Connor W E, Weleber R G, DeFrancesco C, Lin D S, Wolf D P
Department of Medicine, Oregon Health Sciences University, Portland 97201-3098, USA.
Invest Ophthalmol Vis Sci. 1997 Nov;38(12):2619-28.
To determine the fatty acid composition of erythrocytes and sperm, along with the functional characteristics of sperm, in patients with retinitis pigmentosa. Sperm and retinal cells share important homologies. Both are rich in the highly polyunsaturated fatty acid, docosahexaenoic acid (DHA, 22:6[n-3]), and both contain a structural component called the axoneme. Low concentrations of DHA in the retina of monkeys are known to cause visual impairment. Because blood levels of DHA in retinitis pigmentosa patients are less than normal, reduced DHA in the retina might contribute to the visual impairment characteristic of this disease. This study was conducted on the hypothesis that the sperm of retinitis pigmentosa patients might be abnormal and that these abnormalities might infer similar lipid and structural abnormalities of the retina.
The lipid composition of erythrocytes and sperm (fatty acids and sterols) and sperm function were analyzed in 26 patients with retinitis pigmentosa and in 8 healthy men.
The sperm of patients with retinitis pigmentosa had a much lower DHA concentration, a lower desmosterol-to-cholesterol ratio, reduced motility, abnormal structure, and lower sperm counts compared with that in normal subjects. Usher's II patients exhibited the most pronounced reductions of DHA in sperm. Sperm DHA concentration was positively correlated to sperm motility, to sperm count, and to the desmosterol-to-cholesterol ratio. Lower erythrocyte DHA was also observed in retinitis pigmentosa patients.
These results indicate that the sperm of patients with retinitis pigmentosa, particularly those with Usher's II, have an abnormal lipid composition that is associated with reduced motility. The possibility exists that these patients might have similar abnormalities in the DHA biochemistry of the retina. Sperm biochemistry and function may be a marker for this disease. A clinical trial of DHA in retinitis pigmentosa is suggested for future study.
确定色素性视网膜炎患者红细胞和精子的脂肪酸组成以及精子的功能特性。精子和视网膜细胞具有重要的同源性。二者都富含高度多不饱和脂肪酸二十二碳六烯酸（DHA，22:6[n-3]），且都含有一种称为轴丝的结构成分。已知猴子视网膜中DHA浓度低会导致视力损害。由于色素性视网膜炎患者血液中的DHA水平低于正常水平，视网膜中DHA减少可能导致该疾病的特征性视力损害。本研究基于以下假设开展：色素性视网膜炎患者的精子可能异常，且这些异常可能意味着视网膜存在类似的脂质和结构异常。
分析了26例色素性视网膜炎患者和8名健康男性的红细胞和精子的脂质组成（脂肪酸和甾醇）以及精子功能。
与正常受试者相比，色素性视网膜炎患者的精子DHA浓度低得多，胆甾烯醇与胆固醇的比例低，活力降低，结构异常，精子数量减少。尤塞氏综合征II型患者的精子中DHA减少最为明显。精子DHA浓度与精子活力、精子数量以及胆甾烯醇与胆固醇的比例呈正相关。色素性视网膜炎患者的红细胞DHA水平也较低。
这些结果表明，色素性视网膜炎患者，尤其是尤塞氏综合征II型患者的精子脂质组成异常，这与活力降低有关。这些患者的视网膜DHA生物化学可能存在类似异常。精子生物化学和功能可能是该疾病的一个标志物。建议未来开展色素性视网膜炎患者补充DHA的临床试验。
