OBJECTIVES: To investigate the regulatory role of astrocytes in the dorsomedial hypothalamus (DMH) during sevoflurane anesthesia emergence. METHODS: Forty-two male C57BL/6 mice were randomized into 6 groups (n=7) for assessing astrocyte activation in the dorsomedial hypothalamus (DMH) under sevoflurane anesthesia. Two groups of mice received microinjection of agfaABC1D promoter-driven AAV2 vector into the DMH for GCaMP6 overexpression, and the changes in astrocyte activity during sevoflurane or air inhalation were recorded using calcium imaging. For assessing optogenetic activation of astrocytes, another two groups of mice received microinjection of an optogenetic virus or a control vector into the DMH with optic fiber implantation, and sevoflurane anesthesia emergence was compared using behavioral experiments. In the remaining two groups, electroencephalogram (EEG) recording during sevoflurane anesthesia emergence was conducted after injection of the hChR2-expressing and control vectors. Anesthesia induction and recovery were assessed by observing the righting reflex. EEG data were recorded under 2.0% sevoflurane to calculate the burst suppression ratio (BSR) and under 1.5% sevoflurane for power spectrum analysis. Immunofluorescence staining was performed to visualize the colocalization of GFAP-positive astrocytes with viral protein signals. RESULTS: Astrocyte activity in the DMH decreased progressively as sevoflurane concentration increased. During 2.0% sevoflurane anesthesia, the mice injected with the ChR2-expressing virus exhibited a significantly shortened wake-up time (P<0.05), and optogenetic activation of the DMH astrocytes led to a marked reduction in BSR (P<0.001). Under 1.5% sevoflurane anesthesia, optogenetic activation resulted in a significant increase in EEG gamma power and a significant decrease in delta power in ChR2 group (P<0.01). CONCLUSIONS Optogenetic activation of DMH astrocytes facilitates sevoflurane anesthesia emergence but does not significantly influence anesthesia induction. These findings offer new insights into the mechanisms underlying anesthesia emergence and may provide a potential target for accelerating postoperative recovery and managing anesthesia-related complications.
Animals ; Astrocytes/physiology* ; Sevoflurane ; Mice, Inbred C57BL ; Mice ; Male ; Electroencephalography ; Anesthetics, Inhalation/pharmacology* ; Hypothalamus/cytology* ; Anesthesia Recovery Period ; Methyl Ethers/pharmacology*

Clinical researches including the Mayo Anesthesia Safety in Kids (MASK) study have found that children undergoing multiple anesthesia may have a higher risk of fine motor control difficulties. However, the underlying mechanisms remain elusive. Here, we report that erythropoietin receptor (EPOR), a microglial receptor associated with phagocytic activity, was significantly downregulated in the medial prefrontal cortex of young mice after multiple sevoflurane anesthesia exposure. Importantly, we found that the inhibited erythropoietin (EPO)/EPOR signaling axis led to microglial polarization, excessive excitatory synaptic pruning, and abnormal fine motor control skills in mice with multiple anesthesia exposure, and those above-mentioned situations were fully reversed by supplementing EPO-derived peptide ARA290 by intraperitoneal injection. Together, the microglial EPOR was identified as a key mediator regulating early synaptic development in this study, which impacted sevoflurane-induced fine motor dysfunction. Moreover, ARA290 might serve as a new treatment against neurotoxicity induced by general anesthesia in clinical practice by targeting the EPO/EPOR signaling pathway.
Animals ; Sevoflurane/toxicity* ; Microglia/drug effects* ; Anesthetics, Inhalation/adverse effects* ; Mice ; Mice, Inbred C57BL ; Receptors, Erythropoietin/metabolism* ; Neuronal Plasticity/drug effects* ; Male ; Prefrontal Cortex/drug effects* ; Erythropoietin/pharmacology* ; Signal Transduction/drug effects*

