Morphological sequelae of intracameral hydrogen peroxide after inhibition of glutathione synthesis.

The morphological sequelae of intracameral injections of hydrogen peroxide on the corneal endothelium were examined under different conditions. In animals pretreated with either intravenous 3-aminotriazole (3AT) alone, to suppress catalase activity, or intravitreal buthionine sulfoximine alone (BSO), to inhibit gamma-glutamyl synthetase activity, the endothelium was normal. The intracameral administration of 10 microliters of 10 mM hydrogen peroxide caused no response after 3AT and some small morphological but not physiological changes after BSO pretreatment. The intracameral injection of 10 microliters of 25 mM hydrogen peroxide caused no additional change in 3AT pretreated rabbits, but caused substantial morphological and physiological changes in BSO pretreated rabbits. The correlation between the present morphological changes and those seen earlier in physiological studies is excellent. The data confirm that the glutathione redox system may be more important than catalase in maintaining the integrity of the corneal endothelium at low aqueous humor concentrations of hydrogen peroxide while catalase assumes greater importance at higher peroxide concentrations.