1
|
Chen CS, So EC, Wu SN. Modulating Hyperpolarization-Activated Cation Currents through Small Molecule Perturbations: Magnitude and Gating Control. Biomedicines 2023; 11:2177. [PMID: 37626674 PMCID: PMC10452073 DOI: 10.3390/biomedicines11082177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 07/10/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023] Open
Abstract
The hyperpolarization-activated cation current (Ih) exhibits a slowly activating time course of the current (Ih) when the cell membrane is hyperpolarized for an extended duration. It is involved in generating electrical activity in various excitable cells. Numerous structurally distinct compounds or herbal drugs have the potential to impact both the magnitude and gating kinetics of this current. Brivaracetam, a chemical analog of levetiracetam known to be a ligand for synaptic vesicle protein 2A, could directly suppress the Ih magnitude. Carisbamate, an anticonvulsant agent, not only inhibited the Ih amplitude but also reduced the strength of voltage-dependent hysteresis (Hys(V)) associated with Ih. Cilobradine, similar to ivabradine, inhibited the amplitude of Ih; however, it also suppressed the amplitude of delayed-rectifier K+ currents. Dexmedetomidine, an agonist of α2-adrenergic receptor, exerted a depressant action on Ih in a concentration-dependent fashion. Suppression of Ih amplitude was observed when GAL-021, a breathing control modulator, was present at a concentration exceeding 30 μM. Lutein, one of the few xanthophyll carotenoids, was able to suppress the Ih amplitude as well as to depress Hys(V)'s strength of Ih. Pirfenidone, a pyridine derivative known to be an anti-fibrotic agent, depressed the Ih magnitude in a concentration- and voltage-dependent fashion. Tramadol, a synthetic centrally active analgesic, was shown to reduce the Ih magnitude, independent of its interaction with opioid receptors. Various herbal drugs, including ent-kaurane-type diterpenoids from Croton tonkinensis, Ganoderma triterpenoids, honokiol, and pterostilbene, demonstrated efficacy in reducing the magnitude of Ih. Conversely, oxaliplatin, a platinum-based chemotherapeutic compound, was observed to effectively increase the Ih amplitude. Collectively, the regulatory effects of these compounds or herbal drugs on cellular function can be partly attributed to their perturbations on Ih.
Collapse
Affiliation(s)
- Cheng-Shih Chen
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan; (C.-S.C.); (E.C.S.)
| | - Edmund Cheung So
- Department of Anesthesia, An Nan Hospital, China Medical University, Tainan 70965, Taiwan; (C.-S.C.); (E.C.S.)
| | - Sheng-Nan Wu
- School of Medicine, National Sun Yat Sen University College of Medicine, Kaohsiung 804, Taiwan
- Department of Medical Education & Research, An Nan Hospital, China Medical University, Tainan 70965, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, Tainan 701, Taiwan
| |
Collapse
|
2
|
Liu C, Wang W, Shan Z, Zhang H, Yan Q. Dexmedetomidine as an adjuvant for patients undergoing breast cancer surgery: A meta-analysis. Medicine (Baltimore) 2020; 99:e23667. [PMID: 33327355 PMCID: PMC7738154 DOI: 10.1097/md.0000000000023667] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The goal of this study was to comprehensively evaluate the analgesic and antiemetic effects of adjuvant dexmedetomidine (DEX) for breast cancer surgery using a meta-analysis. METHODS Electronic databases were searched to collect the studies that performed randomized controlled trials. The effect size was estimated by odd ratio (OR) or standardized mean difference (SMD). Statistical analysis was performed using the STATA 13.0 software. RESULTS Twelve published studies involving 396 DEX treatment patients and 395 patients with control treatment were included. Pooled analysis showed that the use of DEX significantly prolonged the time to first request of analgesia (SMD = 1.67), decreased the postoperative requirement for tramadol (SMD = -0.65) and morphine (total: SMD = -2.23; patient-controlled analgesia: SMD = -1.45) as well as intraoperative requirement for fentanyl (SMD = -1.60), and lower the pain score at 1 (SMD = -0.30), 2 (SMD = -1.45), 4 (SMD = -2.36), 6 (SMD = -0.63), 8 (SMD = -2.47), 12 (SMD = -0.81), 24 (SMD = -1.78), 36 (SMD = -0.92), and 48 (SMD = -0.80) hours postoperatively compared with the control group. Furthermore, the risks to develop postoperative nausea/vomiting (PONV) (OR = 0.38) and vomiting (OR = 0.54) were significantly decreased in the DEX group compared with the control group. The pain relief at early time point (2, 6, 12, 24 hours postoperatively) and the decrease in the incidence of PONV were especially obvious for the general anesthesia subgroup (P < .05) relative to local anesthesia subgroup (P >.05). CONCLUSION DEX may be a favorable anesthetic adjuvant in breast cancer surgery, which could lower postoperative pain and the risk to develop PONV. DEX should be combined especially for the patients undergoing general anesthesia.
