Mobilisation of stored calcium in the neck region of human sperm - a mechanism for regulation of flagellar activity
Mobilisation of stored calcium in the neck region of human sperm - a mechanism for regulation of flagellar activity
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DOI：
10.1387/ijdb.072535kb
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发表时间：
2008-01-01
影响因子：
0.7
通讯作者：
Publicover, Stephen
中科院分区：
文献类型：
--
作者：
Bedu-Addo, Kweku;Costello, Sarah;Publicover, Stephen
钙信号在精子生理学中发挥着关键作用，密切参与顶体反应、趋化性和超激活的调节。在这里，我们简要地描述了体细胞中钙调节的机制，以及这些机制在成熟精子中发挥作用的方式。然后，我们考虑最近的数据，从这个和其他实验室的精子的反应，三种化合物：孕酮和一氧化氮（卵丘的产品）和4-氨基吡啶。所有这些化合物在精子头部和颈部后部区域诱导钙信号，并且当以适当浓度施用时，改变鞭毛活性，引起近端鞭毛的不对称弯曲。我们认为，这些影响反映了一个共同的行动模式，动员钙储存在精子颈部区域。最后，我们考虑精子中钙信号通路的性质。我们认为，这种高度专业化和极端极化的细胞，虽然与体细胞相同的钙信号的“工具”，使用它们来产生不寻常的“硬连线”钙信号，不采取行动，以整合刺激。这些钙信号通路之间的“泄漏”将产生不适当的反应，损害细胞的功能。
Calcium signalling plays a pivotal role in sperm physiology, being intimately involved in the regulation of acrosome reaction, chemotaxis and hyperactivation. Here we describe briefly the mechanisms of calcium regulation in somatic cells and the ways in which these mechanisms have been adapted to function in mature spermatozoa. We then consider recent data from this and other laboratories on the responses of sperm to three compounds: progesterone and nitric oxide (both products of the cumulus oophorus) and 4-aminopyridine. All of these compounds induce calcium signals in the posterior sperm head and neck region and, when applied at appropriate concentrations, modify flagellar activity, causing asymmetric bending of the proximal flagellum. We argue that these effects reflect a common mode of action, mobilisation of calcium stored in the sperm neck region. Finally we consider the nature of calcium signalling pathways in sperm. We suggest that this highly specialised and extremely polarised cell, though working with the same calcium signalling 'tools' as those of somatic cells, employs them to generate unusually 'hard-wired' calcium signals that do not act to integrate stimuli. 'Leakage' between these calcium signalling pathways will generate inappropriate responses, compromising functioning of the cell.