Modulation of Ocular Eicosanoid Biosynthesis by Oxidants and Anti-oxidants

Abstract

The association betwen oxidative damage and inflammation is well documented (Bragt et al. 1980), and arachidonate metabolites are important modulators of the inflammatory response in animal and human tissues including the eye (Eakins et al. 1972; Masuda et al. 1973). Ocular tissues generate eicosanoids by both cyclo-oxygenase and lipoxygenase pathways (Bhattacherjee et al. 1979; Kass and Holmberg 1979; Kulkarni et al. 1984). Since it has been suggested that arachidonate metabolism is regulated by the endogenous peroxide concentration metabolism is regulated by the endogenous peroxide concentration (Hemler and Lands 1980) we proposed to investigate the effect of changing the oxidative environment in vitro upon arachidonate metabolism in the iris-ciliary body and cornea; for comparison lung, spleen and platelet were also examined. The oxidant studied was hydrogen peroxide and the anti-oxidants employed were ascorbate, glutathione and ebselen, a seleno-organic compound with established glutathione peroxidase-like activity (Wendel et al. 1984). Much of the data to be given here has been previously presented (Hurst et al. 1987b) and has been submitted for publication in detail elsewhere.