Role of glutathione in the regulation of anterior chamber hydrogen peroxide.

Catalase inhibition leads to an increase in the t 1/2 for hydrogen peroxide loss from the anterior chamber and increased tissue damage. BCNU (1,3-bis-(2-chloroethyl)-l-nitrosourea) and BSO (buthionine sulfoxamine) were used to suppress glutathione reductase and glutathione synthesis, respectively. Intravitreal BSO (1 to 4 mg) reduced total glutathione levels of iris by 80%, and aqueous glutathione levels by 70%. BSO caused the t 1/2 for hydrogen peroxide disappearance from the anterior chamber to increase after 10 microliters of 10 mM peroxide was injected intracamerally but not after 25 or 50 mM peroxide injections. Catalase inhibition, however, had more influence at 50 mM than with 10 or 25 mM injections. The glutathione redox system is operative at low aqueous hydrogen peroxide concentrations and catalase is of greater importance at higher peroxide concentrations.