Minimal biotransformation and toxicity of desflurane in guinea pig liver slices

Biotransformation and hepatotoxicity of desflurane were evaluated in the guinea pig liver slice culture system. Liver slices (250-300 μm) were prepared from 600-650-g male Hartley guinea pigs. The slices were incubated in sealed vials in a Krebs-Henseleit buffer at 37°C under 95% O₂. Desflurane was vaporized to produce media concentrations of 0.7-2.3 mM. After incubation (3-24 h) viability of the slices was determined (K⁺ content; protein synthesis/secretion) along with the biotransformation of desflurane (F^-). Isoflurane (2.3 mM) was included in the studies for comparative purposes. Although desflurane caused a mild concentration-related reduction in slice K⁺ content (1.1-2.2 mM; 20%-40% of control), the effects were less than those produced by 2.3 mM isoflurane (50% of control). High concentrations of desflurane decreased protein synthesis at the first 9 h of incubation, and isoflurane decreased protein synthesis throughout the incubation period. Neither anesthetic affected protein secretion. The biotransformation of desflurane was minimal with threefold less F^- produced from desflurane than isoflurane.