Etomidate protects retinal ganglion cells from hydrogen peroxide-induced injury via Nrf2/HO-1 pathway

AIM:To determine whether etomidate(ET)has a protective effect on retinal ganglion cells(RGCs)injured with hydrogen peroxide(H_(2)O_(2))and to explore the potential mechanism underlying the antioxidative stress effect of ET.METHODS:Cultured RGCs were identified by double immunofluorescent labeling of microtubule-associated protein 2 and Thy1.1.An injury model of H_(2)O_(2)-induced RGCs oxidative stress was established in vitro.Cells were pretreated with different concentrations of ET(1,5,and 10μmol/L)for 4h,followed by further exposure to H_(2)O_(2)at 1000μmol/L.Cell counting kit 8 and Annexin V/propidium iodide assays were applied to detect the viabilities and apoptosis rates of the RGCs at 12,24,and 48h after H_(2)O_(2)stimulation.The levels of nitric oxide,malondialdehyde,and glutathione in culture media were measured at these time points.Quantitative reverse transcription polymerase chain reaction(qRT-PCR)and Western blot were performed to observe the effects of ET on the messenger RNA and protein expression of inducible nitric oxide synthase(iNOS),nuclear factor erythroid 2-related factor 2(Nrf2),heme oxygenase 1(HO-1),glutathione peroxidase 1 and the level of conjugated acrolein in RGCs at 12,24,and 48h after H_(2)O_(2)stimulation and in the retina at 12h after optic nerve transection(ONT).RESULTS:The applications of 5 and 10μmol/L of ET significantly increased the viability of RGCs.Results from qRT-PCR indicated a decrease in the expression of iNOS and an increase in the expressions of Nrf2 and HO-1 in ETpretreated RGCs at 12,24 and 48h after H_(2)O_(2)stimulation,as well as in ET-treated retinas at 12h after ONT.Western blot analysis revealed a decrease in the expression of iNOS and levels of conjugated acrolein,along with an increase in the expressions of Nrf2 and HO-1 in ET-pretreated RGCs in vitro and ET-treated retinas in vivo.CONCLUSION:ET is a neuroprotective agent in primary cultured RGCs injured by H_(2)O_(2).The effect of ET is dosedependent with the greatest effect being at 10μmol/L.ET plays an antioxidant role by inhibiting iNOS,up-regulating Nrf2/HO-1,decreasing the production of acrolein,and increasing the scavenge of acrolein.

Retrospective Review of Propofol versus Etomidate during Rapid Sequence Intubation in the Emergency Department at a Tertiary Academic Center

Background: Etomidate is the standard induction agent used during rapid sequence intubation (RSI) in the emergency department (ED). Etomidate shortages require providers to utilize alternative agents. The purpose of this study is to compare the safety and procedural outcomes of propofol and etomidate for RSI in the ED. Methods: This was a retrospective chart review of adult patients in the ED who received propofol or etomidate for induction during RSI. The main endpoint was hypotension, defined as a systolic blood pressure < 90 mmHg or diastolic blood pressure < 60 mmHg, within the first hour of intubation. Time to intubation, intensive care unit length of stay, hospital length of stay, and in-hospital mortality were also evaluated. Results: Two hundred and seventy five patient charts were reviewed. Of the 98 patients included, 43 patients received propofol and 55 patients received etomidate. Propofol was associated with an increased incidence of hypotension within the first hour of intubation (65.1% vs. 25.5%, p < 0.001). No difference was found in the time to intubation: ≤5 minutes (51.2% vs. 34.6%, p = 0.83). The mortality rate was 11.6% in the propofol group and 27.3% in the etomidate group (p = 0.004). There was no difference in hospital or intensive care unit length of stay between the propofol and etomidate groups (7.7 vs. 9.2 days, p = 0.23;4.2 vs. 6.3 days, p = 0.31). Conclusion: Propofol was a safe and procedurally effective induction agent for RSI. Compared to etomidate, it was associated with an increased rate of hypotension within the first hour of intubation, with no difference in the percent of patients that required an intervention.

