dl-扁桃酸对精子质膜及顶体的完整性和线粒体膜电位的影响

Effect of dl-mandelic acid on sperm acrosome and mitochondrial membrane potential

目的：研究dl-扁桃酸（dl-mandelic acid）的抑精作用及其机制。方法：dl-扁桃酸0.5-10.0g·L^-1处理高活力精子20 s,计算机辅助精子分析仪（computer assistant spermanalysis,CASA）测定精子活率、精子直线运动速率（VSL）、曲线运动速率（VCL）、平均路径速率（VAP）、侧摆幅度（ALH）、精子运动向前性（STR）和精子运动直线性（LIN）;流式细胞（SYBR-14/PI）检测精子质膜完整性,采用FITC标记的豌豆凝集素荧光染色观察精子顶体完整性;FITC-PSA/PI/JC-1荧光染色检测精子线粒体膜电位变化。结果：随着dl-扁桃酸浓度的升高,精子活率与精子直线运动速率（VSL）、曲线运动速率（VCL）、平均路径速率（VAP）、侧摆幅度（ALH）、精子运动向前性（STR）和精子运动直线性（LIN）显著降低,dl-扁桃酸抑制精子活率的半数有效浓度（EC50）约为1.25 g·L^-1,最低有效浓度（MEC）约为2.5 g·L^-1。流式细胞仪检测表明,dl-扁桃酸对精子质膜完整性无影响。荧光染色检测表明,dl-扁桃酸处理组精子顶体受损,精子线粒体膜电位降低。结论：dl-扁桃酸通过影响精子顶体和降低线粒体膜电位,对精子起到抑制作用。

Objective： To investigate the sperm motility-inhibiting effect of dl-mandelic acid and its possible mechanism. Methods： The high vigor sperm was incubated with dl-mandelic acid（ 0. 5 - 10. 0 g·L^-1） for 20 seconds. The survival rate and straight line velocity（ VSL）,curvilinear velocity（ VCL）,average path velocity（ VAP）,amplitude of lateral head displacement（ ALH）,and straightness（ STR） linearity（ LIN） of sperm were evaluated by CASA（ computer assistant spermanalysis）. The integrity of sperm plasma membrane was detected by flow cytometry. The integrity of sperm acrosome and flagella was detected with FITC-PSA / CY3-antitubulin double immunofluorescence staining. The damage to plasma membrane and membrane potential was detected with FITCPSA / PI / JC-1 treble immunofluorescence staining. Results： The sperm survival rate,and VSL,VCL,VAP,ALH,STR and LIN gradually reduced with the increase of the concentration of dl-mandelic acid. The median effective concentration（ EC50） was 1. 25 g·L^-1,and the minimal effective concentration（ MEC） was 2. 5 g·L^-1. Results offlow cytometry showed that dl-mandelic acid did not destroy the sperm plasma membrane. Results of FITC-PSA staining and FITC-PSA / PI / JC-1 staining showed that the sperm acrosome was destroyed by dl-mandelic acid,and the sperm mitochondrial membrane potential was reduced. Conclusion： dl-Mandelic acid inhibits sperm motility through affecting sperm acrosome and mitochondrial membrane potential.