Anesthetics, Local ; chemistry ; pharmacology ; toxicity ; Central Nervous System ; drug effects ; Ethyl Chloride ; chemistry ; pharmacology ; toxicity ; Humans ; Inhalation ; Male ; Medical History Taking ; Neurologic Examination ; Patient Care Management ; methods ; Psychotropic Drugs ; chemistry ; pharmacology ; toxicity ; Substance-Related Disorders ; etiology ; physiopathology ; psychology ; therapy ; Treatment Outcome ; Volatilization ; Young Adult

Anesthetics, Inhalation ; pharmacology ; Child ; Electrocardiography ; Heart Rate ; drug effects ; Humans ; Isoflurane ; analogs & derivatives ; pharmacology ; Methyl Ethers ; pharmacology

The safety of occupational exposure to inhaled anesthetics remains a concern among the medical staff in hospitals. Few reports are seen about the impact of inhaled anesthetics on the reproductive system, particularly that of males. Several clinical and basic studies on isoflurane and others suggest that inhaled anesthetics affect the reproductive system of rodents by decreasing the sperm count, inducing sperm morphological abnormality, reducing sperm motility, and changing the levels of reproductive hormones, the underlying mechanisms of which are mainly associated with the alteration of the hypothalamic-pituitary-gonadal axis and DNA damage and apoptosis of reproductive cells. This article reviews the main impacts of inhaled anesthetics on the male reproductive system and the possible mechanisms.
Anesthetics, Inhalation ; pharmacology ; Apoptosis ; DNA Damage ; Genitalia, Male ; drug effects ; Humans ; Isoflurane ; pharmacology ; Male ; Occupational Exposure ; Sperm Count ; Sperm Motility ; drug effects ; Spermatozoa ; drug effects

OBJECTIVEAnesthetic isoflurane plus surgery has been reported to induce cognitive impairment. The underlying mechanism and targeted intervention remain largely to be determined. Ginsenoside Rb1 was reported to be neuroprotective. We therefore set out to determine whether ginsenoside Rb1 can attenuate isoflurane/surgery-induced cognitive dysfunction via inhibiting neuroinflammation and oxidative stress.

METHODSFive-months-old C57BL/6J female mice were treated with 1.4% isoflurane plus abdominal surgery for two hours. Sixty mg/kg ginsenoside Rb1 were given intraperitoneally from 7 days before surgery. Cognition of the mice were assessed by Barnes Maze. Levels of postsynaptic density-95 and synaptophysin in mice hippocampus were measured by Western blot. Levels of reactive oxygen species, tumor necrosis factor-α and interleukin-6 in mice hippocampus were measured by ELISA.

RESULTSHere we show for the first time that the ginsenoside Rb1 treatment attenuated the isoflurane/surgery-induced cognitive impairment. Moreover, ginsenoside Rb1 attenuated the isoflurane/surgery-induced synapse dysfunction. Finally, ginsenoside Rb1 mitigated the isoflurane/surgery-induced elevation levels of reactive oxygen species, tumor necrosis factor-α and interleukin-6 in the mice hippocampus.

CONCLUSIONThese results suggest that ginsenoside Rb1 may attenuate the isoflurane/surgery-induced cognitive impairment by inhibiting neuroinflammation and oxidative stress pending future studies.

Anesthetics, Inhalation ; adverse effects ; Animals ; Cognition ; Cognitive Dysfunction ; etiology ; prevention & control ; Female ; Ginsenosides ; pharmacology ; Hippocampus ; drug effects ; Inflammation ; etiology ; prevention & control ; Isoflurane ; adverse effects ; Medicine, Chinese Traditional ; Mice ; Mice, Inbred C57BL ; Oxidative Stress ; Postoperative Complications ; etiology ; prevention & control ; Random Allocation ; Surgical Procedures, Operative ; adverse effects ; Synapses ; metabolism

