Manabe S, Wada O, Urban R C
Department of Hygiene & Preventive Medicine, Faculty of Medicine, University of Tokyo, Japan.
Exp Eye Res. 1993 Sep;57(3):319-24. doi: 10.1006/exer.1993.1130.
A fluorescent carcinogen, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) has been identified in both human normal lenses and cataractous lenses. The total amounts of PhIP in normal lenses were 50.7 +/- 36.0 pg (n = 7) while those of PhIP in senile and diabetic cataractous lenses were 143 +/- 29.2 pg (n = 10) and 148 +/- 55.0 pg (n = 10), respectively. Although it was not possible to strictly compare the contents of PhIP among normal, senile and diabetic lenses, due to the limited numbers of normal lenses available, the mean total amounts of PhIP in normal lenses were the lowest among normal, senile and cataractous lenses when allowing for differences in age. Furthermore, there was a significant correlation between total amounts of PhIP in human lenses, and age of the lens, suggesting that the content of PhIP in human lens is increased with age. In all types of lenses, the concentrations of PhIP in the insoluble-protein fraction (pg mg-1 protein) were significantly higher than those in the water-soluble protein fraction. In addition, PhIP was formed when bovine lens was incubated at 37 degrees C under the presence of creatinine and glucose for various time periods, and the yield of PhIP during incubation was found to be time-dependent. The results from our study suggest that PhIP may be one of the age-related fluorogens in the human lens.
一种荧光致癌物，2-氨基-1-甲基-6-苯基咪唑并[4,5-b]吡啶（PhIP）已在人类正常晶状体和白内障晶状体中被鉴定出来。正常晶状体中PhIP的总量为50.7±36.0皮克（n = 7），而老年性和糖尿病性白内障晶状体中PhIP的总量分别为143±29.2皮克（n = 10）和148±55.0皮克（n = 10）。尽管由于可用的正常晶状体数量有限，无法严格比较正常、老年性和糖尿病性晶状体中PhIP的含量，但考虑到年龄差异，正常晶状体中PhIP的平均总量在正常、老年性和白内障晶状体中是最低的。此外，人类晶状体中PhIP的总量与晶状体年龄之间存在显著相关性，这表明人类晶状体中PhIP的含量随年龄增长而增加。在所有类型的晶状体中，不溶性蛋白质部分（皮克/毫克蛋白质）中PhIP的浓度显著高于水溶性蛋白质部分。此外，当牛晶状体在肌酐和葡萄糖存在下于37℃孵育不同时间段时会形成PhIP，并且发现孵育过程中PhIP的产量与时间相关。我们的研究结果表明，PhIP可能是人类晶状体中与年龄相关的荧光原之一。
