1
|
Yeung J, Jhanji S, Braun J, Dunn J, Eggleston L, Frempong S, Hiller L, Jacques C, Jefford M, Mason J, Moonesinghe R, Pearse R, Shelley B, Vindrola C. Volatile vs Total intravenous Anaesthesia for major non-cardiac surgery: a pragmatic randomised triaL (VITAL). Trials 2024; 25:414. [PMID: 38926770 PMCID: PMC11210167 DOI: 10.1186/s13063-024-08159-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Accepted: 05/07/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND Improving outcomes after surgery is a major public health research priority for patients, clinicians and the NHS. The greatest burden of perioperative complications, mortality and healthcare costs lies amongst the population of patients aged over 50 years who undergo major non-cardiac surgery. The Volatile vs Total Intravenous Anaesthesia for major non-cardiac surgery (VITAL) trial specifically examines the effect of anaesthetic technique on key patient outcomes: quality of recovery after surgery (quality of recovery after anaesthesia, patient satisfaction and major post-operative complications), survival and patient safety. METHODS A multi-centre pragmatic efficient randomised trial with health economic evaluation comparing total intravenous anaesthesia with volatile-based anaesthesia in adults (aged 50 and over) undergoing elective major non-cardiac surgery under general anaesthesia. DISCUSSION Given the very large number of patients exposed to general anaesthesia every year, even small differences in outcome between the two techniques could result in substantial excess harm. Results from the VITAL trial will ensure patients can benefit from the very safest anaesthesia care, promoting an early return home, reducing healthcare costs and maximising the health benefits of surgical treatments. TRIAL REGISTRATION ISRCTN62903453. September 09, 2021.
Collapse
Affiliation(s)
- Joyce Yeung
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK.
| | | | - John Braun
- The Royal Marsden NHS Foundation Trust, London, UK
| | - Janet Dunn
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK
| | - Lucy Eggleston
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK
| | - Samuel Frempong
- Centre for Health Economics at Warwick, Warwick Medical School, University of Warwick, Coventry, UK
| | - Louise Hiller
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK
| | - Claire Jacques
- Warwick Clinical Trials Unit, Warwick Medical School, University of Warwick, Coventry, UK
| | | | - James Mason
- Centre for Health Economics at Warwick, Warwick Medical School, University of Warwick, Coventry, UK
| | | | | | | | | |
Collapse
|
2
|
Jin N, Xue Z. Benefits of remimazolam as an anesthetic sedative for older patients: A review. Heliyon 2024; 10:e25399. [PMID: 38370247 PMCID: PMC10867616 DOI: 10.1016/j.heliyon.2024.e25399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/25/2024] [Accepted: 01/25/2024] [Indexed: 02/20/2024] Open
Abstract
Owing to the decreased levels of receptors in the peripheral and central nervous systems, the functions of various organ systems decline in older patients. When administering anesthesia to older patients, it is necessary to consider the effects of medication on the homeostatic balance. Remimazolam, a new benzodiazepine, was recently developed as an anesthetic drug that has shown promise in clinical anesthesia application owing to its molecular structure, targets, pharmacodynamics, and pharmacokinetic characteristics. Remimazolam exhibits a rapid onset and metabolism, with minor effects on liver and kidney functions. Moreover, the drug has a specific antagonist, flumazenil. It is safer to use in older patients than other anesthetic sedatives and has been widely used since its introduction. Comparisons of the pharmacokinetics, metabolic pathways, effects on target organs, and hemodynamics of different drugs with those of commonly used anesthetic sedative drugs are useful to inform clinical practice. This article elaborates on the benefits of remimazolam compared with those of other anesthetic sedatives for sedation in older patients to demonstrate how it offers a new option for anesthetics in older patients. In cases involving older patients with increased clinical complexities or very old patients requiring anesthesia, remimazolam can be selected as the preferred anesthetic sedative, as outlined in this review.
Collapse
Affiliation(s)
- Ning Jin
- Department of Anesthesiology, Benxi Central Hospital, Benxi, 117000, Liaoning Province, China
| | - Zhiqiang Xue
- Department of Anesthesiology, Benxi Central Hospital, Benxi, 117000, Liaoning Province, China
| |
Collapse
|
3
|
Mao LM, Thallapureddy K, Wang JQ. Effects of propofol on presynaptic synapsin phosphorylation in the mouse brain in vivo. Brain Res 2024; 1823:148671. [PMID: 37952872 PMCID: PMC10806815 DOI: 10.1016/j.brainres.2023.148671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 10/24/2023] [Accepted: 11/07/2023] [Indexed: 11/14/2023]
Abstract
The commonly used general anesthetic propofol can enhance the γ-aminobutyric acid-mediated inhibitory synaptic transmission and depress the glutamatergic excitatory synaptic transmission to achieve general anesthesia and other outcomes. In addition to the actions at postsynaptic sites, the modulation of presynaptic activity by propofol is thought to contribute to neurophysiological effects of the anesthetic, although potential targets of propofol within presynaptic nerve terminals are incompletely studied at present. In this study, we explored the possible linkage of propofol to synapsins, a family of neuron-specific phosphoproteins which are the most abundant proteins on presynaptic vesicles, in the adult mouse brain in vivo. We found that an intraperitoneal injection of propofol at a dose that caused loss of righting reflex increased basal levels of synapsin phosphorylation at the major representative phosphorylation sites (serine 9, serine 62/67, and serine 603) in the prefrontal cortex (PFC) of male and female mice. Propofol also elevated synapsin phosphorylation at these sites in the striatum and S9 and S62/67 phosphorylation in the hippocampus, while propofol had no effect on tyrosine hydroxylase phosphorylation in striatal nerve terminals. Total synapsin protein expression in the PFC, hippocampus, and striatum was not altered by propofol. These results reveal that synapsin could be a novel substrate of propofol in the presynaptic neurotransmitter release machinery. Propofol possesses the ability to upregulate synapsin phosphorylation in broad mouse brain regions.