Etomidate affects the anti-oxidant pathway to protect retinal ganglion cells after optic nerve transection

Our previous studies revealed that etomidate, a non-barbiturate intravenous anesthetic agent, has protective effects on retinal ganglion cells within 7 days after optic nerve transection. Whether this process is related to anti-oxidative stress is not clear. To reveal its mechanism, we established the optic nerve transection injury model by transecting 1 mm behind the left eyeball of adult male Sprague-Dawley rats. The rats received an intraperitoneal injection of etomidate(4 mg/kg) once per day for 7 days. The results showed that etomidate significantly enhanced the number of retinal ganglion cells retrogradely labeled with Fluorogold at 7 days after optic nerve transection. Etomidate also significantly reduced the levels of nitric oxide and malonaldehyde in the retina and increased the level of glutathione at 12 hours after optic nerve transection. Thus, etomidate can protect retinal ganglion cells after optic nerve transection in adult rats by activating an anti-oxidative stress response. The study was approved by the Animal Ethics Committee at Air Force Medical University, China(approval No. 20180305) on March 5, 2018.

基于ADE优化的IPMSM全速域无传感器控制

为了实现内置式永磁同步电机(IPMSM)全速域的无传感器控制和切换速域的平滑过渡,提出了一种基于自适应差分进化(ADE)算法优化的复合控制方法。分别在零低速域、中高速域采用旋转高频电压注入法和滑模观测器法来对电机转速和转子位置进行估算,并在切换速域采用基于ADE算法的权重系数优化法来实现上述两种控制方法的平滑切换,从而实现IPMSM全速域无传感器控制。仿真结果表明:提出的复合控制方法能够实现电机全速域的无感控制和切换速域的平滑过渡,且具有良好的稳定性。

Etomidate vs propofol in coronary heart disease patients undergoing major noncardiac surgery:A randomized clinical trial

BACKGROUND The ideal depth of general anesthesia should achieve the required levels of hypnosis,analgesia,and muscle relaxation while minimizing physiologic responses to awareness.The choice of anesthetic strategy in patients with coronary heart disease(CHD)undergoing major noncardiac surgery is becoming an increasingly important issue as the population ages.This is because general anesthesia is associated with a risk of perioperative cardiac complications and death,and this risk is much higher in people with CHD.AIM To compare hemodynamic function and cardiovascular event rate between etomidate-and propofol-based anesthesia in patients with CHD.METHODS This prospective study enrolled consecutive patients(American Society of Anesthesiologists grade II/III)with stable CHD(New York Heart Association class I/II)undergoing major noncardiac surgery.The patients were randomly allocated to receive either etomidate/remifentanil-based or propofol/remifentanil-based general anesthesia.Randomization was performed using a computer-generated random number table and sequentially numbered,opaque,sealed envelopes.Concealment was maintained until the patient had arrived in the operating theater,at which point the consulting anesthetist opened the envelope.All patients,data collectors,and data analyzers were blinded to the type of anesthesia used.The primary endpoints were the occurrence of cardiovascular events(bradycardia,tachycardia,hypotension,ST-T segment changes,and ventricular premature beats)during anesthesia and cardiac troponin I level at 24 h.The secondary endpoints were hemodynamic parameters,bispectral index,and use of vasopressors during anesthesia.RESULTS The final analysis included 40 patients in each of the propofol and etomidate groups.The incidences of bradycardia,hypotension,ST-T segment changes,and ventricular premature beats during anesthesia were significantly higher in the propofol group than in the etomidate group(P<0.05 for all).The incidence of tachycardia was similar between the two groups.Cardiac troponin I levels were comparable between the two groups both before the induction of anesthesia and at 24 h after surgery.When compared with the etomidate group,the propofol group had significantly lower heart rates at 3 min after the anesthetic was injected(T1)and immediately after tracheal intubation(T2),lower systolic blood pressure at T1,and lower diastolic blood pressure and mean arterial pressure at T1,T2,3 min after tracheal intubation,and 5 min after tracheal intubation(P<0.05 for all).Vasopressor use was significantly more in the propofol group than in the etomidate group during the induction and maintenance periods(P<0.001).CONCLUSION In patients with CHD undergoing noncardiac major surgery,etomidate-based anesthesia is associated with fewer cardiovascular events and smaller hemodynamic changes than propofol-based anesthesia.

