生理事件的适用性，尤其是如果自主神经系统扩散出的输卵管肌层儿茶酚胺有助于精子激活和/或释放。这并不是说精子细胞本身对其上皮结合反应没有影响。也不是说精子 - 输卵管结合的体外模型与精子评估技术的发展无关。然而，排卵前精子 - 上皮结合和受调节的排卵周围释放应被视为实现成功单精子受精总体策略中的重要策略。
