Yappert M C, Lal S, Borchman D
Department of Chemistry, University of Louisville School of Medicine, Kentucky.
Invest Ophthalmol Vis Sci. 1992 Dec;33(13):3555-60.
This is comprehensive study of the age dependence and regional distribution of the blue and the green fluorophores, per unit protein, (specific fluorescence) in the human lens. Spectroscopic measurements were obtained using fiber optic sensors that considerably improved upon techniques used in the past because inner-filter and scattering effects were minimized. An increase in the specific green and blue fluorescence was observed with increasing age in the soluble and insoluble nuclear fractions. In the cortical fractions, an increase with age was observed in lenses of donors under 30 yr old. No significant variations in the specific fluorescence were measured beyond the third/fourth decade of life in the cortical fractions. The specific fluorescence was about twice as high in samples from the cortex compared to those from the nucleus. The insoluble protein fractions also exhibited twice as much specific fluorescence compared to the soluble ones. At older ages, the fluorescence level of insoluble proteins was always greater than that in soluble ones, but the specific fluorescence of insoluble fractions from young lenses was less than that of soluble older lenses. The greater fluorescence per unit protein may be just a manifestation or marker of the insolubilization process. Furthermore, because a threshold level of specific fluorescence was observed in the cortical fraction of clear lenses, it is likely that fluorophor formation is not a marker of aging in this region, as it is in the nuclear region in which the specific fluorescence increases with increasing age, perhaps reaching a threshold level beyond which cataractogenesis may occur.
这是一项关于人晶状体中蓝色和绿色荧光团（每单位蛋白质的特定荧光）的年龄依赖性和区域分布的综合研究。使用光纤传感器进行光谱测量，该传感器极大地改进了过去使用的技术，因为内滤光和散射效应被最小化。在可溶性和不可溶性核部分中，随着年龄的增长，特定绿色和蓝色荧光增加。在皮质部分中，观察到30岁以下供体的晶状体中荧光随年龄增加。在生命的第三个/第四个十年之后，皮质部分的特定荧光没有测量到显著变化。皮质样品的特定荧光大约是核样品的两倍。与可溶性蛋白质部分相比，不溶性蛋白质部分的特定荧光也高出两倍。在老年时，不溶性蛋白质的荧光水平总是高于可溶性蛋白质，但年轻晶状体不溶性部分的特定荧光低于可溶性老年晶状体。每单位蛋白质更高的荧光可能只是不溶性化过程的一种表现或标志。此外，由于在透明晶状体的皮质部分观察到特定荧光的阈值水平，荧光团形成在该区域可能不是衰老的标志，而在核区域中特定荧光随年龄增加，可能达到一个阈值水平，超过该水平可能发生白内障形成。