General Anesthesia with Laryngeal Mask Airway: Etomidate VS Propofol for Hemodynamic Stability

Background: Propofol is the most popular induction agent for laryngeal mask airway (LMA) insertion in current anaesthesia practice however associated hypotension has been reported as its major disadvantage. Etomidate, which produces less hypotension, can be considered as an alternative agent for LMA insertion. Objectives: The objective of this study was to compare the hemodynamic effects of etomidate with propofol for induction of general anaesthesia (GA) for LMA. Ease of inserting LMA was also looked at. Material and Methods: It was a prospective randomized double blinded study. All ASA I and II patients of 15 - 60 years of age undergoing general anaesthesia with LMA for elective surgeries were included. Patients were induced with intravenous (I/V) fentanyl and induction agent either etomidate or propofol according to group randomization. LMA was inserted after 30 seconds. Intra-operative heart rate (HR), sys tolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), number of attempts and duration of LMA insertion were monitored. Results: There was no difference in the heart rate between the two groups. A significant drop was found for systolic blood pressure (SBP) in propofol group while diastolic blood pressure (DBP) was decreased in both the groups. In propofol group, successful insertion of LMA was achieved on the first attempt in 93.3% of patient as compared to 36.7% in etomidate group. Conclusion: Use of etomidate for induction of laryngeal mask anesthesia can prevent the hypotension following induction;however it may delay the insertion of laryngeal mask airway.

儿童维生素AD滴剂,这样吃才对

众所周知,维生素A、D对孩子的生长发育至关重要。而补充维生素A、D,最好选择专门的维生素AD制剂,比如维生素AD滴剂。但许多家长对其又不甚了解,有诸多疑问。以下,笔者将一一进行解答。

ADS-B信号在对流层大气波导中的传播性能

对流层大气环境存在特殊大气结构“大气波导”,可形成电波超视距传播或产生雷达盲区等。目前,通过雷达、GNSS信号等可以对大气波导进行一定程度的反演探测,但均存在一定的不足。ADS-B信号具有应用范围广、信号密度大、实时性高等特点,为此提出利用ADS-B信号受到不同大气环境影响后能量损耗不同的特点对ADS-B信号与对流层大气环境关联性进行分析研究。以武汉地区ADS-B信号数据为例,基于抛物方程传播理论对路径损耗进行仿真分析,并进行了实验验证。结果表明:ADS-B接收信号与仿真结果存在线性相关性并给出线性表述,为后续利用ADS-B信号反演大气波导提供参考依据。

星基ADS-B系统空天链路的建模与仿真

星基广播式自动相关监视(ADS-B,automatic dependent surveillance-broadcast)系统是一种新型的航空器监视技术,在未来空中交通管理系统中具有广阔的应用前景。为了深入研究星基ADS-B系统中航空器到卫星的空天链路通信性能,将专业软件Matlab和STK(system tool kit)有效联合,构建符合国际标准的星基ADS-B空天链路完整模型;通过离散事件动态交互模拟ADS-B消息的发送与接收全过程,最后统计得出体现星基ADS-B空天链路通信性能的消息识别概率(POI,possibility of identify)、消息检测概率(POD,possibility of detective)、信号接收功率、信号冲突概率、卫星覆盖范围等指标。仿真结果表明,随着区域内航空器数量上升,POI、POD下降,消息冲突概率上升。

Influence of propofol or etomidate combined with remifentanil in painless gastroscopy on inflammatory stress response

Objective:To study the influence of propofol or etomidate combined with remifentanil in painless gastroscopy on inflammatory stress response.Methods: 117 patients with suspected gastritis who underwent painless gastroscopy in our hospital between July 2015 and August 2016 were divided into propofol group (n=67) and etomidate group (n=50) according to the anesthesia schemes. Propofol group received propofol combined with remifentanil anesthesia, and etomidate group received etomidate combined with remifentanil anesthesia. The differences in serum levels of inflammatory factors, stress hormones and oxidative stress indicators were compared between the two groups before the examination (T0), immediately after the examination (T1) and 15 min after the examination (T2).Results: At T0, there were no significant differences in serum levels of inflammatory factors, stress hormones or oxidative stress indexes between the two groups (P>0.05). At T1 and T2, serum inflammatory factors IL-1, IL-6 and CRP levels of etomidate group were lower than those of propofol group;serum stress hormones Cor, NE and E levels were lower than those of propofol group;serum oxidation indexes AOPPs and LHP levels were lower than those of propofol group while anti-oxidation indexes CAT and SOD levels were higher than those of propofol group (P<0.05). Conclusion: Etomidate for painless gastroscopy is better than propofol in maintaining depth of anesthesia and reducing operation trauma.

