The Activities of Paraoxonase, Xanthine Oxidase, Adenosine Deaminase and the Level of Nitrite in Pseudoexfoliation Syndrome

Abstract

Aim: Our purpose was to investigate the possible roles of nitrite levels and the activity of paraoxonase (PON), xanthine oxidase (XO) and adenosine deaminase (ADA) in the pathogenesis of pseudoexfoliation (PEX) syndrome. Methods: Serum samples were taken from 43 patients with PEX and 41 control subjects. The serum PON, XO and ADA activities and nitrite levels were assayed by spectrophotometric methods. Results: The PON, ADA and XO activities and nitrite levels (means ± standard deviation) were 81.72 ± 42.56 U/ml, 19.75 ± 5.72 U/l, 0.16 ± 0.09 U/l and 94.23 ± 27.72 μmol/l in the PEX group, respectively. In the control group, the PON, ADA and XO activities and the nitrite levels were 111.02 ± 43.51 U/ml, 15.21 ± 3.93 U/l, 0.13 ± 0.06 U/l and 61.96 ± 19.05 μmol/l, respectively. The serum PON activity was significantly lower in the PEX group when compared with the control group. The serum XO and ADA activities and nitrite levels were significantly higher in the patients with PEX when compared with the control subjects. Conclusion: Decreased PON (an antioxidant enzyme) activity as well as increased ADA and XO activities and nitrite levels indicate that oxidative stress is increased and purine metabolism is altered in PEX syndrome.