Desflurane inhibits endothelium-dependent vasodilation more than sevoflurane with inhibition of endothelial nitric oxide synthase by different mechanisms

The effects of desflurane on endothelium-dependent vasodilation remain uncertain, whereas sevoflurane is known to inhibit it. Endothelium-dependent vasodilation is mainly mediated by endothelial nitric oxide synthase. The effects of desflurane on endothelium-dependent vasodilation were compared with those of sevoflurane, and inhibition mechanisms, including phosphorylation of endothelial nitric oxide synthase and the calcium pathway, were evaluated for the two anesthetics. We hypothesized that desflurane would inhibit endothelium-dependent vasodilation in a concentration-dependent manner more than sevoflurane, with inhibition of a calcium pathway.Isolated rat aortic rings were randomly assigned to treatment with desflurane or sevoflurane for measurements of the vasodilation ratio. To determine NO production with desflurane and sevoflurane, an in vitro assay was performed with cultured bovine aortic endothelial cells. These cells were also used for measurement of intracellular calcium or Western blotting.For endothelium-dependent vasodilation, the ratio of vasodilation was more significantly inhibited by 11.4% desflurane than by 4.8% sevoflurane. Inhibition did not between 5.7% desflurane and 2.4% sevoflurane. No inhibitory effect of desflurane or sevoflurane was observed in endothelium-denuded aorta. Desflurane inhibited nitric oxide production caused by stimulation of bradykinin significantly more than sevoflurane. Desflurane had a greater suppressive effect on the bradykinin-induced increase in intracellular calcium concentration than did sevoflurane. Sevoflurane, but not desflurane, inhibited phosphorylation of the serine 1177 residue by bradykinin stimulation.Desflurane inhibited endothelium-dependent vasodilation more than sevoflurane through inhibition of a calcium pathway. Sevoflurane inhibited endothelium-dependent vasodilation by inhibition of phosphorylation of the serine 1177 residue of endothelial nitric oxide synthase.     

麻醉剂七氟烷与地氟烷对患者中性粒细胞和T细胞的影响研究

目的:探讨腹腔手术过程中七氟烷与地氟烷麻醉对患者中性粒细胞和T细胞的影响。方法:随机选取85例年龄在20-60岁的患者,将患者随机分成二组,分别使用七氟烷与地氟烷进行麻醉。在麻醉前30 min和麻醉后2-24 h分别检测患者白细胞、淋巴细胞、中性粒细胞的数量、T辅助淋巴细胞(CD4)、细胞毒性T淋巴细胞(CD8)、自然杀伤性淋巴细胞、激活T淋巴细胞的百分比,CD4/CD8的比值,血浆皮质醇含量。结果:二组患者白细胞与中性粒细胞麻醉24 h后显著升高(P0.01)。地氟烷组中性粒细胞数量显著高于七氟烷组(P0.05)。CD4细胞的百分比在七氟烷组中无显著改变,在麻醉后2h,地氟烷组(31.93%[6.65%])同基础值(36.41%[6.92%])相比显著降低(P0.05),24 h后进一步下降(30.52%[8.01%])(P0.01)。七氟烷组CD4/CD8比值一直无变化,但地氟烷组在麻醉2 h降低(1.51[0.52]),24 h明显升高(1.82[0.72])(P0.05)。结论:与地氟烷相比,七氟烷对中性粒细胞群与T细胞群的影响较小。     

The effect of desflurane on ameliorating cerebral infarction in rats subjected to focal cerebral ischemia-reperfusion injury

To obtain more information on the cerebral ischemia and reperfusion injury under desflurane anesthesia, we compared the infarct volume and lactate dehydrogenase (LDH) activity in rats subjected to focal cerebral ischemia during different concentration of desflurane anesthesia. Male Long-Evans rats weighing 270-350 g were anesthetized with desflurane in air at 1.0, 1.25 or 1.5 MAC whereas rats in the control group received intraperitoneal chloral hydrate (400 mg/kg) anesthesia. Cerebral infarction was induced by microsurgical procedures with ligation of the right middle cerebral artery (MCA) and clipping of the bilateral common carotid arteries (CCA) for 60 minutes. The rats were sacrificed 24 hours later, serial brain slices of 2mm thickness were taken and stained for the measurement of the infarct area. Cellular damage was evaluated by measuring the LDH level in the plasma. Desflurane (1.0, 1.25 or 1.5 MAC by inhalation) and chloral hydrate (400 mg/kg; ip.) did not produce any changes in pH, blood gases, heart rate or mean arterial blood pressure. In the rats subjected to focal cerebral ischemia, the volume of infarction was significantly less in the desflurane groups in all three different concentrations than in the chloral hydrate group. The changes of LDH activity in plasma also correlated with the result of the infarct volume. Our study suggests that desflurane may offer a neuroprotective effect such as decreased infarct volume after focal cerebral ischemia.     

