AGE-RELATED INCREASE IN LIVER RETINYL PALMITATE--RELATIONSHIP TO LIPOFUSCIN

脂褐素是一个通用术语，指的是呈现绿色的物质， 黄色荧光并随着年龄的增长在细胞中积累。 由于其 与年龄相关的增加和似乎普遍存在，脂褐素是 被认为是衰老的标志 然而，相对较少的直接 脂褐质的化学证据是存在的。 的目标 我们的研究是从Fisher-344大鼠的肝脏中分离和鉴定， 这些荧光物质随着年龄的增长而增加。 我们报告，洗涤剂溶解的肝脏的荧光强度 从Fisher-344大鼠中获得的蛋白质作为年龄的函数而增加。 荧光团 负责这种增加是用甲醇提取，可以 当甲醇提取物从其他细胞组分中分离时， 在反相柱上进行色谱分离。 该物质的FAB-MS 显示525的准分子离子，表明棕榈酸视黄酯是 可能的结构。 该化合物经进一步鉴定为视黄基 棕榈酸酯，通过与真实棕榈酸视黄酯共洗脱和检查 其质子核磁共振谱与文献报道完全雅阁 以前。 棕榈酸视黄酯在肝脏中的水平被发现， 在Fisher-344大鼠的整个生命周期中增加（2至24 月）以接近线性的方式，从0.26至1.77 mg/g的值 肝脏 正如脂褐素的报道，棕榈酸视黄酯 聚集在细胞内颗粒中， 荧光。 由于这些相似性， 棕榈酸视黄酯和脂褐素值得进一步研究。 棕榈酸视黄酯是一种亲脂性化合物， 双键 一种有趣的可能性是棕榈酸视黄酯 保护细胞免受自由基损伤，这一过程一直是 与细胞衰老有关 棕榈酸视黄酯能够 保护不饱和脂肪酸，从而保护细胞膜， 将研究过氧化损伤。

Lipofuscin is a general term assigned to material that exhibits greenish- yellow fluorescence and accumulates in cells as they age. Because of its age-related increase and seemingly universal occurance, lipofuscin is considered a hallmark of aging. However, relatively little direct chemical evidence as to the identity of lipofuscin exists. The goal of our study was to isolate and identify, from livers of Fisher-344 rats, those fluorescent materials which increase with age. We report that the fluorescent intensity of detergent-solubilized liver from Fisher-344 rats increased as a function of age. The fluorophore responsible for this increase was extracted with methanol and could be resolved from other cellular components when the methanol extracts were chromatographed over a reverse phase column. FAB-MS of this substance showed a quasi-molecular ion of 525, indicating retinyl palmitate as a possible structure. The compound was further identified as retinyl palmitate by coelution with authentic retinyl palmitate and by inspection of its proton NMR spectrum which was in full accord with that reported previously. The level of retinyl palmitate in the liver was found to increase throughout the entire life of the Fisher-344 rat (2 to 24 months) in a nearly linear fashion, from a value of 0.26 to 1.77 mg/g of liver. As has been reported for lipofuscin, retinyl palmitate accumulates in intracellular granules and exhibits greenish-yellow fluorescence. Due to these similarities, the relationship between retinyl palmitate and lipofuscin warrants further investigation. Retinyl palmitate is a lipophilic compound containing five conjugated double bonds. One intriguing possibility is that retinyl palmitate protects the cell from free radical damage, a process which has been implicated in cellular aging. The ability of retinyl palmitate to protect unsaturated fatty acids, and thus cell membranes, from peroxidative damage will be investigated.