Ringvold A, Anderssen E, Kjønniksen I
Eye Department, National Hospital, Oslo, Norway.
Invest Ophthalmol Vis Sci. 2000 Jul;41(8):2067-9.
To analyze the components responsible for the UV absorbance in diurnal bird aqueous humor.
The absorbance studies were carried out using a Hitachi spectrophotometer (U 2000). Uric acid was determined by high-performance liquid chromatography (LC-10 system; Shimadzu, Kyoto, Japan). Chicken and turkey eyes were examined.
The UV absorbance in chicken aqueous was largely accounted for by the presence of protein, tryptophan, tyrosine, ascorbic acid, and uric acid. Ascorbic acid was low (23 micromol/l). Uric acid was, on the other hand, remarkably high (151 micromol/l) compared with that in mammals (cattle, 16 micromol/l). Principally the same results were obtained in chicken and turkey.
Uric acid is a significant UV-absorbing substance in the aqueous humor of diurnal birds with its peak absorbance at 292 nm. The hypothesis that the aqueous humor acts as a UV filter seems to be valid also for the avian eye. However, in these eyes uric acid fulfills the role that ascorbic acid does in mammals.
分析白昼活动鸟类房水中负责紫外线吸收的成分。
使用日立分光光度计(U 2000)进行吸光度研究。尿酸通过高效液相色谱法(LC - 10系统;日本岛津公司,京都)测定。对鸡和火鸡的眼睛进行了检查。
鸡房水中的紫外线吸收主要由蛋白质、色氨酸、酪氨酸、抗坏血酸和尿酸引起。抗坏血酸含量较低(23微摩尔/升)。另一方面,与哺乳动物(牛,16微摩尔/升)相比,尿酸含量非常高(151微摩尔/升)。在鸡和火鸡中获得了基本相同的结果。
尿酸是白昼活动鸟类房水中一种重要的紫外线吸收物质,其最大吸收波长在292纳米。房水充当紫外线滤光器的假设似乎对鸟类眼睛也成立。然而,在这些眼睛中,尿酸起到了哺乳动物眼中抗坏血酸所起的作用。