Effect of in vivo administration of anesthetics on GABAA receptor function

In research involving tissue derived from animals, the use of anesthesia before sacrifice is recommended by the American Veterinary Medical Association and is strongly encouraged by university committees on the use of animals in research. In this study, the effects of anesthesia on the modulation of the GABAA receptor complex by ethanol, a benzodiazepine, and a barbiturate were determined. In vivo administration of the anesthetic methoxyflurane and CO2 before sacrifice resulted in a decrease in Cl- flux in mouse brain microsacs. These treatments also resulted in the loss of the ability of the GABAA receptor modulatory agents flunitrazepam and ethanol to enhance the Cl- flux in this assay system.