Breitbart H, Nass-Arden L
Department of Life Sciences, Bar-Ilan University, Ramat Gan, Israel.
Arch Androl. 1995 Sep-Oct;35(2):83-92. doi: 10.3109/01485019508987858.
Collective sperm motility is characterized in terms of periodic aggregation or cooperation among cells, which are seen under a microscope as a continuous wave motion. In this study, sperm motility that was made dependent on mitochondrial activity (glycolysis inhibited) was significantly inhibited by mM exogenous calcium while glycolytic-dependent (mitochondrial respiration inhibited) motility was not inhibited under these conditions. At intracellular Ca2+ above 400 nM, sperm motility was inhibited independently of the source of ATP. At [Ca2+]i of approximately 110 nM, mitochondrial- or glycomitochondrial-dependent motility showed 75 or 0% inhibition, respectively, indicating higher sensitivity of mitochondrial-dependent motility to [Ca2+]i in comparison to glycolytic-dependent motility. Under the latter conditions, intracellular level of ATP was reduced by 16% only, indicating that the 75% inhibition of mitochondrial-dependent motility was not due to reduction in ATP. The inhibition of mitochondrial-dependent motility by mM extracellular Ca2+ can be prevented by incubating the cells at pH 6.5 instead of 7.6. At pH 7.6, calcium probably interacts with negative sites on the cell surface and interferes in cell-to-cell interactions, which are important to achieve collective motility. At more acidic pH (6.5) these negative sites are probably protonated; thus Ca2+ cannot interact with them and no inhibition of motility could be seen. Glycolytic-dependent motility was not inhibited by extracellular Ca2+, since the pH of the medium becomes acidic under these conditions. Like Ca2+, mersalyl, which interacts with Ca2+ binding sites on the cell surface, showed significant inhibition of mitochondrial-dependent motility without any effect on glycolytic-dependent motility. Collective motility was directly correlated with fertility. These data are significant for establishing better conditions for spermatozoa treatment when artificial insemination or in vitro fertilization is concerned.
集体精子活力的特征在于细胞之间的周期性聚集或协作，在显微镜下可观察到这种现象呈现为连续的波动运动。在本研究中，依赖线粒体活性（糖酵解被抑制）的精子活力在存在毫摩尔浓度的外源钙时受到显著抑制，而依赖糖酵解（线粒体呼吸被抑制）的活力在这些条件下未受抑制。当细胞内钙离子浓度高于400 nM时，精子活力受到抑制，且与ATP来源无关。在细胞内钙离子浓度约为110 nM时，依赖线粒体或糖酵解 - 线粒体的活力分别显示出75%或0%的抑制，这表明与依赖糖酵解的活力相比，依赖线粒体的活力对细胞内钙离子浓度更为敏感。在后一种条件下，细胞内ATP水平仅降低了16%，这表明依赖线粒体的活力75%的抑制并非由于ATP减少所致。通过将细胞在pH 6.5而非7.6的条件下孵育，可以防止毫摩尔浓度的细胞外钙对依赖线粒体的活力的抑制作用。在pH 7.6时，钙可能与细胞表面的负性位点相互作用，并干扰细胞间相互作用，而细胞间相互作用对于实现集体活力很重要。在更酸性的pH（6.5）条件下，这些负性位点可能被质子化；因此钙离子无法与它们相互作用，且未观察到活力受到抑制。依赖糖酵解的活力不受细胞外钙的抑制，因为在这些条件下培养基的pH会变为酸性。与钙一样，与细胞表面钙结合位点相互作用的汞撒利对依赖线粒体的活力显示出显著抑制，而对依赖糖酵解的活力没有任何影响。集体活力与生育能力直接相关。当涉及人工授精或体外受精时，这些数据对于建立更好的精子处理条件具有重要意义。