PURPOSE: Mentally disabled patients show different recovery profiles compared to normal patients after general anesthesia. However, the relationship of dose-recovery profiles of mentally disabled patients has never been compared to that of normal patients. MATERIALS AND METHODS: Twenty patients (10 mentally disabled patients and 10 mentally intact patients) scheduled to dental surgery under general anesthesia was recruited. Sevoflurane was administered to maintain anesthesia during dental treatment. At the end of the surgery, sevoflurane was discontinued. End-tidal sevoflurane and recovery of consciousness (ROC) were recorded after sevoflurane discontinuation. The pharmacodynamic relation between the probability of ROC and end-tidal sevoflurane concentration was analyzed using NONMEM software (version VII). RESULTS: End-tidal sevoflurane concentration associated with 50% probability of ROC (C50) and gamma value were lower in the mentally disabled patients (C50=0.37 vol %, gamma=16.5 in mentally intact patients, C50=0.19 vol %, gamma=4.58 in mentally disabled patients). Mentality was a significant covariate of C50 for ROC and gamma value to pharmacodynamic model. CONCLUSION: A sigmoid Emanx model explains the pharmacodynamic relationship between end-tidal sevoflurane concentration and ROC. Mentally disabled patients may recover slower from anesthesia at lower sevoflurane concentration at ROC an compared to normal patients.
*Anesthesia Recovery Period ; Anesthesia, Dental/*methods ; Anesthesia, General/*methods ; Anesthetics, Inhalation/*administration & dosage/pharmacology ; Case-Control Studies ; Child ; Child, Preschool ; Consciousness/drug effects ; Dental Care for Disabled/*methods ; Dose-Response Relationship, Drug ; Female ; Humans ; Male ; Mentally Disabled Persons ; Methyl Ethers/*administration & dosage/pharmacology

PURPOSE: This study aims to investigate the most appropriate effect-site concentration of remifentanil to minimize cardiovascular changes during inhalation of high concentration desflurane. MATERIALS AND METHODS: Sixty-nine American Society of Anesthesiologists physical status class I patients aged 20-65 years were randomly allocated into one of three groups. Anesthesia was induced with etomidate and rocuronium. Remifentanil was infused at effect-site concentrations of 2, 4 and 6 ng/mL in groups R2, R4 and R6, respectively. After target concentrations of remifentanil were reached, desflurane was inhaled to maintain the end-tidal concentration of 1.7 minimum alveolar concentrations for 5 minutes (over-pressure paradigm). The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR) and end-tidal concentration of desflurane were measured for 5 minutes. RESULTS: The end-tidal concentration of desflurane increased similarly in all groups. The SBP, DBP, MAP and HR within group R4 were not significantly different as compared with baseline values. However, measured parameters within group R2 increased significantly 1-3 minutes after desflurane inhalation. The MAP within group R6 decreased significantly at 1, 2, 4, and 5 minutes (p<0.05). There were significant differences in SBP, DBP, MAP and HR among the three groups 1-3 minutes after inhalation (p<0.05). The incidence of side effects such as hyper- or hypo-tension, and tachy- or brady-cardia in group R4 was 4.8% compared with 21.8% in group R2 and 15.0% in group R6. CONCLUSION: The most appropriate effect-site concentration of remifentanil for blunting hemodynamic responses by inhalation of high concentration desflurane is 4 ng/mL.
Adult ; Aged ; Androstanols/adverse effects/pharmacology ; Anesthetics/adverse effects/pharmacology ; Anesthetics, Inhalation/adverse effects/*pharmacology ; Blood Pressure/drug effects ; Etomidate/adverse effects/pharmacology ; Female ; Heart/*drug effects ; Heart Rate/drug effects ; Humans ; Isoflurane/adverse effects/*analogs & derivatives/pharmacology ; Male ; Middle Aged ; Piperidines/adverse effects/*therapeutic use ; Protective Agents/adverse effects/*therapeutic use

BACKGROUNDVolatile anesthetics (VAs) may affect varied and complex physiology processes by manipulating Ca(2+)-calmodulin (CaM). However, the detailed mechanism about the action of VAs on CaM has not been elucidated. This study was undertaken to examine the effects of VAs on the conformational change, hydrophobic site, and downstream signaling pathway of CaM, to explore the possible mechanism of anesthetic action of VAs.