Collapse
Affiliation(s)
- Li-Min Mao
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - Khyathi Thallapureddy
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA
| | - John Q Wang
- Department of Biomedical Sciences, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA; Department of Anesthesiology, School of Medicine, University of Missouri-Kansas City, Kansas City, MO 64108, USA.
| |
Collapse
|
4
|
Simpson BK, Rangwani R, Abbasi A, Chung JM, Reed CM, Gulati T. Disturbed laterality of non-rapid eye movement sleep oscillations in post-stroke human sleep: a pilot study. Front Neurol 2023; 14:1243575. [PMID: 38099067 PMCID: PMC10719949 DOI: 10.3389/fneur.2023.1243575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 11/08/2023] [Indexed: 12/17/2023] Open
Abstract
Sleep is known to promote recovery post-stroke. However, there is a paucity of data profiling sleep oscillations in the post-stroke human brain. Recent rodent work showed that resurgence of physiologic spindles coupled to sleep slow oscillations (SOs) and concomitant decrease in pathological delta (δ) waves is associated with sustained motor performance gains during stroke recovery. The goal of this study was to evaluate bilaterality of non-rapid eye movement (NREM) sleep-oscillations (namely SOs, δ-waves, spindles, and their nesting) in post-stroke patients vs. healthy control subjects. We analyzed NREM-marked electroencephalography (EEG) data in hospitalized stroke-patients (n = 5) and healthy subjects (n = 3). We used a laterality index to evaluate symmetry of NREM oscillations across hemispheres. We found that stroke subjects had pronounced asymmetry in the oscillations, with a predominance of SOs, δ-waves, spindles, and nested spindles in affected hemisphere, when compared to the healthy subjects. Recent preclinical work classified SO-nested spindles as restorative post-stroke and δ-wave-nested spindles as pathological. We found that the ratio of SO-nested spindles laterality index to δ-wave-nested spindles laterality index was lower in stroke subjects. Using linear mixed models (which included random effects of concurrent pharmacologic drugs), we found large and medium effect size for δ-wave nested spindle and SO-nested spindle, respectively. Our results in this pilot study indicate that considering laterality index of NREM oscillations might be a useful metric for assessing recovery post-stroke and that factoring in pharmacologic drugs may be important when targeting sleep modulation for neurorehabilitation post-stroke.
Collapse
Affiliation(s)
- Benjamin K. Simpson
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Rohit Rangwani
- Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Bioengineering Graduate Program, Department of Bioengineering, Henry Samueli School of Engineering, University of California, Los Angeles, Los Angeles, CA, United States
| | - Aamir Abbasi
- Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Jeffrey M. Chung
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Chrystal M. Reed
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
| | - Tanuj Gulati
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Department of Biomedical Sciences, Center for Neural Science and Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, United States
- Bioengineering Graduate Program, Department of Bioengineering, Henry Samueli School of Engineering, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
5
|
Simpson BK, Rangwani R, Abbasi A, Chung JM, Reed CM, Gulati T. Disturbed laterality of non-rapid eye movement sleep oscillations in post-stroke human sleep: a pilot study. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.05.01.23289359. [PMID: 37205348 PMCID: PMC10187327 DOI: 10.1101/2023.05.01.23289359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Sleep is known to promote recovery post-stroke. However, there is a paucity of data profiling sleep oscillations post-stroke in the human brain. Recent rodent work showed that resurgence of physiologic spindles coupled to sleep slow oscillations(SOs) and concomitant decrease in pathological delta(δ) waves is associated with sustained motor performance gains during stroke recovery. The goal of this study was to evaluate bilaterality of non-rapid eye movement (NREM) sleep-oscillations (namely SOs, δ-waves, spindles and their nesting) in post-stroke patients versus healthy control subjects. We analyzed NREM-marked electroencephalography (EEG) data in hospitalized stroke-patients (n=5) and healthy subjects (n=3) from an open-sourced dataset. We used a laterality index to evaluate symmetry of NREM oscillations across hemispheres. We found that stroke subjects had pronounced asymmetry in the oscillations, with a predominance of SOs, δ-waves, spindles and nested spindles in one hemisphere, when compared to the healthy subjects. Recent preclinical work classified SO-nested spindles as restorative post-stroke and δ-wave-nested spindles as pathological. We found that the ratio of SO-nested spindles laterality index to δ-wave-nested spindles laterality index was lower in stroke subjects. Using linear mixed models (which included random effects of concurrent pharmacologic drugs), we found large and medium effect size for δ-wave nested spindle and SO-nested spindle, respectively. Our results indicate considering laterality index of NREM oscillations might be a useful metric for assessing recovery post-stroke and that factoring in pharmacologic drugs may be important when targeting sleep modulation for neurorehabilitation post-stroke.
