Keskes L, Giroux-Widemann V, Serres C, Pignot-Paintrand I, Jouannet P, Feneux D
Laboratoire de Biologie de la Reproduction, Université Paris V, Hopital Cochin-Port-Royal, France.
Mol Reprod Dev. 1998 Apr;49(4):416-25. doi: 10.1002/(SICI)1098-2795(199804)49:4<416::AID-MRD9>3.0.CO;2-Q.
The effect of pH, Mg-ATP, and free calcium on activity of the inner dynein arm was investigated using demembranated human spermatozoa lacking the outer dynein arms (LODA). The results were compared with those obtained for demembranated-reactivated normal spermatozoa to evaluate the functional properties of the inner and outer dynein arms in axonemal motility. The reactivation of Triton X-100-demembranated LODA spermatozoa was analysed at various pHs and concentrations of Mg-ATP and calcium using video recordings. The percentage of reactivated LODA spermatozoa as a function of Mg-ATP concentration was not dependent on pH, whereas reactivation of normal human spermatozoa is pH dependent. This suggests that there may be a pH-dependent regulatory mechanism associated with the outer dynein arms. A delay in the principal bend propagation of normal and LODA reactivated cells was found at pH 7.1. This disappeared at pH 7.8 in normal but not in LODA populations. This suggests a role for outer dynein arms in the initiation of the propagation of flagellar bends at alkaline pH. The level of LODA and normal sperm reactivation both depended on the calcium concentration in the medium. At lower free calcium concentrations, the reactivation level and beat frequency of reactivated cells were higher. Our results suggest a functional difference between outer and inner dynein arms of human spermatozoa based on a differential pH sensitivity. Moreover, calcium seems to exert its regulatory action elsewhere than on the outer dynein arms.
利用缺乏外动力蛋白臂（LODA）的去膜人精子，研究了pH值、Mg-ATP和游离钙对内动力蛋白臂活性的影响。将结果与去膜再激活的正常精子所获得的结果进行比较，以评估内、外动力蛋白臂在轴丝运动中的功能特性。使用视频记录分析了在不同pH值、Mg-ATP和钙浓度下，经Triton X-100去膜的LODA精子的再激活情况。再激活的LODA精子百分比作为Mg-ATP浓度的函数并不依赖于pH值，而正常人精子的再激活则依赖于pH值。这表明可能存在一种与外动力蛋白臂相关的pH依赖性调节机制。在pH 7.1时，正常和LODA再激活细胞的主弯曲传播出现延迟。在pH 7.8时，这种延迟在正常细胞中消失，但在LODA群体中没有消失。这表明外动力蛋白臂在碱性pH值下鞭毛弯曲传播的起始中发挥作用。LODA和正常精子的再激活水平均取决于培养基中的钙浓度。在较低的游离钙浓度下，再激活细胞的再激活水平和摆动频率更高。我们的结果表明，基于不同的pH敏感性，人精子的外动力蛋白臂和内动力蛋白臂之间存在功能差异。此外，钙似乎在除外动力蛋白臂之外的其他地方发挥其调节作用。
