Sohal R S, Bridges R G, Howes E A
Mech Ageing Dev. 1984 Jun;25(3):355-63. doi: 10.1016/0047-6374(84)90009-5.
The fractional volume occupied by lipofuscin granules in epithelial cells of the midgut or oenocytes of abdominal fat body of 3-day-old and 13-day-old male houseflies was determined in two groups of flies by electron microscopic morphometry. One group had developed from larvae reared on diets containing no added polyunsaturated fatty acids and the second from larvae reared on diets containing added linoleic acid. No polyunsaturated fatty acids could be detected in the lipids of the first group of flies using a method which would have detected their presence in amounts greater than 0.1% of the total esterified fatty acids. The second group contained at least two hundred times more than this minimal level. The volume of lipofuscin granules increased significantly (p less than 0.01) (about threefold for the fat body and twofold in midgut cells) between 3 days and 13 days of age but no statistically significant difference was seen between the two groups of flies at the same age. The results show that if lipofuscin formation depends on the oxidation of polyunsaturated fatty acids in the housefly, then extremely small amounts of the acids are involved which lie below the detection limit of the methods employed. The age-associated small increase of extractable fluorescence seen previously in the linoleic acid group of flies is not associated with an increase in the lipofuscin granules.
通过电子显微镜形态测定法，在两组3日龄和13日龄雄性家蝇中，测定了中肠上皮细胞或腹部脂肪体oenocytes中脂褐素颗粒所占的分数体积。一组由饲养在不含添加多不饱和脂肪酸饲料上的幼虫发育而来，另一组由饲养在添加亚油酸饲料上的幼虫发育而来。使用一种能够检测出其存在量大于总酯化脂肪酸0.1%的方法，在第一组家蝇的脂质中未检测到多不饱和脂肪酸。第二组所含的多不饱和脂肪酸至少比这个最低水平多两百倍。脂褐素颗粒的体积在3日龄至13日龄之间显著增加（p小于0.01）（脂肪体约增加三倍，中肠细胞增加两倍），但在相同年龄的两组家蝇之间未观察到统计学上的显著差异。结果表明，如果脂褐素的形成取决于家蝇中多不饱和脂肪酸的氧化，那么所涉及的酸的量极少，低于所用方法的检测限。先前在亚油酸组家蝇中观察到的与年龄相关的可提取荧光的小幅增加与脂褐素颗粒的增加无关。