Collapse
Affiliation(s)
| | - Rohit Rangwani
- Center for Neural Science and Medicine, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
- Bioengineering Graduate Program, Department of Bioengineering, Henry Samueli School of Engineering, University of California - Los Angeles, Los Angeles, CA
| | - Aamir Abbasi
- Center for Neural Science and Medicine, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Jeffrey M Chung
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Chrystal M Reed
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Tanuj Gulati
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA
- Center for Neural Science and Medicine, Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA
- Bioengineering Graduate Program, Department of Bioengineering, Henry Samueli School of Engineering, University of California - Los Angeles, Los Angeles, CA
- Department of Medicine, David Geffen School of Medicine, University of California-Los Angeles, Los Angeles, CA
| |
Collapse
|
6
|
Pence A, Hoyt H, McGrath M, Forman SA, Raines DE. Competitive Interactions Between Propofol and Diazepam: Studies in GABA A Receptors and Zebrafish. J Pharmacol Exp Ther 2022; 383:238-245. [PMID: 36167415 PMCID: PMC9667980 DOI: 10.1124/jpet.122.001337] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 08/25/2022] [Accepted: 09/16/2022] [Indexed: 01/07/2023] Open
Abstract
Although propofol is among the most commonly administered general anesthetics, its mechanism of action is not fully understood. It has been hypothesized that propofol acts via a similar mechanism as (R)-ethyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate (etomidate) by binding within the GABAA receptor transmembrane receptor domain at the two β +/α - subunit interfaces with resultant positive allosteric modulation. To test this hypothesis, we leveraged the ability of diazepam to bind to those sites and act as a competitive antagonist. We used oocyte-expressed α 1 β 3 γ 2L GABAA receptors to define the actions of diazepam (± flumazenil) on currents activated or potentiated by propofol and a zebrafish activity assay to define the impact of diazepam and flumazenil on propofol-induced anesthesia. We found that diazepam increased the amplitudes of GABAA receptor-mediated currents at nanomolar concentrations but reduced them at micromolar concentrations. The current amplitude changes produced by nanomolar diazepam concentrations were inhibited by flumazenil whereas those produced by micromolar diazepam concentrations were not. Studies of agonist potentiation showed that the micromolar inhibitory action of diazepam was surmountable by high concentrations of propofol and produced a rightward shift in the propofol concentration-response curve characterized by a Schild slope not statistically significantly different from 1, consistent with competition between diazepam and propofol. Although micromolar concentrations of diazepam (plus flumazenil) similarly reduced GABAA receptor currents modulated by propofol and etomidate, it only reduced the anesthetic actions of etomidate. We conclude that while both propofol and etomidate can modulate GABAA receptors by binding to the β +/α - subunit interfacial sites, propofol-induced anesthesia likely involves additional target sites. SIGNIFICANCE STATEMENT: Although the drug combination of diazepam and flumazenil reverses the GABAA receptor positive modulatory actions of both propofol and (R)-ethyl 1-(1-phenylethyl)-1H-imidazole-5-carboxylate (etomidate), it only reverses the in vivo anesthetic actions of etomidate. These results strongly suggest that distinct mechanisms of action account for the anesthetic actions of these two commonly administered anesthetic agents.
Collapse
Affiliation(s)
- Andrea Pence
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Helen Hoyt
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Megan McGrath
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Stuart A Forman
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Douglas E Raines
- Department of Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts
| |
Collapse
|
7
|
Frank M, Nabb AT, Gilbert SP, Bentley M. Propofol attenuates kinesin-mediated axonal vesicle transport and fusion. Mol Biol Cell 2022; 33:ar119. [PMID: 36103253 PMCID: PMC9634964 DOI: 10.1091/mbc.e22-07-0276] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Propofol is a widely used general anesthetic, yet the understanding of its cellular effects is fragmentary. General anesthetics are not as innocuous as once believed and have a wide range of molecular targets that include kinesin motors. Propofol, ketamine, and etomidate reduce the distances that Kinesin-1 KIF5 and Kinesin-2 KIF3 travel along microtubules in vitro. These transport kinesins are highly expressed in the CNS, and their dysfunction leads to a range of human pathologies including neurodevelopmental and neurodegenerative diseases. While in vitro data suggest that general anesthetics may disrupt kinesin transport in neurons, this hypothesis remains untested. Here we find that propofol treatment of hippocampal neurons decreased vesicle transport mediated by Kinesin-1 KIF5 and Kinesin-3 KIF1A ∼25-60%. Propofol treatment delayed delivery of the KIF5 cargo NgCAM to the distal axon. Because KIF1A participates in axonal transport of presynaptic vesicles, we tested whether prolonged propofol treatment affects synaptic vesicle fusion mediated by VAMP2. The data show that propofol-induced transport delay causes a significant decrease in vesicle fusion in distal axons. These results are the first to link a propofol-induced delay in neuronal trafficking to a decrease in axonal vesicle fusion, which may alter physiological function during and after anesthesia.
