麻醉药对[Ca2＋]i的多途径改变及相关生物学效应

Ca2＋是细胞内的第二信使．它参与细胞内很多生理活动过程．包括神经递质释放．肌肉收缩,腺体分泌．学习记忆及细胞凋亡等。麻醉药可以通过多种方式直接或间接改变[Ca2＋]i从而对生物体产生错综复杂的影响．这些影响有些与麻醉作用有关有些与麻醉作用无关。     

Anesthetic action of volatile anesthetics by using Paramecium as a model

Although empirically well understood in their clinical administration, volatile anesthetics are not yet well comprehended in their mechanism studies. A major conundrum emerging from these studies is that there is no validated model to assess the presumed candidate sites of the anesthetics. We undertook this study to test the hypothesis that the single-celled Paramecium could be anesthetized and served as a model organism in the study of anesthetics. We assessed the motion of Paramecium cells with Expert Vision system and the chemoresponse of Paramecium cells with T-maze assays in the presence of four different volatile anesthetics, including isoflurane, sevoflurane, enflurane and ether. Each of those volatiles was dissolved in buffers to give drug concentrations equal to 0.8, 1.0, and 1.2 EC50, respectively, in clinical practice. We could see that after application of volatile anesthetics, the swimming of the Paramecium cells was accelerated and then suppressed, or even stopped eventually, and the index of the chemoresponse of the Paramecium cells (denoted as Iche) was decreased. All of the above impacts were found in a concentration-dependent fashion. The biphasic effects of the clinical concentrations of volatile anesthetics on Paramecium simulated the situation of high species in anesthesia, and the inhibition of the chemoresponse also indicated anesthetized. In conclusion, the findings in our studies suggested that the single-celled Paramecium could be anesthetized with clinical concentrations of volatile anesthetics and therefore be utilized as a model organism to study the mechanisms of volatile anesthetics.     

右美托咪定用于七氟醚诱导气管插管时血流动力学及BIS的变化

目的：观察右美托咪定对七氟醚诱导气管插管时血流动力学及镇静深度的影响。方法：择期全麻下行耳鼻喉手术患者36例,ASA分级Ⅰ~Ⅱ级,随机均分为对照组（ A组）、高剂量芬太尼组（ B组）、右美托咪定组（ C组）,A、B组诱导时分别给予芬太尼2μg/kg和4μg/kg,C组麻醉诱导前15 min内静脉泵注右美托咪定1.0μg/kg,诱导时给予芬太尼2μg/kg;3组均给予七氟醚“潮气量法”诱导,记录3组患者给药前（ T0）、开始吸入七氟醚即刻（ T1）、气管插管前即刻（ T2）、气管插管后即刻（ T3）的收缩压（ SBP）、舒张压（ DBP）、心率（ HR）、脑电双频指数（ BIS）并分析。结果：3组患者T0时点基础BIS、SBP、DBP及HR比较;差异无统计学意义（ P>0.05）;T1与T0时点比较,C组SBP、HR及BIS值显著低于A、B两组,T2时点C组患者的SBP 显著高于A、B两组,差异有统计学意义（ P<0.05）;T3时点C组患者的SBP、DBP及HR显著低于A组,BIS低于A、B两组,差异有统计学意义（ P<0.05）。结论：七氟醚诱导插管时右美托咪定在降低BIS的同时可维持稳定的血流动力学。