Zalata A A, Christophe A B, Depuydt C E, Schoonjans F, Comhaire F H
University Hospital Ghent, Department of Internal Medicine, Belgium.
Mol Hum Reprod. 1998 Feb;4(2):111-8. doi: 10.1093/molehr/4.2.111.
The lipid composition of the sperm membrane has a significant effect upon the functional characteristics of spermatozoa. In the present study we investigated the fatty acid (FA) composition of subpopulations of spermatozoa separated on a discontinuous Percoll gradient (47:90%) and the FA composition of phospholipids (PL) of sperm heads and tails in both normal and abnormal semen samples. In normozoospermic samples, polyunsaturated fatty acids (PUFA) represented 34.0 +/- 1.3 (mean +/- SE, mole %) and 25.6 +/- 1.2% of total FA of PL of the 47 and 90% Percoll fractions respectively. Docosahexaenoic acid (22:6omega3, DHA) contributed to more than 60% of total PUFA. DHA was significantly lower in both the 47% (P < 0.05) and the 90% (P < 0.01) Percoll fractions of oligozoospermic samples and in the 90% Percoll layer of asthenozoospermic samples (P < 0.01), compared with normozoospermic samples. The omega6/omega3 ratio was significantly increased in both Percoll fractions of samples with oligozoospermia (47%, P < 0.001 and 90%, P < 0.001) or with asthenozoospermia (47%, P < 0.05 and 90%, P < 0.001) compared with normozoospermic samples. The oxidative potential index (OPI) of spermatozoa recovered from the 47% Percoll layer was significantly higher (P < 0.0001) than of those recovered from the 90% Percoll. Mean melting point (MMP), an index of membrane fluidity, was significantly lower in head than in tails (P < 0.01) of spermatozoa, and also in both the 47% (P < 0.01) and 90% (P < 0.001) Percoll fractions of normozoospermic samples in comparison with oligozoospermic samples. The MMP was significantly higher (P < 0.05) in samples of patients with idiopathic oligo/asthenozoospermia, varicocele, and male accessory gland infection (MAGI). These differences in FA composition of PL in subpopulations of human spermatozoa, and in their heads and tails may be related to sperm maturity and to differences in physiological function.
精子膜的脂质组成对精子的功能特性有显著影响。在本研究中，我们调查了通过不连续Percoll梯度（47:90%）分离的精子亚群的脂肪酸（FA）组成，以及正常和异常精液样本中精子头部和尾部磷脂（PL）的FA组成。在正常精子样本中，多不饱和脂肪酸（PUFA）分别占47%和90% Percoll组分中PL总FA的34.0±1.3（平均值±标准误，摩尔%）和25.6±1.2%。二十二碳六烯酸（22:6ω3，DHA）占总PUFA的60%以上。与正常精子样本相比，少精子症样本的47%（P<0.05）和90%（P<0.01）Percoll组分以及弱精子症样本的90% Percoll层中DHA均显著降低（P<0.01）。少精子症（47%，P<0.001和90%，P<0.001）或弱精子症（47%，P<0.05和90%，P<0.001）样本的两个Percoll组分中的ω6/ω3比值均显著高于正常精子样本。从47% Percoll层回收的精子的氧化电位指数（OPI）显著高于从90% Percoll层回收的精子（P<0.0001）。平均熔点（MMP）是膜流动性的一个指标，精子头部的MMP显著低于尾部（P<0.01），与少精子症样本相比，正常精子样本的47%（P<0.01）和90%（P<0.001）Percoll组分中的MMP也显著更低。特发性少/弱精子症、精索静脉曲张和男性附属腺感染（MAGI）患者样本中的MMP显著更高（P<0.05）。人类精子亚群及其头部和尾部PL的FA组成的这些差异可能与精子成熟度和生理功能差异有关。