Collapse
Affiliation(s)
- Madeline Frank
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Alec T. Nabb
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Susan P. Gilbert
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180
| | - Marvin Bentley
- Department of Biological Sciences and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180,*Address correspondence to: Marvin Bentley ()
| |
Collapse
|
8
|
Distinct effects of volatile and intravenous anaesthetics on presynaptic calcium dynamics in mouse hippocampal GABAergic neurones. Br J Anaesth 2022; 128:1019-1028. [DOI: 10.1016/j.bja.2022.01.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 01/04/2022] [Accepted: 01/07/2022] [Indexed: 12/22/2022] Open
|
9
|
Kir Channel Molecular Physiology, Pharmacology, and Therapeutic Implications. Handb Exp Pharmacol 2021; 267:277-356. [PMID: 34345939 DOI: 10.1007/164_2021_501] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
For the past two decades several scholarly reviews have appeared on the inwardly rectifying potassium (Kir) channels. We would like to highlight two efforts in particular, which have provided comprehensive reviews of the literature up to 2010 (Hibino et al., Physiol Rev 90(1):291-366, 2010; Stanfield et al., Rev Physiol Biochem Pharmacol 145:47-179, 2002). In the past decade, great insights into the 3-D atomic resolution structures of Kir channels have begun to provide the molecular basis for their functional properties. More recently, computational studies are beginning to close the time domain gap between in silico dynamic and patch-clamp functional studies. The pharmacology of these channels has also been expanding and the dynamic structural studies provide hope that we are heading toward successful structure-based drug design for this family of K+ channels. In the present review we focus on placing the physiology and pharmacology of this K+ channel family in the context of atomic resolution structures and in providing a glimpse of the promising future of therapeutic opportunities.
Collapse
|
10
|
Nourski KV, Steinschneider M, Rhone AE, Krause BM, Mueller RN, Kawasaki H, Banks MI. Cortical Responses to Vowel Sequences in Awake and Anesthetized States: A Human Intracranial Electrophysiology Study. Cereb Cortex 2021; 31:5435-5448. [PMID: 34117741 PMCID: PMC8568007 DOI: 10.1093/cercor/bhab168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/22/2021] [Accepted: 05/22/2021] [Indexed: 02/07/2023] Open
Abstract
Elucidating neural signatures of sensory processing across consciousness states is a major focus in neuroscience. Noninvasive human studies using the general anesthetic propofol reveal differential effects on auditory cortical activity, with a greater impact on nonprimary and auditory-related areas than primary auditory cortex. This study used intracranial electroencephalography to examine cortical responses to vowel sequences during induction of general anesthesia with propofol. Subjects were adult neurosurgical patients with intracranial electrodes placed to identify epileptic foci. Data were collected before electrode removal surgery. Stimuli were vowel sequences presented in a target detection task during awake, sedated, and unresponsive states. Averaged evoked potentials (AEPs) and high gamma (70-150 Hz) power were measured in auditory, auditory-related, and prefrontal cortex. In the awake state, AEPs were found throughout studied brain areas; high gamma activity was limited to canonical auditory cortex. Sedation led to a decrease in AEP magnitude. Upon LOC, there was a decrease in the superior temporal gyrus and adjacent auditory-related cortex and a further decrease in AEP magnitude in core auditory cortex, changes in the temporal structure and increased trial-to-trial variability of responses. The findings identify putative biomarkers of LOC and serve as a foundation for future investigations of altered sensory processing.
Collapse
Affiliation(s)
- Kirill V Nourski
- Address correspondence to Kirill V. Nourski, MD, PhD, Department of Neurosurgery, The University of Iowa, 200 Hawkins Dr. 1815 JCP, Iowa City, IA 52242, USA.
| | - Mitchell Steinschneider
- Department of Neurology and Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Ariane E Rhone
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA
| | - Bryan M Krause
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| | - Rashmi N Mueller
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA,Department of Anesthesia, The University of Iowa, Iowa City, IA 52242, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, The University of Iowa, Iowa City, IA 52242, USA
| | - Matthew I Banks
- Department of Anesthesiology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA,Department of Neuroscience, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
| |
Collapse
|
11
|
Kell DB. A protet-based, protonic charge transfer model of energy coupling in oxidative and photosynthetic phosphorylation. Adv Microb Physiol 2021; 78:1-177. [PMID: 34147184 DOI: 10.1016/bs.ampbs.2021.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Textbooks of biochemistry will explain that the otherwise endergonic reactions of ATP synthesis can be driven by the exergonic reactions of respiratory electron transport, and that these two half-reactions are catalyzed by protein complexes embedded in the same, closed membrane. These views are correct. The textbooks also state that, according to the chemiosmotic coupling hypothesis, a (or the) kinetically and thermodynamically competent intermediate linking the two half-reactions is the electrochemical difference of protons that is in equilibrium with that between the two bulk phases that the coupling membrane serves to separate. This gradient consists of a membrane potential term Δψ and a pH gradient term ΔpH, and is known colloquially as the protonmotive force or pmf. Artificial imposition of a pmf can drive phosphorylation, but only if the pmf exceeds some 150-170mV; to achieve in vivo rates the imposed pmf must reach 200mV. The key question then is 'does the pmf generated by electron transport exceed 200mV, or even 170mV?' The possibly surprising answer, from a great many kinds of experiment and sources of evidence, including direct measurements with microelectrodes, indicates it that it does not. Observable pH changes driven by electron transport are real, and they control various processes; however, compensating ion movements restrict the Δψ component to low values. A protet-based model, that I outline here, can account for all the necessary observations, including all of those inconsistent with chemiosmotic coupling, and provides for a variety of testable hypotheses by which it might be refined.