Collapse
Affiliation(s)
- Changjun Liu
- Operating Room, Yidu Central Hospital of Weifang
| | - Wei Wang
- Operating Room, Yidu Central Hospital of Weifang
| | | | - Huapeng Zhang
- Department of Anesthesiology, Yidu Central Hospital of Weifang
| | - Qiang Yan
- Intensive Care Unit, Weifang People's Hospital, Weifang, Shandong, China
| |
Collapse
|
3
|
Shahid M, Rinne JO, Scheinin M, Virta J, Marjamäki P, Solin O, Arponen E, Sallinen J, Kuokkanen K, Rouru J. Application of the PET ligand [ 11C]ORM-13070 to examine receptor occupancy by the α 2C-adrenoceptor antagonist ORM-12741: translational validation of target engagement in rat and human brain. EJNMMI Res 2020; 10:152. [PMID: 33296042 PMCID: PMC7726058 DOI: 10.1186/s13550-020-00741-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/25/2020] [Indexed: 12/31/2022] Open
Abstract
Background Availability of the α2C-adrenoceptor (α2C-AR) positron emission tomography (PET) tracer, [11C]ORM-13070, and the α2C-AR antagonist ORM-12741 allows probing of the roles of this G-protein coupled receptor subtype in brain function, both in healthy humans and in patients with various brain disorders. This translational study employed [11C]ORM-13070 autoradiography and PET to determine α2C-AR occupancy by ORM-12741 in rat and human brain, respectively. Results ORM-12741 has high affinity (Ki: 0.08 nM) and potent antagonist activity (Kb: 0.04 nM) as well as selectivity (Ki estimates for the human α2A-AR and α2B-AR were 8.3 nM and 0.8 nM, respectively) for the human α2C-AR subtype. [11C]ORM-13070 had highest uptake in the basal ganglia of rat and human brain. Pretreatment with ORM-12741 inhibited [11C]ORM-13070 binding in rat striatum in a time- and dose-dependent manner at 10 and 50 µg/kg (s.c.) with an EC50 estimate of 1.42 ng/mL in rat plasma, corresponding to protein-free drug concentration of 0.23 nM. In the living human brain, time- and dose-related α2C-AR occupancy was detected with EC50 estimates of 24 ng/mL and 31 ng/mL for the caudate nucleus and putamen, respectively, corresponding to protein-free concentrations in plasma of 0.07 nM and 0.1 nM. Modelling-based maximum α2C-AR occupancy estimates were 63% and 52% in the caudate nucleus and the putamen, respectively. Conclusions ORM-12741 is a selective α2C-AR antagonist which penetrates the rat and human brain to occupy α2C-ARs in a manner consistent with its receptor pharmacology. Trialregistrationnumberanddateofregistration: ClinicalTrial.cov NCT00829907. Registered 11 December 2008. https://clinicaltrials.gov/.
Collapse
Affiliation(s)
- Mohammed Shahid
- Orion Corporation, Orion Pharma, Research and Development, Tengströminkatu 8, 20380, Espoo, Finland.,Orion Corporation, Orion Pharma, Research and Development, Nottingham, UK
| | - Juha O Rinne
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.,Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland
| | - Mika Scheinin
- CRST, Turku, Finland.,Institute of Biomedicine, University of Turku, Turku, Finland.,Unit of Clinical Pharmacology, Turku University Hospital, Turku, Finland
| | - Jere Virta
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.,Division of Clinical Neurosciences, Turku University Hospital, Turku, Finland
| | - Päivi Marjamäki
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.,MediCity Research Laboratory, University of Turku, Turku, Finland
| | - Olof Solin
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.,Department of Chemistry, University of Turku, Turku, Finland.,Accelerator Laboratory, Åbo Akademi University, Turku, Finland
| | - Eveliina Arponen
- Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland
| | - Jukka Sallinen
- Orion Corporation, Orion Pharma, Research and Development, Tengströminkatu 8, 20380, Espoo, Finland
| | - Katja Kuokkanen
- Orion Corporation, Orion Pharma, Research and Development, Tengströminkatu 8, 20380, Espoo, Finland
| | - Juha Rouru
- Orion Corporation, Orion Pharma, Research and Development, Tengströminkatu 8, 20380, Espoo, Finland.
