The effect of buthionine sulfoximine on the glutathione level in goldfish tissues.

This study describes the effect of DL-buthionine-[S,R]-sulfoximine (BSO) on the glutathione equivalents (GSH-eq = GSH + 2 GSSG) of goldfish. BSO causes depletion of cellular GSH by inhibiting gamma-glutamylcysteine synthetase, a key enzyme of the GSH biosynthesis pathway. BSO at 1,000 and 1,500 mg/kg was effective in promoting 50 and 80% depletion of GSH-eq from brain and liver, respectively, within 3 days. Lower doses of BSO failed to effectively promote hepatic GSH-eq depletion. Moreover, no evident toxic side-effects were observed (including hepatic lipid peroxidation and free radical-mediated oxidation of proteins) in goldfish in response to BSO intraperitoneal injections. We conclude that BSO can be used to deplete GSH-eq in goldfish liver and brain, but attention should be paid to species-specific variations in BSO effects.