Collapse
Affiliation(s)
- Douglas B Kell
- Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative, Biology, University of Liverpool, Liverpool, United Kingdom; The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark.
| |
Collapse
|
12
|
Mechanistic basis of propofol-induced disruption of kinesin processivity. Proc Natl Acad Sci U S A 2021; 118:2023659118. [PMID: 33495322 DOI: 10.1073/pnas.2023659118] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Propofol is a widely used general anesthetic to induce and maintain anesthesia, and its effects are thought to occur through impact on the ligand-gated channels including the GABAA receptor. Propofol also interacts with a large number of proteins including molecular motors and inhibits kinesin processivity, resulting in significant decrease in the run length for conventional kinesin-1 and kinesin-2. However, the molecular mechanism by which propofol achieves this outcome is not known. The structural transition in the kinesin neck-linker region is crucial for its processivity. In this study, we analyzed the effect of propofol and its fluorine derivative (fropofol) on the transition in the neck-linker region of kinesin. Propofol binds at two crucial surfaces in the leading head: one at the microtubule-binding interface and the other in the neck-linker region. We observed in both the cases the order-disorder transition of the neck-linker was disrupted and kinesin lost its signal for forward movement. In contrast, there was not an effect on the neck-linker transition with propofol binding at the trailing head. Free-energy calculations show that propofol at the microtubule-binding surface significantly reduces the microtubule-binding affinity of the kinesin head. While propofol makes pi-pi stacking and H-bond interactions with the propofol binding cavity, fropofol is unable to make a suitable interaction at this binding surface. Therefore, the binding affinity of fropofol is much lower compared to propofol. Hence, this study provides a mechanism by which propofol disrupts kinesin processivity and identifies transitions in the ATPase stepping cycle likely affected.
Collapse
|
13
|
White ER, Leace DM, Bedell VM, Bhanu NV, Garcia BA, Dailey WP, Eckenhoff RG. Synthesis and Characterization of a Diazirine-Based Photolabel of the Nonanesthetic Fropofol. ACS Chem Neurosci 2021; 12:176-183. [PMID: 33355437 PMCID: PMC7948515 DOI: 10.1021/acschemneuro.0c00667] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mechanisms of general anesthetics have been debated in the literature for many years and continue to be of great interest. As anesthetic molecules are notoriously difficult to study due to their low binding affinities and multitude of binding partners, it is advantageous to have additional tools to study these interactions. Fropofol is a hydroxyl to fluorine-substituted propofol analogue that is able to antagonize the actions of propofol. Understanding fropofol's ability to antagonize propofol would facilitate further characterization of the binding interactions of propofol that may contribute to its anesthetic actions. However, the study of fropofol's molecular interactions has many of the same difficulties as its parent compound. Here, we present the synthesis and characterization of ortho-azi-fropofol (AziFo) as a suitable photoaffinity label (PAL) of fropofol that can be used to covalently label proteins of interest to characterize fropofol's binding interactions and their contribution to general anesthetic antagonism.
