Sevoflurane Preconditioning Decreases The Death Rate Of Three Strains Of Drosophila Menlanogaster After Anoxia

Background Sevoflurane preconditioning produced organ protections inspecies. However, whether sevoflurane preconditioning would protect thewhole organism but not individual organ is uncertain. The sevofluranesensitive strain (S), wild strain (H) and sevoflurane resistive strain (R) ofDrosophila menlanogaster (fruit fly) have been bred in our laboratory. Thepurpose of this study was to define whether sevoflurane preconditioningwould decrease the death rate of three strains of fruit fly after anoxia.Methods According to different sevoflurane concentrations preconditioned,we conducted six experimental series in three strains of fruit flies, including0.5ED₅₀, 1.0ED₅₀, 1.5ED₅₀, 2.0ED₅₀, 2.5ED₅₀, and 3.0ED₅₀ seriesexperiments. In each experimental series, 32 tubes of fruit flies in each strain(40 fruit flies in each tube, 2～3 d) were included, 24 tubes of which wereexposed to: (1) sevoflurane for 5 min followed by 30 min of reoxygen (sevoflurane preconditioning group, n=8), (2)anoxia for 5 min followed by 30min of reoxygen (anoxia preconditioning group, n=8), (3)normoxia for 35min(anoxia group,n=8). Then the fruit flies of above three groups were exposedto anoxia for 4h. The remaining eight tubes of fruit flies was exposed tonormoxia throughout the study as control group. The dead fruit flies werecounted after 72 h and the death rate as well as the calibrated death rate wascalculated. All data were reported as mean±SD. Two-way ANOVA was usedto compare the differences of the calibrated death rate.Results Proper concentrations of sevoflurane with 1.5ED₅₀, 2.0ED₅₀, 2.5ED₅₀in S and H strains and 1.0ED₅₀, 1.5ED₅₀, 2.0ED₅₀, and 2.5ED₅₀ in R straindecreased the death rate when compared with the same strain of anoxia group.Anoxia preconditioning decreased the death rate in all strains of fruit flies(P＜0.05,). However, there were no differences in the death rate betweenthe sevoflurane and anoxia preconditioning groups in the same strain. Lowconcentrations of sevoflurane with 0.5ED₅₀, 1.0ED₅₀ in S and H strains and0.5ED₅₀ in R strains and high concentrations of sevoflurane with 3.0 ED₅₀in H and R strains did not affect the death rate, but high concentrations ofsevoflurane (3.0 ED₅₀)in S strains increased the death rate of fruit flies. Insevoflurane preconditioning group with certain concentration, the death ratewas not significantly different between three strains of fruit flies. Conclusion Our investigation showed that sevoflurane preconditioning withproper concentrations produced similar protective effects to anoxiapreconditioning by reducing the death rate in three strains of fruit flies.