KATP channels in mouse spermatogenic cells and sperm, and their role in capacitation
KATP channels in mouse spermatogenic cells and sperm, and their role in capacitation
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DOI：
10.1016/j.ydbio.2005.11.002
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发表时间：
2006-01-15
影响因子：
2.7
通讯作者：
Darszon, A
中科院分区：
文献类型：
--
作者：
Acevedo, JJ;Mendoza-Lujambio, I;Darszon, A
哺乳动物精子离开睾丸后必须经历一系列生理变化才能受精。这些变化统称为获能，发生在雌性生殖道，精子质膜在其成分和离子渗透性方面发生变化。在其他事件中，小鼠精子获能导致细胞内Ca 2+和pH值的增加以及膜电位的超极化。众所周知，离子通道在这些事件中起着至关重要的作用，尽管参与获能的特定通道的分子身份还不清楚。本文报道了K-ATP通道在小鼠生精细胞和精子中的鉴定及其功能。用全细胞膜片钳技术记录小鼠生精细胞的K+内向整流（K-ir）电流，发现该电流对Ba ~（2+）、葡萄糖和磺酰脲类药物（甲苯磺丁脲和格列本脲）敏感。使用ATP合成抑制剂和K-ATP通道激活剂证实了这些通道的存在。此外，RT-PCR检测允许我们检测转录的K-ATP亚基SUR 1，SUR 2，K（ir）6.1和K（ir）6.2的总RNA从延长精子细胞。此外，免疫共聚焦显微镜显示，这些K-ATP亚基在小鼠生精细胞和精子的存在。值得注意的是，在获能过程中与甲苯磺丁脲孵育的精子取消超极化，并以剂量依赖性方式显着降低AR的百分比。总之，我们的研究结果提供了证据，在小鼠生精细胞和精子的K-ATP通道的存在，并披露这些通道的获能相关的超极化的贡献。(c)2005年爱思唯尔公司All rights reserved.
Mammalian sperm must undergo a series of physiological changes after leaving the testis to become competent for fertilization. These changes, collectively known as capacitation, occur in the female reproductive tract where the sperm plasma membrane is modified in terms of its components and ionic permeability. Among other events, mouse sperm capacitation leads to an increase in the intracellular Ca2+ and pH as well as to a hyperpolarization of the membrane potential. It is well known that ion channels play a crucial role in these events, though the molecular identity of the particular channels involved in capacitation is poorly defined. In the present work, we report the identification and potential functional role of K-ATP channels in mouse spermatogenic cells and sperm. By using whole-cell patch clamp recordings in mouse spermatogenic cells, we found K+ inwardly rectifying (K-ir) currents that are sensitive to Ba2+, glucose and the sulfonylureas (tolbutamide and glibenclamide) that block K-ATP channels. The presence of these channels was confirmed using inhibitors of the ATP synthesis and K-ATP channel activators. Furthermore, RT-PCR assays allowed us to detect transcripts for the K-ATP subunits SUR1, SUR2, K(ir)6.1 and K(ir)6.2 in total RNA from elongated spermatids. In addition, immunoconfocal microscopy revealed the presence of these K-ATP subunits in mouse spermatogenic cells and sperm. Notably, incubation of sperm with tolbutamide during capacitation abolished hyperpolarization and significantly decreased the percentage of AR in a dose-dependent fashion. Together, our results provide evidence for the presence of K-ATP channels in mouse spermatogenic cells and sperm and disclose the contribution of these channels to the capacitation-associated hyperpolarization. (c) 2005 Elsevier Inc. All rights reserved.