分瓶法测定果蝇吸入麻醉药半数麻醉有效浓度

The ED_(50) of inhaled anesthetics determined by multi-flask method on Drosophila melanogaster

目的 建立测定果蝇吸入麻醉药半数麻醉有效浓度 (ED50 )的方法学。方法 在 11个 32 5ml的三角烧瓶中各放入 30只雄性果蝇 ,分别加入不同容量的异氟醚标准气 ,使 11个烧瓶中异氟醚浓度分布在零效应浓度与百分之百效应浓度之间。以果蝇失去附壁及运动能力为标准计算各瓶中被麻醉果蝇数 ,用正规法计算出ED50 。结果 11次实验在 2 5及 5 0min时的量 -效关系曲线均呈S形 ,用各自的对数浓度与概率单位作图都呈直线相关 ,相关系数分别为 0 .972± 0 .0 14和 0 .971± 0 .0 2 5 ,ED50 值分别为 (0 .5 1± 0 .0 6 8) %和 (0 .4 7± 0 .0 85 ) % ,变异系数分别为 13.3%和 18.0 %。结论 本法稳定性较好 。

Objective To establish a method for determining the anesthetic 50 percent effective dose (ED 50 ) of inhaled anesthetics on fruit flies.?Methods 30 male fruit flies were placed in each of the 11 325-ml flasks for tests. Calibrated isoflurane vapor of different volumes was injected into the flasks, so that its concentrations in the flasks ranged from about 0.2% to 1.2%, as was determined by gas chromatography at 25 minutes. Flies anesthetized by isoflurane lost their capability of attaching to the walls and moving around. Anesthetized flies were counted by the end of 25 or 50 minutes. The experiment was repeated 11 times.?Results The dose-response curve was S-shaped and the logarithmic concentration of isoflurane showed a linear relationship with the probability of flies anesthetized. The correlation coefficients were 0.972±0.014 at 25 minutes and 0.971± 0.025 at 50 minutes. The ED 50 values of isoflurane were (0.51±0.068)% at 25 minutes and (0.47 ±0.085)% at 50 minutes.?Conclusion Our results indicate that the method is stable and practical for determining the ED 50 of inhaled anesthetics on fruit flies.