کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4012620 1261202 2006 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
UV filters in the lens of the thirteen lined ground squirrel (Spermophilus tridecemlineatus)
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی ایمونولوژی و میکروب شناسی (عمومی)
پیش نمایش صفحه اول مقاله
UV filters in the lens of the thirteen lined ground squirrel (Spermophilus tridecemlineatus)
چکیده انگلیسی

Major UV filters have been identified in the lens of the 13 lined ground squirrel (Spermophilus tridecemlineatus). These were found to be N-acetyl-3-hydroxykynurenine and N-acetyl-kynurenine, in addition to a small quantity of 3-hydroxykynurenine. The level of N-acetyl-3-hydroxykynurenine measured in the ground squirrel lens, 8.2 mM, is approximately 11 times the concentration of 3-hyroxykynurenine glucoside reported previously for the human lens. Two additional UV filters of related structure were also present; however, their structures are still under investigation. HPLC elution profiles indicated that the ground squirrel lens cortex and nucleus contained comparable amounts of α-, βH-, βL-, and γ-crystallins. Levels of GSH in the cortex and nucleus were 12.4 and 7.4 mM, respectively. Such high concentrations of GSH may act to inhibit oxidation of the 3-hydroxykynurenine and N-acetyl-3-hydroxykynurenine. N-Acetylated kynurenines are less labile than those with free α-amino groups since N-acetyl-α-amino groups do not undergo spontaneous deamination. This modification thus stabilises the squirrel UV filters. In addition, because deamination is prevented, the decomposition products will not be involved in binding to lens proteins. Because of the similarity of the UV filters present in the ground squirrel to those in man, this species may be a suitable animal model for investigating the effects of UV radiation on cataract, and other ocular diseases, thought to involve exposure to light.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Experimental Eye Research - Volume 82, Issue 4, April 2006, Pages 730–737
نویسندگان
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