| |
Collapse
|
4
|
Lu TL, Lu TJ, Wu SN. Effectiveness in Block by Dexmedetomidine of Hyperpolarization-Activated Cation Current, Independent of Its Agonistic Effect on α 2-Adrenergic Receptors. Int J Mol Sci 2020; 21:E9110. [PMID: 33266068 PMCID: PMC7730867 DOI: 10.3390/ijms21239110] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 11/24/2020] [Accepted: 11/28/2020] [Indexed: 12/25/2022] Open
Abstract
Dexmedetomidine (DEX), a highly selective agonist of α2-adrenergic receptors, has been tailored for sedation without risk of respiratory depression. Our hypothesis is that DEX produces any direct perturbations on ionic currents (e.g., hyperpolarization-activated cation current, Ih). In this study, addition of DEX to pituitary GH3 cells caused a time- and concentration-dependent reduction in the amplitude of Ih with an IC50 value of 1.21 μM and a KD value of 1.97 μM. A hyperpolarizing shift in the activation curve of Ih by 10 mV was observed in the presence of DEX. The voltage-dependent hysteresis of Ih elicited by long-lasting triangular ramp pulse was also dose-dependently reduced during its presence. In continued presence of DEX (1 μM), further addition of OXAL (10 μM) or replacement with high K+ could reverse DEX-mediated inhibition of Ih, while subsequent addition of yohimbine (10 μM) did not attenuate the inhibitory effect on Ih amplitude. The addition of 3 μM DEX mildly suppressed the amplitude of erg-mediated K+ current. Under current-clamp potential recordings, the exposure to DEX could diminish the firing frequency of spontaneous action potentials. In pheochromocytoma PC12 cells, DEX was effective at suppressing Ih together with a slowing in activation time course of the current. Taken together, findings from this study strongly suggest that during cell exposure to DEX used at clinically relevant concentrations, the DEX-mediated block of Ih appears to be direct and would particularly be one of the ionic mechanisms underlying reduced membrane excitability in the in vivo endocrine or neuroendocrine cells.
Collapse
Affiliation(s)
- Te-Ling Lu
- School of Pharmacy, China Medical University, Taichung City 406040, Taiwan;
| | - Te-Jung Lu
- Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan City 71703, Taiwan;
| | - Sheng-Nan Wu
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung City 40402, Taiwan
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City 70101, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, No. 1, University Road, Tainan City 70101, Taiwan
| |
Collapse
|
5
|
Dexmedetomidine attenuates the induction and reverses the progress of 6-hydroxydopamine- induced parkinsonism; involvement of KATP channels, alpha 2 adrenoceptors and anti-inflammatory mechanisms. Toxicol Appl Pharmacol 2019; 382:114743. [DOI: 10.1016/j.taap.2019.114743] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 07/20/2019] [Accepted: 08/30/2019] [Indexed: 01/18/2023]
|
6
|
Selective adrenergic alpha2C receptor antagonist ameliorates acute phencyclidine-induced schizophrenia-like social interaction deficits in rats. Psychopharmacology (Berl) 2019; 236:1245-1253. [PMID: 30535904 PMCID: PMC6591184 DOI: 10.1007/s00213-018-5130-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 11/21/2018] [Indexed: 11/05/2022]
Abstract
RATIONALE Social withdrawal is a core feature of the negative symptoms of schizophrenia. Currently available pharmacotherapies have only limited efficacy towards the negative symptoms, i.e., there is a significant unmet medical need in the treatment of these symptoms. OBJECTIVE We wanted to confirm whether selective adrenergic α2C receptor (AR) antagonist therapy could ameliorate acute phencyclidine (PCP)-induced schizophrenia-like social interaction deficits in rats, and to compare the effects of an α2C AR antagonist to another putative therapeutic alternative, an α7 nicotinic acetylcholine receptor (nAChR) partial agonist, as well against three commonly used atypical antipsychotics. METHODS Here, we used acute PCP administration and modified a protocol for testing social interaction deficits in male Wistar rats and then used this model to compare the effects of an α2C AR antagonist (ORM-13070 0.3 and 1.0 mg/kg s.c.) with an α7 nAChR partial agonist (EVP-6124 0.3 mg/kg s.c.) and three atypical antipsychotics (clozapine 2.5 mg/kg i.p., risperidone 0.04 and 0.08 mg/kg s.c., olanzapine 0.125 and 0.5 mg/kg s.c.) on social interaction behavior. RESULTS Acute PCP (1.5 mg/kg s.c.) produced robust and reproducible deficits in social interaction behavior without affecting locomotor activity. The selective α2C AR antagonist significantly ameliorated PCP-induced social interaction deficits. In contrast, neither the partial α7 nAChR agonist nor any of the three atypical antipsychotics were able to reverse the behavioral deficits at the selected doses. CONCLUSION Our findings confirm that α2C AR antagonism is a potential mechanism for the treatment of the negative symptoms of schizophrenia.
