Toxicity and biotransformation of volatile halogenated anesthetics in rat hepatocyte suspensions

This study, examines the toxicity (as measured by reduced intracellular K⁺ and metabolism (defluorination) of halothane and enflurane in rat hepatocytes in suspension (RHS) with regards to O₂ tension, time, and concentration. In 95% O₂ halothane is more toxic than enflurane when RHS are exposed to 5-20 μ1 of these anesthetics. At these levels halothane is not metabolized while enflurane is metabolized. At 21% O₂ a similar pattern was seen with regards to toxicity. However, metabolism of halothane rapidly reached an elevated level while that of enflurane is reduced when compared to 95% O₂. Thus toxicity of halothane and enflurane at these dose levels appears to be unrelated to metabolism and due solely to a solvent effect.