Detweiler C, Thomas P
University of Texas Marine Science Institute, Port Aransas 78373, USA.
J Exp Zool. 1998 Jun 1;281(2):139-48.
The effects of the osmolarity and ionic composition of the external media and ion-channel blockers on the induction of sperm motility in the marine teleost, Atlantic croaker (Micropogonias undulatus) were investigated. An in vitro sperm motility assay was developed to determine treatment effects on the percentage of motile sperm, sperm speed, and turning rate, using a computer-aided motion-analysis system. Maximum activation of sperm motility occurred in saline with an osmolarity of 680 mOs/kg. Potassium caused a decrease in the percentage of motile sperm, but only at high nonphysiological concentrations in the presence of high amounts of calcium. Calcium caused an increase in sperm velocity and turning rate. Percent motility was inhibited by the potassium-channel blockers, 4-aminopyridine and veratrine, the calcium-channel blockers, verapamil, diltiazem, and nifedipine; the sodium-channel blocker, amiloride, and the chloride-channel blocker, ethacrynic acid. In addition, the calcium-channel blockers caused a decrease in sperm velocity and turning rate. These results provide evidence for the role of potassium, calcium, and possibly sodium, and chloride ions in Atlantic croaker sperm motility. In addition, this study demonstrates that membrane-bound ion channels are involved in the motility of sperm from a marine teleost.
研究了外部介质的渗透压和离子组成以及离子通道阻滞剂对海洋硬骨鱼大西洋黄鱼（Micropogonias undulatus）精子运动诱导的影响。开发了一种体外精子运动分析方法，使用计算机辅助运动分析系统来确定处理对活动精子百分比、精子速度和转弯率的影响。精子运动的最大激活发生在渗透压为680 mOs/kg的盐溶液中。钾会导致活动精子百分比下降，但仅在高浓度非生理浓度且存在大量钙的情况下。钙会导致精子速度和转弯率增加。活动百分比受到钾通道阻滞剂4-氨基吡啶和藜芦碱、钙通道阻滞剂维拉帕米、地尔硫卓和硝苯地平、钠通道阻滞剂阿米洛利以及氯通道阻滞剂依他尼酸的抑制。此外，钙通道阻滞剂会导致精子速度和转弯率下降。这些结果为钾、钙以及可能的钠和氯离子在大西洋黄鱼精子运动中的作用提供了证据。此外，本研究表明膜结合离子通道参与了海洋硬骨鱼精子的运动。