Clinical Observation of Dexmedetomidine Combined with the Mixture of Propofol and Etomidate on Painless Gastroscopy in Children

Objective:To observe the anesthetic effect of dexmedetomidine combined with the mixture of propofol and etomidate on painless gastroscopy in children.Methods:A total of 80 pediatric patients who underwent painless gastroscopy in the Guangxi Minzu Hospital from January 2019 to September 2020 were randomly divided into two groups,A and B,with 40 patients in each group.Group A was given A mixture of etomidate 20 mg and propofol 0.2g,Dexmedetomidine was pumped into group B 10min before surgery,0.4 g/kg.HR,SBP,DBP,SpO2 and BIS were continuously monitored after entering the room.The doses of propofol and etomidate were recorded,as well as the time of waking and leaving the hospital.Adverse reactions such as hypotension,hypoxemia,nausea,vomiting and dizziness were recorded too.Results:Compared with group A,the dosage of propofol and etomidate in group B was significantly reduced(P<0.001),the time of waking and out of the chamber were significantly shortened(P<0.001),the body movement in the incidence of intraoperative was significantly reduced(P<0.001),and the nausea,vomiting and dizziness in the incidence of postoperative were significantly reduced(P<0.05).Conclusion:Dexmedetomidine combined with propofol and etomidate mixture can be safely used in painless gastroscopy in children,which can significantly reduce the dosage of propofol and etomidate,reduce the occurrence of adverse reactions,and shorten the time of resuscitation and discharge.

基于ADS-B的雷达测量误差分析方法

本文结合实际工程项目,介绍了广播式自动相关监视(ADS-B)地面接收数据的结构及后续存储、提取方法,同时介绍了雷达数据处理的流程,在此基础上对两路数据进行分析对比,对雷达测量误差进行分析,该方法操作简单,易于实现,且能够满足工程需求。

基于迁移学习-元学习的ADS-B攻击分类研究

准确分类通航领域ADS-B攻击类型,采取预防攻击措施,对保障通航运行安全性具有重要意义。针对通航领域ADS-B攻击数据样本少,提出一种基于迁移学习-元学习的ADS-B攻击分类模型。该模型将迁移学习与深度卷积自编码器相结合,建立ADS-B攻击特征提取模型,提取数据样本的攻击有效特征表示,并运用元学习策略在特征空间中实现ADS-B攻击准确分类。实例研究表明,基于迁移学习-元学习的攻击分类模型可有效分类小样本ADS-B攻击,且正确率在95%以上。

基于迁移学习-元学习的ADS-B攻击分类研究

准确分类通航领域ADS-B攻击类型,采取预防攻击措施,对保障通航运行安全性具有重要意义。针对通航领域ADS-B攻击数据样本少,提出一种基于迁移学习-元学习的ADS-B攻击分类模型。该模型将迁移学习与深度卷积自编码器相结合,建立ADS-B攻击特征提取模型,提取数据样本的攻击有效特征表示,并运用元学习策略在特征空间中实现ADS-B攻击准确分类。实例研究表明,基于迁移学习-元学习的攻击分类模型可有效分类小样本ADS-B攻击,且正确率在95%以上。

[Ca^(2+)]_i change in hippocampal neurons influenced by preconditioning of etomidate fat emulsion following cerebral ischemia in rats

BACKGROUND： It is known that intravenous anesthetic etomidate fat emulsion has cerebral protection. Now many scholars focus on the research of its cerebral protection from molecular biology, but the mechanism of cerebral protection is still fully unclear. OBJECTIVE： To observe the influence of etomidate fat emulsion on the [Ca^2＋]i in hippocampal neurons during the transient cerebral ischemia injury in rats. DESIGN： Randomized controlled observation. SETTING： Weifang Medical College. MATERIALS： This study was carried out in the functional laboratory of Weifang Medical College between October 2005 and March 2006. Twenty-four male healthy Wistar rats, aged 3 to 4 months, were involved. Etomidate fat emulsion was provided by the limited company of En-hua Medical Bloc in Jiangsu Province （code of H200205l l） and the other agents and materials were provided by Laboratory Center of Weifang Medical College. METHODS： The 24 Wistar rats were randomized into 3 groups： sham-operation group, model group and etomidate preconditioning group, with 8 rats in each. Rat models of transient cerebral ischemia injury were made by the ligation of bilateral carotid arteries combined with descending blood pressure in the latter two groups. Before ischemia （ligation of bilateral common carotid artery）, rats in the etomidate preconditioning group were intraperitoneally injected with 12 mg/kg etomidate fat emulsion and then persistently intraperitoneally injected with etomidate fat emulsion at 1.0 mg/kg per minute. Rats in the model group were not administrated. Rats in the sham-operation group were only performed bilateral common carotid artery isolation. When rats were modeled, their brain tissues were quickly taken out and detected. MAIN OUTCOME MEASURES： Change of the fluorescence pixel value of the [Ca^2＋]i in each group by the laser scanning confocal microscope. RESULTS： Twenty-four rats were involved in the final analysis. Fluorescence pixel value in the sham-operation group was in the low level. Fluorescence pixel value in the model group was significantly higher than that in the sham-operation group （P 〈 0.01）. Fluorescence pixel value in the etomidate preconditioning group was significantly lower than that in the model group （P 〈 0.01 ）. CONCLUSION： The protection of etomidate fat emulsion to the transient cerebral ischemic injury in rats is associated with the inhibition to the increase of [Ca^2＋]i to some extent.

