The mouse sperm glycine receptor/chloride channel: cellular localization and involvement in the acrosome reaction initiated by glycine.
The mouse sperm glycine receptor/chloride channel: cellular localization and involvement in the acrosome reaction initiated by glycine.
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DOI：
10.1002/j.1939-4640.2000.tb03281.x
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发表时间：
2000-01
影响因子：
--
通讯作者：
Yoko Sato;J. Son;S. Meizel
中科院分区：
文献类型：
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作者：
Yoko Sato;J. Son;S. Meizel
以前，我们报道，甘氨酸启动在体外顶体反应（AR）的猪和人精子的机制，包括甘氨酸受体/氯离子通道（GlyR），这种受体/通道所需的透明带启动AR。由于小鼠精子是受精研究中的重要工具，我们研究了甘氨酸是否启动小鼠精子AR以及精子GlyR是否参与该启动。甘氨酸（250 μ M至1 mM）启动获能小鼠精子的AR，但不启动非获能小鼠精子的AR。甘氨酸引发的AR显着抑制50 nM士的宁，神经元GlyR拮抗剂。神经元GlyR激动剂牛磺酸和β-丙氨酸在1 mM或5 mM时不启动AR。抗大鼠脊髓GlyR的单克隆抗体显著抑制甘氨酸启动的AR，但不抑制自发AR。用该单克隆抗体和后固定的活精子进行的间接免疫荧光定位研究检测到3种免疫反应模式，涉及顶体周围质膜的2个位点。这些模式如下：A型定位在覆盖前顶体区尖端的质膜上; B型定位在覆盖顶体赤道段后部和/或顶体反应精子中修饰赤道段后部的质膜上; C型定位包括A型和B型。A型和C型仅见于顶体完整的精子。在获能过程中，A型定位的精子数量增加。我们的研究结果表明，小鼠精子提供了一个很好的模型，研究GlyR在顶体反应中的作用。
Previously, we reported that glycine initiates the in vitro acrosome reaction (AR) of porcine and human sperm by a mechanism that includes the glycine receptor/Cl- channel (GlyR) and that this receptor/channel is required for the zona-pellucida-initiated AR. Because mouse sperm are important tools in the study of fertilization, we investigated whether glycine initiated the mouse sperm AR and whether the sperm GlyR was involved in that initiation. Glycine (250 microM to 1 mM) initiated the AR of capacitated but not noncapacitated mouse sperm. The glycine-initiated AR was significantly inhibited by 50 nM strychnine, a neuronal GlyR antagonist. The neuronal GlyR agonists taurine and beta-alanine did not initiate the AR at 1 mM or 5 mM. A monoclonal antibody against the rat spinal cord GlyR significantly inhibited the glycine-initiated AR but not the spontaneous AR. Indirect immunofluorescence localization studies with that monoclonal antibody and postfixed live sperm detected 3 patterns of immunoreactivity involving 2 sites in the periacrosomal plasma membrane. These patterns were as follows: type A localization on the plasma membrane overlying the tip of the anterior acrosomal region; type B localization on the plasma membrane overlying the posterior part of the acrosomal equatorial segment and/or, in acrosome-reacted sperm, the posterior part of the modified equatorial segment; and type C localization that included both type A and type B. Type A and type C localization were only observed on the acrosome-intact sperm. During capacitation, the number of the sperm showing type A localization increased. Our results demonstrate that mouse sperm provide an excellent model for studying the role of the GlyR in the acrosome reaction.