Collapse
Affiliation(s)
- E Railey White
- Perelman School of Medicine, Department of Anesthesiology and Critical Care, University of Pennsylvania, John Morgan Building, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104, United States
| | - David M Leace
- Perelman School of Medicine, Department of Anesthesiology and Critical Care, University of Pennsylvania, John Morgan Building, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104, United States
| | - Victoria M Bedell
- Perelman School of Medicine, Department of Anesthesiology and Critical Care, University of Pennsylvania, John Morgan Building, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104, United States
| | - Natarajan V Bhanu
- Perelman School of Medicine, Department of Biochemistry and Biophysics, Smilow Center for Translational Research, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, United States
| | - Benjamin A Garcia
- Perelman School of Medicine, Department of Biochemistry and Biophysics, Smilow Center for Translational Research, University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, Pennsylvania 19104, United States
| | - William P Dailey
- Department of Chemistry, University of Pennsylvania, 231 S. 34th Street, Philadelphia, Pennsylvania 19104, United States
| | - Roderic G Eckenhoff
- Perelman School of Medicine, Department of Anesthesiology and Critical Care, University of Pennsylvania, John Morgan Building, 3620 Hamilton Walk, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
14
|
Ma J, Peng M, Wang F, Chen L, Zhang ZZ, Wang YL. [Effect of pre-administered flurbiprofen axetil on the EC50 of propofol during anesthesia in unstimulated patients: a randomized clinical trial]. Rev Bras Anestesiol 2020; 70:605-612. [PMID: 33223005 DOI: 10.1016/j.bjan.2020.08.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 08/04/2020] [Accepted: 08/08/2020] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND OBJECTIVES Preoperative use of flurbiprofen axetil (FA) is extensively adopted to modulate the effects of analgesia. However, the relationship between FA and sedation agents remains unclear. In this study, we aimed to investigate the effects of different doses of FA on the median Effective Concentration (EC50) of propofol. METHODS Ninety-six patients (ASA I or II, aged 18-65 years) were randomly assigned into one of four groups in a 1:1:1:1 ratio. Group A (control group) received 10 mL of Intralipid, and groups B, C and D received 0.5 mg.kg-1, 0.75 mg.kg-1 and 1 mg.kg-1 of FA, respectively, 10 minutes before induction. The depth of anesthesia was measured by the Bispectral Index (BIS). The "up-and-down" method was used to calculate the EC50 of propofol. During the equilibration period, if BIS ≤ 50 (or BIS > 50), the next patient would receive a 0.5 μg.mL-1-lower (or-higher) propofol Target-Controlled Infusion (TCI) concentration. The hemodynamic data were recorded at baseline, 10 minutes after FA administration, after induction, after intubation, and 15 minutes after intubation. RESULTS The EC50 of propofol was lower in Group C (2.32 μg.mL-1, 95% Confidence Interval [95% CI] 1.85-2.75) and D (2.39 μg.mL-1, 95% CI 1.91-2.67) than in Group A (2.96 μg.mL-1, 95% CI 2.55-3.33) (p = 0.023, p = 0.048, respectively). There were no significant differences in the EC50 between Group B (2.53 μg.mL-1, 95% CI 2.33-2.71) and Group A (p ˃ 0.05). There were no significant differences in Heart Rate (HR) among groups A, B and C. The HR was significantly lower in Group D than in Group A after intubation (66 ± 6 vs. 80 ± 10 bpm, p < 0.01) and 15 minutes after intubation (61 ± 4 vs. 70 ± 8 bpm, p < 0.01). There were no significant differences among the four groups in Mean Arterial Pressure (MAP) at any time point. The MAP of the four groups was significantly lower after induction, after intubation, and 15 minutes after intubation than at baseline (p < 0.05). CONCLUSION High-dose FA (0.75 mg.kg-1 or 1 mg.kg-1) reduces the EC50 of propofol, and 1 mg.kg-1 FA reduces the HR for adequate anesthesia in unstimulated patients. Although this result should be investigated in cases of surgical stimulation, we suggest that FA pre-administration may reduce the propofol requirement when the depth of anesthesia is measured by BIS.
Collapse
Affiliation(s)
- Jing Ma
- Zhongnan Hospital of Wuhan University, Department of Anesthesiology, Wuhan, China
| | - Mian Peng
- Zhongnan Hospital of Wuhan University, Department of Anesthesiology, Wuhan, China
| | - Fei Wang
- Zhongnan Hospital of Wuhan University, Department of Anesthesiology, Wuhan, China
| | - Lei Chen
- Zhongnan Hospital of Wuhan University, Department of Anesthesiology, Wuhan, China
| | - Zong-Ze Zhang
- Zhongnan Hospital of Wuhan University, Department of Anesthesiology, Wuhan, China
| | - Yan-Lin Wang
- Zhongnan Hospital of Wuhan University, Department of Anesthesiology, Wuhan, China.
| |
Collapse
|
15
|
Bi D, Yang J, Hong JY, Parikh P, Hinds N, Infanti J, Lin H, Weiser BP. Substrate-Dependent Modulation of SIRT2 by a Fluorescent Probe, 1-Aminoanthracene. Biochemistry 2020; 59:3869-3878. [PMID: 32941003 PMCID: PMC7880049 DOI: 10.1021/acs.biochem.0c00564] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Sirtuin isoform 2 (SIRT2) is an enzyme that catalyzes the removal of acyl groups from lysine residues. SIRT2's catalytic domain has a hydrophobic tunnel where its substrate acyl groups bind. Here, we report that the fluorescent probe 1-aminoanthracene (AMA) binds within SIRT2's hydrophobic tunnel in a substrate-dependent manner. AMA's interaction with SIRT2 was characterized by its enhanced fluorescence upon protein binding (>10-fold). AMA interacted weakly with SIRT2 alone in solution (Kd = 37 μM). However, when SIRT2 was equilibrated with a decanoylated peptide substrate, AMA's affinity for SIRT2 was enhanced ∼10-fold (Kd = 4 μM). The peptide's decanoyl chain and AMA co-occupied SIRT2's hydrophobic tunnel when bound to the protein. In contrast, binding of AMA to SIRT2 was competitive with a myristoylated substrate whose longer acyl chain occluded the entire tunnel. AMA competitively inhibited SIRT2 demyristoylase activity with an IC50 of 21 μM, which was significantly more potent than its inhibition of other deacylase activities. Finally, binding and structural analysis suggests that the AMA binding site in SIRT2's hydrophobic tunnel was structurally stabilized when SIRT2 interacted with a decanoylated or 4-oxononanoylated substrate, but AMA's binding site was less stable when SIRT2 was bound to an acetylated substrate. Our use of AMA to explore changes in SIRT2's hydrophobic tunnel that are induced by interactions with specific acylated substrates has implications for developing ligands that modulate SIRT2's substrate specificity.