Determination of enantiomeric impurity of etomidate by high performance liquid chromatography

Objective To determine enantiomeric impurity of etomidate using high performance liquid chromatography. Methods (R)-etomidate and (S)-etomidate were separated on a CHIRALPAK AD-H column. The mobile phase consisted of 20∶80(v/v) isopropanol-n-hexane. The flow rate of the mobile phase was 0.5mL/min. The detected wavelength was 242nm. Results (R)-etomidate and (S)-etomidate could be separated completely under these conditions. The precision of (R)-etomidate was 1.57% (n=3). The limit of detection of (R)-etomidate was 4.25ng/mL. The average percentage content of (S)-etomidate was 0.09% in the samples. Conclusion The method was repeatable and sufficiently sensitive to determine the enantiomeric impurity of etomidate. It allows the quantitation of the impurities at the 0.085% (w/w) level relative to etomidate at a concentration of the test solution of 5mg/mL.

The Variation in Plasma Cortisol Levels in Response to Anesthetic Induction with Etomidate or Ketamine in Children Undergoing Intracardiac Repair of Tetralogy of Fallot on Cardiopulmonary Bypass

Objective: To compare the effect of a single induction dose of etomidate or ketamine on plasma cortisol levels in children with Tetralogy of Fallot (TOF) undergoing intra-cardiac repair on cardiopulmonary bypass (CPB). Design: A prospective randomized trial. Setting: Cardiac center of a tertiary care hospital. Participants: Thirty children with TOF undergoing intra-cardiac repair on CPB. Interventions: After random allocation of the children into two groups, the children either received etomidate 0.2 mg/kg or ketamine 2 mg/kg intravenously for anesthetic induction along with fentanyl 2 mcg/kg and midazolam 100 mcg/kg. Endotracheal intubation was accomplished with rocuronium bromide in the dose of 1 mg/kg. Anesthesia was maintained with sevoflurane in air-oxygen, titrated to response and supplemental vecuronium bromide for muscle relaxation, fentanyl chloride for pain relief. Serum cortisol was measured on three occasions, at preinduction, at the end of surgery and at 24 hours postoperatively. Measurements and Main Results: Baseline plasma cortisol (Normal 5 - 25 mcg/dl) in the etomidate group (19.91 ± 3.51 mcg/dl) decreased significantly at the end of surgery (5.78 ± 2.0 mcg/dl) and rose to significantly higher than baseline values at 24 hours (27.31 ± 8.30 mcg/dl). The baseline cortisol levels in the ketamine group (20.91 ± 3.19 mcg/dl) increased significantly at the end of surgery (44.02 ± 5.49 mcg/dl) and remained significantly higher than baseline at 24hours (45.93 ± 3.05 mcg/dl). Plasma cortisol levels in the etomidate group at end of surgery, and at 24 hours post-operatively, were significantly lower than the ketamine group. Conclusions: This study shows that etomidate is a suitable and safe agent for suppression of the increase in serum cortisol associated with the use of CPB in children with TOF undergoing intra-cardiac repair.

