精液叶酸、维生素B_(12)、活性氧水平与精子质量关系研究

目的 :　检测人精液叶酸、维生素 B12 ( VB12 ) ,及活性氧 ( ROS)的含量 ,探讨三者与精子质量的关系。方法 :　收集经证实配偶已怀孕的新加坡籍健康成年男性 1 76名的精液 ,根据WHO推荐方法检测精子质量各项指标 ,并测定精液叶酸和 VB12 含量及 ROS水平。结果 :　平均精液量、精子浓度和其活力都在正常范围内。而精子存活率 ( 73.0 6% )略低于 WHO标准 (≥ 75% ) ,形态异常的精子 ( 77.0 6% )高于 WHO标准 ( 70 % )。精液的叶酸含量与 ROS水平呈显著负相关 ( r=- 0 .2 5,P=0 .0 0 3) ;VB12 与 ROS呈负相关 ( r=- 0 .2 5,P=0 .0 0 2 ) ,与精子形态异常也呈负相关( r=- 0 .1 5,P=0 .0 4 8) ,但与精子浓度呈正相关 ( r=0 .31 ,P<0 .0 0 1 )。ROS与精子形态异常呈正相关 ( r=0 .2 5,P=0 .0 0 2 ) ,与精子活力也呈正相关 ( r=0 .1 9,P=0 .0 1 9)。结论 :　 VB12 对精子生成和维持精子正常功能是必需的 ,ROS水平与精子功能缺陷有关 ,VB12 和叶酸可能通过降低 ROS以维持精子的正常功能。

SEMINAL FOLATE, VITAMIN B12 AND REACTIVE OXYGEN SPECIES, AND THEIR RELATIONSHIPS WITH SPERM PARAMETERS

Objective: To measure the concentrations of folate, vitamin B 12 (VB 12 ),and the levels of reactive oxygen speciees (ROS) in whole semen, and to determine their relationships with various sperm parameters. Methods: The semen from 176 healthy fertile men were collected and analyzed according to WHO guidelines. The concentrations of folate and VB 12 as well as levels of ROS were determined.Results: The means of sperm volume, density, and motility for the study population were generally within the normal range of WHO criteria for sperm parameters. The mean concentrations of folate and VB 12 were 20.09 nmol/L and 667.73 pmol/L respectively. The mean level of ROS was 71631 RLU/5 minutes. The concentration of VB 12 showed a significantly positive relationship with sperm density (r=0.31,P<0.001). A statistically negative relationship was noted between VB 12 and the percentage of morphological defective sperm(r=-0.15,P=0.048).VB 12 also showed an inverse correlation with the level of ROS(r=-0.25,P=0.002).There was a significantly negative correlation between the concentration of folate and the levels of ROS (R=-0.25,P=0.003).The level of ROS showed a significantly positive correlation with sperm motility (r=0.19,P=0.019) and with the percentage of morphological defective sperm (r=0.25,P= 0.002 ). Conclusion: VB 12 is essential for spermatogenesis and maintenance of normal sperm functions. The level of ROS is closely associated with the morphological defect of sperm. Both folate and VB 12 are important for normal sperm functions, perhaps by reducing semen ROS.