[The association between copper ions and peroxidative reaction in diabetic cataract].
The concentration of copper ions in cataractous lenses was higher than that in clear lenses. The concentration was significantly higher in the diabetic (DM) group than in the non-diabetic (control) group. Compared to Cu4, the concentration of Cu24 was significantly greater in the DM group. The concentration of protein-unconjugated copper ions was higher than that of protein-conjugated copper ions. I assume that in cataractous lenses of the DM group, decrease of the reactivity of copper-containing enzyme, Cu, Zn-SOD (Cu, Zn-superoxide dismutase), and increase of hydrogen peroxide lead to generation of hydroxyl radicals from a Fenton-like reaction. In diabetes, the increase of lenticular glucose induced glycation and the release of copper ions from copper-containing enzyme, followed by the increase of lenticular copper ions. As a result, superoxide scavenging activity was reduced and peroxide lipid was increased. I assume this to be due to hyperactivity of the cascade of peroxidation.
Lin
J
J
Department of Ophthalmology, Koshigaya Hospital, Dokkyo University School of Medicine, Saitama-ken, Japan.
D000368:Aged; D002386:Cataract / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism*; D008875:Middle Aged; D013482:Superoxide Dismutase / Q000378:metabolism*
D003300:Copper; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase