BICARBONATE - CARBON-DIOXIDE REGULATION OF SPERM CAPACITATION, HYPERACTIVATED MOTILITY, AND ACROSOME REACTIONS
BICARBONATE - CARBON-DIOXIDE REGULATION OF SPERM CAPACITATION, HYPERACTIVATED MOTILITY, AND ACROSOME REACTIONS
复制标题
DOI：
10.1095/biolreprod44.5.806
复制
发表时间：
1991-05-01
影响因子：
3.6
通讯作者：
ROBBINS, RS
中科院分区：
文献类型：
--
作者：
BOATMAN, DE;ROBBINS, RS
研究了碳酸氢钠：二氧化碳(HCO3-：CO2)浓度对金黄地鼠精子活力、自发性顶体反应和顶体穿透性(用于检测顶体反应)的依赖关系。采用交叉试验设计，将获能早期(孵化前5h)与后1h对顶体反应和顶体穿透的影响分开，5h后，HCO3-：CO2浓度增加、降低或在1h内保持不变，与无HCO3-：CO2相比，仅2.9 mM：0.6%HCO3-：CO2可使精子活力指数(MI)提高2.7-3.6倍。当HCO3-：CO2持续存在时，HCO3-：CO2以剂量依赖的方式在获能完成前3-4h刺激前进运动和过度激活的运动。在获能后期1h向精子中添加HCO3-：CO2对顶体反应或穿透透明带的刺激作用主要取决于获能较早的HCO3-：CO2水平。仅在5h加入25 mM：5%HCO3-：CO2时，精子的反应性明显低于用相同浓度HCO3-：CO2连续处理的精子，MI降低2.5倍，顶体反应降低2倍，穿透性降低6.3倍。相反，在5小时后将HCO3-：CO2降低到次佳水平并不会显著降低任何6小时的精子反应。所有反应的平均最大和一半最大预孵化HCO3-浓度分别为34.2+/-1.0和9.2+/-0.3 mM。透明带穿透与过度激活高度相关。我们的结论是：1)HCO3-：CO2主要通过刺激精子的运动和获能早期阶段来影响精子的受精能力；2)顶体反应，无论是由透明带诱导的还是自发的，都只受到次要的影响。
The bicarbonate: CO2 (HCO3-:CO2) concentration dependencies of hamster sperm motility, spontaneous acrosome reactions, and zona penetration (used to assay the zona-induced acrosome reaction) were examined. A cross-over experimental design was used to segregate effects on early stages of capacitation, spanning the first 5 h of incubation, from those on acrosome reactions and zona penetration during the last 1 h. After 5 h, HCO3-:CO2 concentrations were increased, decreased, or kept the same for 1 h. Compared to no HCO3-:CO2, as little as 2.9 mM:0.6% HCO3-:CO2 increased the sperm motility index (MI) by 2.7-3.6 times. When HCO3-:CO2 was continuously present, both progressive and hyperactivated motility were stimulated by HCO3-:CO2 in a dose-dependent manner by 3-4 h, well before completion of capacitation. Stimulation of acrosome reactions or zona penetration, by addition of HCO3-:CO2 to sperm for 1 h late in capacitation, depended mainly on levels of HCO3-:CO2 present earlier in capacitation. When 25 mM:5% HCO3-:CO2 was added only at 5 h, responses were significantly lower than with sperm treated continuously with the same concentration of HCO3-:CO2, being 2.5 times lower for MI, 2 times lower for acrosome reactions, and 6.3 times lower for zona penetration. In contrast, decreasing HCO3-:CO2 to suboptimal levels after 5 h did not decrease any 6-h sperm responses significantly. The average maximal and one-half maximal preincubation HCO3- concentrations for all responses were 34.2 +/- 1.0 and 9.2 +/- 0.3 mM, respectively. Zona penetration and hyperactivation were highly correlated. We conclude that 1) HCO3-:CO2 mainly affects sperm fertilizing ability by stimulating both motility and earlier stages of capacitation and that 2) acrosome reactions, either zona-induced or spontaneous, are only secondarily affected.