Mechanism of action, metabolism, and toxicity of buthionine sulfoximine and its higher homologs, potent inhibitors of glutathione synthesis.

The abbreviations used are: GSH, glutathione (reduced); GSSG, glutathione disulfide.Total glutathione refers to GSH equivalents determined as described under "Experimental Procedures."It is essentially GSH + 2 X GSSG; intracellular GSSG << GSH.a-Ethylmethionine sulfoximine is a specific inhibitor of glutamine synthetase (7).