Effect of repeated ether anesthesias on levels and stability of monooxygenase system activities of mouse liver.

A short diethyl ether anesthesia before the three injections to induce xenobiotic metabolizing monooxygenase in mice for the preparation of liver S-9 fraction used in mutagenesis test in vitro does not negatively alter the biochemical properties of the activating system and gives unchanged genetic results. Instead, the use of more prolonged ether anesthesia also at the day of the sacrifice, results in less active and less stable enzymes in the S-9 fraction, which can lead to altered genetic results.