METHODSReal-time second-harmonic generation (SHG) was performed to monitor the conformational change of CaM in the presence of VAs, each plus 100 µmol/L Ca(2+). A hydrophobic fluorescence indicator, 8-anilinonaphthalene-1-sulfonate (ANS), was utilized to define whether the VAs would interact with CaM at the hydrophobic site or not. High-performance liquid chromatography (HPLC) was carried out to analyze the activity of CaM-dependent phosphodiesterase (PDE1) in the presence of VAs. The VAs studied were ether, enflurane, isoflurane, and sevoflurane, with their aqueous concentrations 7.6, 9.5, 11.4 mmol/L; 0.42, 0.52, 0.62 mmol/L; 0.25, 0.31, 0.37 mmol/L and 0.47, 0.59, 0.71 mmol/L respectively, each were equivalent to their 0.8, 1.0 and 1.2 concentration for 50% of maximal effect (EC50) for general anesthesia.

RESULTSThe second-harmonic radiation of CaM in the presence of Ca(2+) was largely inhibited by the VAs. The fluorescence intensity of ANS, generated by binding of Ca(2+) to CaM, was reversed by the VAs. HPLC results also showed that AMP, the product of the hydrolysis of cAMP by CaM-dependent PDE1, was reduced by the VAs.

CONCLUSIONSOur findings demonstrate that the above VAs interact with the hydrophobic core of Ca(2+)-CaM and the interaction results in the inhibition of the conformational change and activity of CaM. This in vitro study may provide us insight into the possible mechanism of anesthetic action of VAs in vivo.

Adenosine Monophosphate ; analysis ; Anesthetics, Inhalation ; pharmacology ; Anilino Naphthalenesulfonates ; Calmodulin ; antagonists & inhibitors ; chemistry ; physiology ; Cyclic Nucleotide Phosphodiesterases, Type 1 ; analysis ; Fluorescence ; Humans ; Hydrophobic and Hydrophilic Interactions

OBJECTIVETo investigate whether inhaled sevoflurane is capable of producing delayed cardioprotection effect in rats and its underlying mechanisms.

METHODSMale Sprague-Dawley rats inhaled 1.0 minimum alveolar concentration (MAC) sevoflurane, 1.5 MAC sevoflurane,or O(2) for 1 h. After 24 h and 48 h the left coronary artery of rats was occluded for 30 min,followed by 120 min of reperfusion. Hemodynamics was continuously recorded and myocardial infarct size was determined by Evans blue and triphenyltetrazolium chloride staining. The expression of nitric oxide synthase (NOS) was assessed by immunoblotting.

RESULTS1.0 MAC sevoflurane and 1.5 MAC sevoflurane improved cardiac pump function after reperfusion and reduced myocardial infarct size with the increased iNOS expression (P<0.05). However,the expression of eNOS and p-eNOS was not affected (P>0.05). A selective iNOS inhibitor 1400 W abolished the cardioprotection effect induced by inhalation of 1.0 MAC sevoflurane for 24 h.

CONCLUSIONSevoflurane produces delayed cardioprotection through the up-regulation of iNOS expression.

Anesthetics, Inhalation ; pharmacology ; Animals ; Disease Models, Animal ; Ischemic Preconditioning, Myocardial ; Male ; Methyl Ethers ; pharmacology ; Myocardial Reperfusion Injury ; enzymology ; pathology ; prevention & control ; Myocardium ; enzymology ; pathology ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley ; Up-Regulation ; drug effects