Tesarik J, Carreras A, Mendoza C
National Institute of Health and Medical Research (INSERM), Unit 355, Clamart, France.
Mol Reprod Dev. 1993 Feb;34(2):183-9. doi: 10.1002/mrd.1080340210.
Pertussis toxin-sensitive guanine nucleotide-binding regulatory proteins (G proteins) have previously been shown to mediate the zone pellucida-induced acrosome reaction in mammalian sperm. In this study we compared the inhibitory effect of pertussis toxin on the zona-induced acrosome reaction in human spermatozoa with that on the reaction induced by progesterone, another physiological acrosome reaction-promoting stimulus associated with the ovulated oocyte. Up to the concentration of 1 microgram/ml, pertussis toxin did not produce any direct effects on the acrosome reaction frequency nor did it influence sperm movement and viability. However, preincubation of spermatozoa with the toxin at a concentration of 100 ng/ml completely abolished the increase in the acrosome reaction frequency upon subsequent exposure to solubilized zona pellucida material. In contrast, the same treatment did not impair the ability of spermatozoa to initiate the acrosome reaction in response to progesterone. Moreover, the preincubation with pertussis toxin did not modify the changes in the intracellular concentration of calcium ions occurring after progesterone addition. These data suggest that different physiological stimuli may utilize different signal transduction pathways to induce the human sperm acrosome reaction.
百日咳毒素敏感的鸟嘌呤核苷酸结合调节蛋白（G蛋白）此前已被证明可介导哺乳动物精子中透明带诱导的顶体反应。在本研究中，我们比较了百日咳毒素对人精子中透明带诱导的顶体反应的抑制作用与对孕酮诱导的反应的抑制作用，孕酮是与排卵卵母细胞相关的另一种生理性顶体反应促进刺激物。在浓度高达1微克/毫升时，百日咳毒素对顶体反应频率没有任何直接影响，也不影响精子运动和活力。然而，将精子与浓度为100纳克/毫升的毒素预孵育，会完全消除随后暴露于溶解的透明带物质时顶体反应频率的增加。相比之下，相同处理不会损害精子对孕酮作出反应启动顶体反应的能力。此外，用百日咳毒素预孵育不会改变添加孕酮后细胞内钙离子浓度的变化。这些数据表明，不同的生理刺激可能利用不同的信号转导途径来诱导人精子顶体反应。