In vivo Imaging of Intact Drosophila Larvae at Sub-cellular Resolution

Recent improvements in optical imaging, genetically encoded fluorophores and genetic tools allowing efficient establishment of desired transgenic animal lines have enabled biological processes to be studied in the context of a living, and in some instances even behaving, organism. In this protocol we will describe how to anesthetize intact Drosophila larvae, using the volatile anesthetic desflurane, to follow the development and plasticity of synaptic populations at sub-cellular resolution^1-3. While other useful methods to anesthetize Drosophila melanogaster larvae have been previously described^4,5,6,7,8, the protocol presented herein demonstrates significant improvements due to the following combined key features: (1) A very high degree of anesthetization; even the heart beat is arrested allowing for lateral resolution of up to 150 nm¹, (2) a high survival rate of > 90% per anesthetization cycle, permitting the recording of more than five time-points over a period of hours to days² and (3) a high sensitivity enabling us in 2 instances to study the dynamics of proteins expressed at physiological levels. In detail, we were able to visualize the postsynaptic glutamate receptor subunit GluR-IIA expressed via the endogenous promoter¹ in stable transgenic lines and the exon trap line FasII-GFP¹. (4) In contrast to other methods^4,7 the larvae can be imaged not only alive, but also intact (i.e. non-dissected) allowing observation to occur over a number of days¹. The accompanying video details the function of individual parts of the in vivo imaging chamber^2,3, the correct mounting of the larvae, the anesthetization procedure, how to re-identify specific positions within a larva and the safe removal of the larvae from the imaging chamber.     

异丙酚联合地氟烷麻醉对颅脑损伤患者脑保护及脑供氧平衡的影响

目的:探讨异丙酚联合地氟烷麻醉对颅脑损伤患者脑保护及脑供氧平衡的影响。方法:选取我院2018年1月至2019年1月接受手术治疗的80例颅脑损伤患者,按照双盲随机原则将入选对象分为研究组和对照组各40例,两组患者采取相同的术前麻醉诱导,术中对照组患者采取异丙酚维持麻醉,研究组患者采取异丙酚联合地氟烷维持麻醉,对比两种麻醉方案对颅脑损伤患者脑保护及脑供氧平衡的影响。结果:研究组患者苏醒时间、定力恢复时间明显短于对照组(P0.05);两组患者诱导前脑氧分压(Pbr O2)对比差异无统计学意义(P0.05),术中及术后,研究组患者PbrO2水平明显高于对照组(P0.05);术毕及术后1 h,研究组患者丙二醛(MDA)、谷氨酸(Glu)均明显低于对照组(P0.05),而血浆超氧化物歧化酶(SOD)明显高于对照组(P0.05);T0时刻,两组患者脑氧摄取率(OER)、动-静脉血氧含量差(Da-jvO2)、脑灌注压(CPP)、平均动脉压(MAP)对比无统计学差异(P0.05),T1-T3时刻,两组患者OER、Da-jvO2、CPP、MAP对比差异有统计学意义(P0.05)。结论:异丙酚联合地氟烷用于颅脑损伤患者的麻醉,具有稳定的麻醉效果,并可保护患者脑组织,维持脑供氧平衡,确保手术顺利开展,且预后效果良好。     

Simultaneous determination of fluorinated inhalation anesthetics in blood by gas chromatography–mass spectrometry combined with a headspace autosampler

Although the fluorinated inhalation anesthetics, including desflurane, sevoflurane, isoflurane, enflurane, and halothane are commonly used, fatal cases resulting from their abuse or misuse have been reported. To date, gas chromatography (GC) equipped with different kinds of detectors has been utilized to analyze inhalation anesthetics. However, none of them can detect desflurane reliably or analyze all five common anesthetics simultaneously. The purpose of the present work is to further modify the previously developed headspace (HS) GC–MS method for blood isoflurane determination to analyze and distinguish five common clinical inhalation anesthetics, simultaneously. The modified HS-GC–MS method adopts a 60 m×0.25 mm I.D., 0.25 μm film thickness DB-5 capillary column along with an adequate GC temperature program, which gives the five inhalation anesthetics, including isoflurane and its isomer, enflurane, a high resolution. The method also takes both the volatility and the influence of the top space on the obtained concentration into consideration and therefore keeps the sample loss acceptable even for analyzing the highly volatile desflurane. Within a certain concentration range of the calibration standard (about 20–300 μg/ml), this method shows a good linearity with correlation coefficients greater than 0.999. In addition, both within- and between-run precision and accuracy results meet the validation requirements as well as the tested results of practical blood samples of desflurane. In summary, this is a reliable analytical method to simultaneously determine the concentration of five common inhalation anesthetics in blood. Such a method is very practical for both clinical and occupational monitoring, as well as for analytical toxicology.