Bize I, Santander G, Cabello P, Driscoll D, Sharpe C
Embryology Laboratory, Faculty of Biological Sciences, Pontifical Catholic University, Santiago, Chile.
Biol Reprod. 1991 Mar;44(3):398-403. doi: 10.1095/biolreprod44.3.398.
We have investigated the possibility that the generation of hydrogen peroxide (H2O2) by spermatozoa plays a physiological role during capacitation. Capacitation is defined as the incubation period required for fertilization in mammals. Capacitation culminates in an exocytotic event, the acrosome reaction (AR). Mammalian sperm generate H2O2 during aerobic incubation and do not contain catalase, the enzyme that promotes scavenging of H2O2. In the present work we show that added catalase inhibited the AR, while glucose oxidase (GO), an enzyme that generates H2O2, accelerated the onset of the AR. Direct addition of H2O2 also stimulated the AR; catalase inhibited both the stimulation by GO and by H2O2. The onset of the AR was always preceded by the appearance of hyperactivated motility. The stimulation of the AR by H2O2 was manifest 1-2 h after the addition of H2O2. Catalase added at 3 h of incubation was less effective in inhibiting the AR than catalase added at the beginning. Incubation of sperm with catalase prevented the induction of the AR by the membrane-perturbing lipid, lysophosphatidyl choline. Taken together, these results suggest that H2O2 produced by hamster sperm plays a significant role during capacitation, possibly in membrane reorganization to facilitate the fusion that takes place during exocytosis of the acrosomal contents.
我们已经研究了精子产生过氧化氢（H2O2）在获能过程中发挥生理作用的可能性。获能被定义为哺乳动物受精所需的潜伏期。获能最终导致一个胞吐事件，即顶体反应（AR）。哺乳动物精子在有氧孵育过程中会产生H2O2，并且不含有促进H2O2清除的过氧化氢酶。在本研究中，我们发现添加过氧化氢酶会抑制顶体反应，而葡萄糖氧化酶（GO），一种能产生H2O2的酶，则会加速顶体反应的开始。直接添加H2O2也会刺激顶体反应；过氧化氢酶既抑制了GO的刺激作用，也抑制了H2O2的刺激作用。顶体反应的开始总是先出现超活化运动。H2O2对顶体反应的刺激在添加H2O2后1 - 2小时显现出来。在孵育3小时时添加过氧化氢酶抑制顶体反应的效果不如在开始时添加的过氧化氢酶。用过氧化氢酶孵育精子可防止膜扰动脂质溶血磷脂酰胆碱诱导顶体反应。综上所述，这些结果表明仓鼠精子产生的H2O2在获能过程中发挥着重要作用，可能参与膜重组以促进顶体内容物胞吐过程中发生的融合。
