Lens superoxide dismutase and catalase activities in diabetic cataract.
OBJECTIVE
Biochemical evidence suggests that the oxidative damage of the lens proteins is involved in the genesis of senile cataract and the development of diabetes-related pathologic changes such as the formation of cataracts. In particular, lens proteins are subject to extensive oxidative modification. Oxidative damage either decreases the antioxidant capacity or decreased antioxidant capacity results in oxidative damage. The purpose of this study was to analyze the activities of the antioxidant enzymes such as Cu,Zn Superoxide Dismutase (Cu,Zn-SOD) and catalase in the cataractous lenses of the type 2 diabetic group and cataractous lenses of the senile group.


METHODS
Eighteen diabetic cataractous lenses and twenty six senile cataractous lenses were studied. Cu,Zn-SOD activity was measured in lenses by enzymatic method and catalase activity was measured by colorimetric method.


RESULTS
Cu,Zn-SOD levels were significantly lower in the diabetic cataractous lenses than senile cataractous lenses (respectively 8.052 +/- 0.818, 18.216 +/- 4.217 microg/g prot. p < 0.05). Similarly, catalase levels were significantly lower in the diabetic cataractous lenses than senile cataractous lenses (respectively 0.326 +/- 0.134, 0.665 +/- 0.322 kU/g prot. p < 0.001).


CONCLUSIONS
The results of the present study indicate that the antioxidant capacity in the diabetic cataractous lenses were decreased and this result suggests a role of antioxidant enzymes in the genesis of diabetic cataracts.
Ozmen
Bilgin
B
Department of Internal Medicine (Endocrinology), Celal Bayar University School of Medicine, Manisa, Turkey.
Ozmen
Dilek
D
Erkin
Esin
E
Güner
Inci
I
Habif
Sara
S
Bayindir
Oya
O
D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D002374:Catalase / Q000378:metabolism*; D002386:Cataract / Q000201:enzymology* / Q000209:etiology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000201:enzymology*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D006801:Humans; D007908:Lens, Crystalline / Q000201:enzymology*; D008297:Male; D008875:Middle Aged; D008982:Molybdenum / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000378:metabolism
D000975:Antioxidants; D008982:Molybdenum; D002374:Catalase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D005978:Glutathione; C022175:ammonium molybdate