Glutathione and glutathione S-transferases in rat liver after inhalation of halothane and enflurane

Male Sprague-Dawley rats were exposed in inhalation chambers to halothane and enflurane in concentrations from 50 ppm-1000 ppm (0.0025-0.05 minimum alveolar concentration; MAC) 6 h a day for 3-9 days. Repeated subanaesthetic concentrations were used to avoid effects of general anaesthesia and to increase the metabolized fraction of the inhaled anaesthetics. Exposure to 0.05 MAC of halothane (500 ppm) and enflurane (1000 ppm) for 9 days reduced the activity of glutathione S-transferases. A decrease in liver concentration of reduced glutathione (GSH) was observed after inhalation of enflurane, probably caused by metabolic release of inorganic fluoride. The results indicate a decreased detoxifying capacity of rat liver under the given conditions. Inhalation of occupational related concentrations of the anaesthetics (50 ppm) did neither affect the activity of the transferases nor the concentration of GSH in rat liver.