Cocaine exposure alters H2S tissue concentrations in peripheral mouse organs

BackgroundHydrogen sulfide (H2S) is well-known as a physiological mediator in the mammalian brain and peripheral tissues. Among several factors that change the concentration of H2S, oxidative stress and generation of reactive oxygen species, which accompany neurochemical actions of drugs of abuse, are of recent interest.ObjectiveLimited data on the connection of cocaine and H2S levels prompted us to investigate the effect of this psychostimulant on the H2S concentration in the mouse brain and peripheral organs.MethodsMale BALB/C mice were given several cocaine dosage and treatment regimens, and the free and acid-labile H2S tissue concentrations were determined with a modified spectrophotometric method of Siegel.ResultsWe demonstrated the dose- and treatment-dependent decreases in the H2S level in the heart (83% of control level), and in the liver and kidney (17–34% of control levels) homogenates, but no changes were seen in the mouse brain. The strongest effect occurred after repeated administration of cocaine (20 mg/kg) in all peripheral tissues.ConclusionA reduction in the peripheral tissue H2S level in the heart, liver and kidney homogenates after repeated injections of cocaine may be the result of a strong toxic effect of the drug.