ABSTRACT
The tripeptide glutathione plays an important role in a large number of biological phenomena. Its function is particularly important in hepatic detoxification processes due to reactions catalyzed by glutathione peroxidases and glutathione S-transferases. The latter enzyme catalyzes the interaction between glutathione and many electrophilic metabolites of xenobiotics, increasing the hydrophilicity of ligands and facilitating the hepatic excretory function. Glutathione S-transferases are also able to bind nonsubstrate hydrophilic compounds and a transport function related to this binding property has been suggested. The effects of glutathione S-transferases-mediated biotransformation on the excretory process of different xenobiotics can be studied in several ways including depletion of cellular glutathione or modifications in the enzyme activity. Glutathione is not only involved in the biotransformation process but also influences the canalicular transport of xenobiotics. A competition between canalicular glutathione and glutathione conjugates transport via the same carrier system has been reported. This review focuses on the different aspects of the relationship between glutathione and the hepatobiliary transport of xenobiotics.