Collapse
Affiliation(s)
- David Bi
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08084, United States
| | - Jie Yang
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08084, United States
| | - Jun Young Hong
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Prashit Parikh
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08084, United States
| | - Nicole Hinds
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08084, United States
| | - Joseph Infanti
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08084, United States
| | - Hening Lin
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States.,Howard Hughes Medical Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Brian P Weiser
- Department of Molecular Biology, Rowan University School of Osteopathic Medicine, Stratford, New Jersey 08084, United States
| |
Collapse
|
16
|
Hao X, Ou M, Zhang D, Zhao W, Yang Y, Liu J, Yang H, Zhu T, Li Y, Zhou C. The Effects of General Anesthetics on Synaptic Transmission. Curr Neuropharmacol 2020; 18:936-965. [PMID: 32106800 PMCID: PMC7709148 DOI: 10.2174/1570159x18666200227125854] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 01/20/2020] [Accepted: 02/26/2020] [Indexed: 02/08/2023] Open
Abstract
General anesthetics are a class of drugs that target the central nervous system and are widely used for various medical procedures. General anesthetics produce many behavioral changes required for clinical intervention, including amnesia, hypnosis, analgesia, and immobility; while they may also induce side effects like respiration and cardiovascular depressions. Understanding the mechanism of general anesthesia is essential for the development of selective general anesthetics which can preserve wanted pharmacological actions and exclude the side effects and underlying neural toxicities. However, the exact mechanism of how general anesthetics work is still elusive. Various molecular targets have been identified as specific targets for general anesthetics. Among these molecular targets, ion channels are the most principal category, including ligand-gated ionotropic receptors like γ-aminobutyric acid, glutamate and acetylcholine receptors, voltage-gated ion channels like voltage-gated sodium channel, calcium channel and potassium channels, and some second massager coupled channels. For neural functions of the central nervous system, synaptic transmission is the main procedure for which information is transmitted between neurons through brain regions, and intact synaptic function is fundamentally important for almost all the nervous functions, including consciousness, memory, and cognition. Therefore, it is important to understand the effects of general anesthetics on synaptic transmission via modulations of specific ion channels and relevant molecular targets, which can lead to the development of safer general anesthetics with selective actions. The present review will summarize the effects of various general anesthetics on synaptic transmissions and plasticity.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | - Yu Li
- Address correspondence to these authors at the Laboratory of Anesthesia & Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, P.R. China; E-mail: and Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, Sichuan, P.R. China; E-mail:
| | - Cheng Zhou
- Address correspondence to these authors at the Laboratory of Anesthesia & Critical Care Medicine, Translational Neuroscience Center, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, P.R. China; E-mail: and Department of Anesthesiology, West China Hospital of Sichuan University, Chengdu, 610041, Sichuan, P.R. China; E-mail:
| |
Collapse
|
17
|
Population Pharmacodynamics of Propofol and Sevoflurane in Healthy Volunteers Using a Clinical Score and the Patient State Index. Anesthesiology 2019; 131:1223-1238. [DOI: 10.1097/aln.0000000000002966] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Abstract
Editor’s Perspective
What We Already Know about This Topic
What This Article Tells Us That Is New
Background
The population pharmacodynamics of propofol and sevoflurane with or without opioids were compared using the endpoints no response to calling the person by name, tolerance to shake and shout, tolerance to tetanic stimulus, and two versions of a processed electroencephalographic measure, the Patient State Index (Patient State Index-1 and Patient State Index-2).
Methods
This is a reanalysis of previously published data. Volunteers received four anesthesia sessions, each with different drug combinations of propofol or sevoflurane, with or without remifentanil. Nonlinear mixed effects modeling was used to study the relationship between drug concentrations, clinical endpoints, and Patient State Index-1 and Patient State Index-2.
Results
The C50 values for no response to calling the person by name, tolerance to shake and shout, and tolerance to tetanic stimulation for propofol (µg · ml−1) and sevoflurane (vol %; relative standard error [%]) were 1.62 (7.00)/0.64 (4.20), 1.85 (6.20)/0.90 (5.00), and 2.82 (15.5)/0.91 (10.0), respectively. The C50 values for Patient State Index-1 and Patient State Index-2 were 1.63 µg · ml−1 (3.7) and 1.22 vol % (3.1) for propofol and sevoflurane. Only for sevoflurane was a significant difference found in the pharmacodynamic model for Patient State Index-2 compared with Patient State Index-1. The pharmacodynamic models for Patient State Index-1 and Patient State Index-2 as a predictor for no response to calling the person by name, tolerance to shake and shout, and tetanic stimulation were indistinguishable, with Patient State Index50 values for propofol and sevoflurane of 46.7 (5.1)/68 (3.0), 41.5 (4.1)/59.2 (3.6), and 29.5 (12.9)/61.1 (8.1), respectively. Post hoc C50 values for propofol and sevoflurane were perfectly correlated (correlation coefficient = 1) for no response to calling the person by name and tolerance to shake and shout. Post hoc C50 and Patient State Index50 values for propofol and sevoflurane for tolerance to tetanic stimulation were independent within an individual (correlation coefficient = 0).
