Bazan H E, Bazan N G, Feeney-Burns L, Berman E R
Louisiana State University Eye Center, New Orleans 70112.
Invest Ophthalmol Vis Sci. 1990 Aug;31(8):1433-43.
The fatty acid composition and content of total phospholipids, free fatty acids (FFA), diacylglycerols (DG), phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE) were studied in lipofuscin granules of human donors in two age groups, young (less than 40 yr old) and old (more than 47 yr old), and compared with lipids of the photoreceptor rod outer segments (ROS). Neural retina (NR) and retinal pigment epithelium (RPE) also were studied. In both age groups, the lipid composition of the lipofuscin granules differed from that of the ROS, with a decrease in the proportion of phospholipid and an increase in FFA, suggesting very high phospholipase activity in the lipofuscin granules. In ROS, docosahexaenoic acid (22:6) was the predominant FFA, whereas palmitic acid (16:0), arachidonic acid (20:4) and oleic acid (18:1) were the major fatty acids in the lipofuscin granules. The fatty acid compositions of PC, PE, and PS of lipofuscin granules were different from those of the retina. There was proportionally less 22:6 in lipofuscin, and the amounts of saturated and monounsaturated fatty acyl chains such as 16:0, stearate (18:0), and 18:1 were greater than in retina. Compared to ROS, the lipofuscin granules showed a significant decrease in DG containing 20:4 but not 22:6. With aging, there was a decrease in the amount of total polyunsaturated fatty acyl chains (22:6 and 20:4) in the lipofuscin granules. These results show that the lipid composition of lipofuscin is different from that of ingested ROS, probably because of increased phospholipase and peroxidative activities in lipofuscin, directed toward ingested ROS as well as toward other materials from the RPE and blood.
研究了两个年龄组（年轻组，小于40岁；老年组，大于47岁）人类供体脂褐素颗粒中总磷脂、游离脂肪酸（FFA）、二酰基甘油（DG）、磷脂酰胆碱（PC）、磷脂酰丝氨酸（PS）和磷脂酰乙醇胺（PE）的脂肪酸组成和含量，并与光感受器视杆细胞外段（ROS）的脂质进行了比较。还研究了神经视网膜（NR）和视网膜色素上皮（RPE）。在两个年龄组中，脂褐素颗粒的脂质组成与ROS不同，磷脂比例降低，FFA增加，提示脂褐素颗粒中磷脂酶活性非常高。在ROS中，二十二碳六烯酸（22:6）是主要的FFA，而棕榈酸（16:0）、花生四烯酸（20:4）和油酸（18:1）是脂褐素颗粒中的主要脂肪酸。脂褐素颗粒中PC、PE和PS的脂肪酸组成与视网膜不同。脂褐素中22:6的比例相对较少，饱和和单不饱和脂肪酰链如16:0、硬脂酸（18:0）和18:1的含量高于视网膜。与ROS相比，脂褐素颗粒中含20:4但不含22:6的DG显著减少。随着年龄增长，脂褐素颗粒中总多不饱和脂肪酰链（22:6和20:4）的含量减少。这些结果表明，脂褐素的脂质组成与摄入的ROS不同，可能是因为脂褐素中磷脂酶和过氧化活性增加，这不仅针对摄入的ROS，也针对来自RPE和血液的其他物质。
