Oxidant/antioxidant state in tissue of prymary and recurrent pterygium

Abstract

BackgroundPterygium is a disorder of the ocular surface induced by chronic exposure to UV-light. Abundant data is available from patients with primary pterygium, but scarce from those with recurrent pterygium. The present study aimed to explore the oxidant/antioxidant status in tissue of primary and recurrent pterigium in men and women.MethodsPathological tissue samples were taken during surgery on patients with primary and recurrent pterygium. Healthy conjunctive tissue samples were taken during cataract surgery. After homogenization of 77 tissue samples, evaluation was made of thiobarbituric reactive substances (TBARS), nitric oxide (NO), total antioxidant status (TAS) and the activity of the three main antioxidant enzymes: glutathione peroxidase, superoxide dismutase and catalase. Gender differences were evaluated.ResultsCompared to the control group, in the primary pterygium group there was an increase in NO and TAS, and a tendency to a decrease of all antioxidant enzymes, indicating an increase in non-enzymatic antioxidant activity. Compared to the control group, in the recurrent pterygium group there was a significant decrease in the level of TAS and antioxidant enzymes. A high positive correlation was found between most of measured parameters within the control group and the recurrent pterygium group, but not within the primary pterygium group. Compared to men, a significant difference was observed in the elevated NO level and low TAS level of women in the prymary pterygium group.ConclusionsThe diminished antioxidant defense in the recurrent pterygium group, possibly determined mainly by decreased non-enzymatic activity, supports the idea that oxidative stress plays an important role in the recurrence of this disorder.

Pterygium: Glutathione, Nitric Oxide Production and N-Acetylcysteine Treatment

“…The latter could recover this loss of GSH from blood flow proceeding from the liver. In this study, we have observed a decrease in eNOS, NO, and 3NT in pterygium tissue, while in the previous research, no significant change in lipoperoxidation (TBARS) was found in pathological tissues [6]. Then it is likely that nitrosative stress slope decreases the inactivation rate of GSH and CAT in recurrent pterygium resulting in their increase.…”

“…Their effect then results from the balance between negative for oxidative stress and positive for their physiological effects. Data on NO levels in pterygium tissue are contradictory, from high, which was probably determined by high levels in women [6], to decreased [7]. There are data on the close relationship between NO and metabolism and/or transport of GSH, which synthesizes in all tissues but large quantities, mainly in the liver.…”

Protective Role Of Glutathione And Role Of Nitric Oxide Production In The Pathogenesis Of Pterygium 

“…The synthesis and/or redistribution of glutathione (GSH) is one such possible mechanism. Reports on NO in pterygium tissue are contradictory, as both low [6] and high levels [7] have been found, the latter reflecting probably the quantity of women in the study (by higher levels of NO in women, compared to men). The overall effect of NO and related molecules revolves around the balance between the positive physiological ramifications of their signaling and the negative consequences of oxidative stress.…”

Cultivation and characterization of pterygium as an ex vivo study model for disease and therapy

“…Likely, the expression of these cytokines is closely related to the factors associated with the niche where pterygia sit in vivo, where they are closely related to the neighbouring limbus and its abundant vasculature underlying it. A balanced antioxidant defence in patients following primary pterygium surgery is also important [30]. 8-OHdG is a ubiquitous marker of oxidative stress with a high mutagenic potential.…”