Conclusions
The pharmacodynamics of propofol and sevoflurane were described on both population and individual levels using a clinical score and the Patient State Index. Patient State Index-2 has an improved performance at higher sevoflurane concentrations, and the relationship to probability of responsiveness depends on the drug used but is unaffected for Patient State Index-1 and Patient State Index-2.
Collapse
|
18
|
Aggarwal A, Brennan C, Shortal B, Contreras D, Kelz MB, Proekt A. Coherence of Visual-Evoked Gamma Oscillations Is Disrupted by Propofol but Preserved Under Equipotent Doses of Isoflurane. Front Syst Neurosci 2019; 13:19. [PMID: 31139058 PMCID: PMC6519322 DOI: 10.3389/fnsys.2019.00019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 04/18/2019] [Indexed: 12/15/2022] Open
Abstract
Previous research demonstrates that the underlying state of the brain influences how sensory stimuli are processed. Canonically, the state of the brain has been defined by quantifying the spectral characteristics of spontaneous fluctuations in local field potentials (LFP). Here, we utilized isoflurane and propofol anesthesia to parametrically alter the spectral state of the murine brain. With either drug, we produce slow wave activity, with low anesthetic doses, or burst suppression, with higher doses. We find that while spontaneous LFP oscillations were similar, the average visual-evoked potential (VEP) was always smaller in amplitude and shorter in duration under propofol than under comparable doses of isoflurane. This diminished average VEP results from increased trial-to-trial variability in VEPs under propofol. One feature of single trial VEPs that was consistent in all animals was visual-evoked gamma band oscillation (20-60 Hz). This gamma band oscillation was coherent between trials in the early phase (<250 ms) of the visual evoked potential under isoflurane. Inter trial phase coherence (ITPC) of gamma oscillations was dramatically attenuated in the same propofol anesthetized mice despite similar spontaneous oscillations in the LFP. This suggests that while both anesthetics lead to loss of consciousness (LOC), elicit slow oscillations and burst suppression, only the isoflurane permits phase resetting of gamma oscillations by visual stimuli. These results demonstrate that accurate characterization of a brain state must include both spontaneous as well as stimulus-induced perturbations of brain activity.
Collapse
Affiliation(s)
- Adeeti Aggarwal
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Connor Brennan
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Brenna Shortal
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Diego Contreras
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Max B Kelz
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Alex Proekt
- Department of Anesthesiology and Critical Care, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States
| |
Collapse
|
19
|
Intravenous Anesthetic Protects Hepatocyte from Reactive Oxygen Species-Induced Cellular Apoptosis during Liver Transplantation In Vivo. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:4780615. [PMID: 30510620 PMCID: PMC6230392 DOI: 10.1155/2018/4780615] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/28/2018] [Indexed: 12/31/2022]
Abstract
Background Liver transplantation leads to liver ischemia/reperfusion (I/R) injury, resulting in early graft dysfunction and failure. Exacerbations of oxidative stress and inflammatory response are key processes in the development of liver I/R injury. Intravenous anesthetic propofol potent effects on free radical scavenging and protects livers against I/R injury. However, the role and mechanism of propofol-mediated hepatic protection in liver transplantation is poorly understood. The aim of this study was to evaluate the role of propofol postconditioning in the liver I/R injury after liver transplantation. Methods Forty-eight rats were randomly divided into six groups: rats receiving either sham operation or orthotopic autologous liver transplantation (OALT) in the absence or presence of propofol (high dose and low dose) postconditioning or intralipid control or VAS2870 (Nox2 special inhibitor). Eight hours after OALT or sham operation, parameters of organ injury, oxidative stress, inflammation, and NADPH-associated proteins were assessed. Results After OALT, severe liver pathological injury was observed that was associated with increases of serum AST and ALT, which were attenuated by propofol postconditioning. In addition, especially high dose of propofol postconditioning reduced TNF-α, IL-1β, IL-6, TLR4, and NF-κB inflammatory pathway, accompanied with decrease of neutrophil elastase activity, MPO activity, 8-isoprotane, p47phox and gp91phox protein expressions, and increase of SOD activity. Inhibition of Nox2 by VAS2870 conferred similar protective effects in liver transplantation. Conclusion Liver transplantation leads to severe inflammation and oxidative stress with NADPH oxidase activation. Propofol postconditioning reduces liver I/R injury after liver transplantation partly via inhibiting NADPH oxidase Nox2 and the subsequent inflammation and oxidative stress.
Collapse
|
20
|
|