Inhibition of glutathione S-transferases from rat liver by basic triphenylmethane dyes.
(1) Basic triphenylmethane dyes related to pararosanilin inhibit class alpha glutathione S-transferases (GSTs) from rat liver. The inhibitory potency of each dye correlates with its octanol-water partition coefficient. Values of Ki determined at pH 6.5 ranged from about 1 x 10(-7) M for Ethyl violet to 7 x 10(-5) M for Methyl green. GST 3-3, a class mu isoenzyme, was an order of magnitude less sensitive to inhibition by Ethyl violet. (2) All of the dyes tested were bleached to varying degrees by glutathione. The bleaching appears to result from the formation of an adduct between the dye and glutathione. At pH 6.5, adduct formation is significant only for Malachite green and Methyl green. There is kinetic evidence that for these dyes the adduct contributes significantly to the overall inhibition. It is probable that at physiological pH, all of the dyes would exist to a significant extent in the adduct form. (3) The dyes are excreted extensively in the bile, at least partly as the glutathione adduct. The free dye is regenerated on standing, it is assumed as a result of removal of glutathione by oxidation.[1]References
- Inhibition of glutathione S-transferases from rat liver by basic triphenylmethane dyes. Debnam, P., Glanville, S., Clark, A.G. Biochem. Pharmacol. (1993) [Pubmed]
Annotations and hyperlinks in this abstract are from individual authors of WikiGenes or automatically generated by the WikiGenes Data Mining Engine. The abstract is from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.About WikiGenesOpen Access LicencePrivacy PolicyTerms of Useapsburg
