Hoffman D R, Uauy R, Birch D G
Retina Foundation of the Southwest, Dallas, TX 75231, USA.
Exp Eye Res. 1995 Mar;60(3):279-89. doi: 10.1016/s0014-4835(05)80110-1.
Abnormalities in lipid metabolism have been reported in numerous patients with retinitis pigmentosa. As an initial step in evaluating these anomalies, two trials of fatty acid intervention were conducted with autosomal dominant retinitis pigmentosa (adRP) patients and controls. The first trial addressed absorption and incorporation of omega 3 long-chain fatty acids from a fish-oil concentrate into red blood cell (RBC) lipids. The utilization of omega 3 long-chain fatty acids by adRP patients was found to be equivalent to that of controls. The second trial addressed the conversion of precursor, eicosapentaenoic acid (EPA, 20:5 omega 3), to end-product, docosahexaenoic acid (DHA, 22:6 omega 3), following oral supplementation of EPA ethyl ester. Although the levels of EPA and the intermediate, docosapentaenoic acid (22:5 omega 3), were both elevated by EPA supplementation in RBCs of adRP patients with rhodopsin gene mutations and controls, DHA production was elevated only in controls. Based on these results, we suggest the presence of a metabolic defect in the final stages of DHA biosynthesis.
众多视网膜色素变性患者都有脂质代谢异常的报道。作为评估这些异常情况的第一步，对常染色体显性视网膜色素变性（adRP）患者和对照组进行了两项脂肪酸干预试验。第一项试验研究了鱼油浓缩物中的ω-3长链脂肪酸在红细胞（RBC）脂质中的吸收和掺入情况。发现adRP患者对ω-3长链脂肪酸的利用率与对照组相当。第二项试验研究了口服补充二十碳五烯酸乙酯（EPA，20:5 ω-3）后，前体物质二十碳五烯酸（EPA）向终产物二十二碳六烯酸（DHA，22:6 ω-3）的转化情况。尽管在视紫红质基因突变的adRP患者和对照组的红细胞中，补充EPA后EPA和中间产物二十二碳五烯酸（22:5 ω-3）的水平均有所升高，但DHA的生成仅在对照组中升高。基于这些结果，我们认为在DHA生物合成的最后阶段存在代谢缺陷。
