Biotransformations occurring with glutathione

Biotransformations Occurring with Glutathione Conjugates (Table I)... 

Different enzymatic reactions that occur during the metabolism of chemicals have been well categorized. The biotransformation and conjugation reactions may lead to either the detoxication of the toxicant and the excretion of its metabolites, or to the activation of the toxicant into more reactive intermediates. These may, in turn, react with glutathione, or tissue proteins, or nucleic acids (e.g., RNA, DNA) and undergo different metabolic reactions. 

Biotransformation involves oxidation via the cytochrome P450 system and subsequent detoxification by conjugation with glutathione and cellular macromolecules. The oxidative metabolic pathway is saturable, occurring at an oral dose of 10-50 mg kg in the rat, and at inhalation exposures exceeding 200 ppm. Elimination of vinylidene chloride and its metabolites occurs primarily through the urine and in the expired air at a relatively rapid excretion rate. 

With compounds of sufficient reactivity, these reactions can also occur nonenzymatically. Once formed, glutathione conjugates (GS-R) are seldom excreted as such, but usually undergo further biotransformation. Cleavage of the glutamyl moiety by glutamyl transpeptidase and of the cysteinyl... 

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