基于多时间特征融合网络的ADS-B实采信号分离

不同于以往单天线广播式自动相关监视(Automatic Dependent Surveillance-Broadcast,ADS-B)信号分离中利用仿真的ADS-B信号制作数据集,将单天线接收的真实飞机发射的ADS-B原始信号通过调整信号起始时间以及功率并人为增加噪声来制作数据集。为了提高信号分离的时域波形精度,提出一种多分辨率多时间特征融合重采样(Multi-Temporal fusion Resampling of Multi-Resolution Features,MTRM-RF)网络,通过卷积将信号转化成不同采样率的信号并分别使用多层堆叠逐渐膨胀的一维卷积提取不同时间间隔的特征,以获得更多的时间信息。对多种基于深度学习的语音分离网络进行比较发现,MTRM-RF网络能够有效地融合ADS-B信号的不同采样率、不同时间间隔采样点的特征进行训练。并且随着训练集数据量的增加,分离信号的平均解码正确率达到88.39%,证明该网络可有效分离单天线实采的ADS-B交织信号。

The Effects of Etomidate and Propofol Induction on Hemodynamic and Endocrine Response in Patients Undergoing Coronary Artery Bypass Graft Surgery on Cardiopulmonary Bypass

Aim: To compare the effects of propofol and etomidate induction on hemodynamic parameters and serum cortisol levels in patients with normal left ventricular function undergoing elective coronary artery bypass graft surgery on cardiopulmonary bypass. Material and Method: After approval from the Institute Ethics committee hundred American Society of Anesthesiologists (ASA) grade II or III patients undergoing scheduled coronary artery bypass surgery on cardiopulmonary bypass were enrolled in the study. Patients were allocated randomly to receive either propofol or etomidate for anesthesia induction. Anesthesia was maintained in both groups with sevoflurane, vecuronium bromide for muscle relaxation (0.1 mg/kg, boluses) and fentanyl up to a total dose of 20 mcg/kg. Result: The baseline serum cortisol values were within normal limits in both the groups. The serum cortisol levels in the propofol group increased more than two fold, whereas the values in the etomidate group decreased by close to fifty percent on weaning from cardiopulmonary bypass (CPB). There was no significant difference in serum cortisol levels in the two groups at twenty-four hours after induction, although the values were close to double the baseline levels. Hemodynamically, etomidate group was more stable than propofol group following induction of anesthesia (P < 0.05). Conclusion: The surge in serum cortisol levels on the initiation of CPB seen after the use of propofol is prevented by the use of etomidate. Serum cortisol levels in both groups are well above the baseline at twenty-four hours without any untoward effects. Etomidate provides more stable hemodynamic parameters when used for induction of anesthesia as compared to propofol.

Bidirectional regulation of intravenous anes⁃thetic etomidate on TREK-1 potassium channel

OBJECTIVE Two-pore domain potassium channel subtype TREK-1 was widely proved to be activated by inhalational anesthet⁃ics such as chloroform,diethyl ether,halothane,and isoflurane.But little is known about whether TREK-1 was also a potentially important target of intravenous anesthetics.Etomidate is a popularly used intravenous anesthetic with good safety in clinic.The action of etomidate on TREK-1 was seldom reported.METHODS AND RESULTS By using patch-clamp whole-cell recording tech⁃niques,we found for the first time that etomidate could bidirectionally regulate the TREK-1 potassi⁃um channel in CHO/TREK-1 cells.TREK-1 current amplitudes were observed after the administra⁃tion of etomidate at concentrations ranging from 3 to 100μmol·L-1.Etomidate activated TREK-1 current at concentrations of 3,10,and 15μmol·L-1 with maximum activation at 10μmol·L-1.Interest⁃ingly,at higher concentrations from 20 to 100μmol·L-1,etomidate inhibited TREK-1 current in a concentration-dependent way.According to the concentration-response curve,the fitted criti⁃cal concentration of etomidate between TREK-1 activation and inhibition was 20.7μmol·L-1,which close to the result that etomidate had no obvious effect on TREK-1 at 20μmol·L-1.In addition,etomidate 10μmol·L-1 induced a significant mem⁃brane potential hyperpolarization while etomidate 30μmol·L-1 showed obvious membrane potential depolarization.Furthermore,the bidirectional regulation still existed when the extracellular pH of CHO/TREK-1 cells was decreased.CONCLUSION TREK-1 is activated by etomi⁃date at clinically relevant concentrations but inhib⁃ited by supraclinical concentrations of etomidate,which is different to other volatile anesthetics.TREK-1 might be a potential target for anesthetic such as etomidate and the complicated bidirec⁃tional regulation mechanism of etomidate needed to be fully studied in the future.