Balercia Giancarlo, Moretti Simona, Vignini Arianna, Magagnini Mattia, Mantero Franco, Boscaro Marco, Ricciardo-Lamonica Giuseppe, Mazzanti Laura
Endocrinology Division, Department of Internal Medicine, University of Ancona, Ancona, Italy.
J Androl. 2004 Mar-Apr;25(2):245-9. doi: 10.1002/j.1939-4640.2004.tb02784.x.
Nitric oxide (NO) is a free radical generated from the oxidation of L-arginine to L-citrulline by 3 isoforms of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent NO synthases. Several data suggest a relevant role in sperm cell pathophysiology, but any conclusive data on its role in spermatozoa motility are still lacking. In the present study, we have correlated NO concentration in semen and kinetic features of sperm cells from normozoospermic fertile donors and infertile patients affected by idiopathic asthenozoospermia. Normozoospermic fertile men exhibited NO concentrations that were significantly lower than those of asthenozoospermic infertile men. A significant linear negative correlation was evident between NO concentration and percentage of total sperm motility. A further significant linear negative correlation was found between NO concentration and spermatozoa kinetic characteristics determined by a computerized analysis (curvilinear and straight progressive velocity). These data suggest that the overproduction of this free radical and the consequent excessive exposure to oxidative conditions have a potential pathogenetic implication in the reduction of sperm motility. The positive role played by NO in spermatozoa capacitation leads us to speculate that such paradoxical involvement in both pathologic and physiologic processes depends on the alternative redox state and relative level of NO.
一氧化氮（NO）是一种自由基，由还原型烟酰胺腺嘌呤二核苷酸磷酸（NADPH）依赖性一氧化氮合酶的3种同工型将L-精氨酸氧化为L-瓜氨酸而产生。多项数据表明其在精子细胞病理生理学中具有重要作用，但关于其在精子活力方面作用的确切数据仍然缺乏。在本研究中，我们将精液中NO浓度与正常精子生育力供体以及患有特发性弱精子症的不育患者精子细胞的动力学特征进行了关联。正常精子生育力男性的NO浓度显著低于弱精子症不育男性。NO浓度与总精子活力百分比之间存在明显的线性负相关。通过计算机分析确定的NO浓度与精子动力学特征（曲线和直线前进速度）之间还存在进一步的显著线性负相关。这些数据表明，这种自由基的过度产生以及随之而来的过度暴露于氧化条件在精子活力降低方面具有潜在的致病意义。NO在精子获能中所起的积极作用使我们推测，这种在病理和生理过程中的矛盾参与取决于NO的替代氧化还原状态和相对水平。