Collapse
|
7
|
Sander CY, Hesse S. News and views on in-vivo imaging of neurotransmission using PET and MRI. THE QUARTERLY JOURNAL OF NUCLEAR MEDICINE AND MOLECULAR IMAGING : OFFICIAL PUBLICATION OF THE ITALIAN ASSOCIATION OF NUCLEAR MEDICINE (AIMN) [AND] THE INTERNATIONAL ASSOCIATION OF RADIOPHARMACOLOGY (IAR), [AND] SECTION OF THE SOCIETY OF... 2017; 61:414-428. [PMID: 28750497 PMCID: PMC5916779 DOI: 10.23736/s1824-4785.17.03019-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Molecular neuroimaging with PET is an integrated tool in psychiatry research and drug-development for as long as this modality has been available, in particular for studying neurotransmission and endogenous neurotransmitter release. Pharmacologic, behavioral and other types of challenges are currently applied to induce changes in neurochemical levels that can be inferred through their effects on changes in receptor binding and related outcome measures. Based on the availability of tracers that are sensitive for measuring neurotransmitter release these experiments have focused on the brain's dopamine system, while recent developments have extended those studies to other targets such as the serotonin or choline system. With the introduction of hybrid, truly simultaneous PET/MRI systems, in-vivo imaging of the dynamics of neuroreceptor signal transmission in the brain using PET and functional MRI (fMRI) has become possible. fMRI has the ability to provide information about the effects of receptor function that are complementary to the PET measurement. Dynamic acquisition of both PET and fMRI signals enables not only an in-vivo real-time assessment of neurotransmitter or drug binding to receptors but also dynamic receptor adaptations and receptor-specific neurotransmission. While fMRI temporal resolution is comparatively fast in relation to PET, the timescale of observable biological processes is highly dependent on the kinetics of radiotracers and study design. Overall, the combination of the specificity of PET radiotracers to neuroreceptors, fMRI signal as a functional readout and integrated study design promises to expand our understanding of the location, propagation and connections of brain activity in health and disease.
Collapse
Affiliation(s)
- Christin Y Sander
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA -
- Harvard Medical School, Boston, MA, USA -
| | - Swen Hesse
- Department of Nuclear Medicine, University of Leipzig, Leipzig, Germany
- Integrated Treatment and Research Center (IFB) Adiposity Diseases, Leipzig University Medical Center, Leipzig, Germany
| |
Collapse
|
8
|
Uys MM, Shahid M, Harvey BH. Therapeutic Potential of Selectively Targeting the α 2C-Adrenoceptor in Cognition, Depression, and Schizophrenia-New Developments and Future Perspective. Front Psychiatry 2017; 8:144. [PMID: 28855875 PMCID: PMC5558054 DOI: 10.3389/fpsyt.2017.00144] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 07/24/2017] [Indexed: 12/12/2022] Open
Abstract
α2A- and α2C-adrenoceptors (ARs) are the primary α2-AR subtypes involved in central nervous system (CNS) function. These receptors are implicated in the pathophysiology of psychiatric illness, particularly those associated with affective, psychotic, and cognitive symptoms. Indeed, non-selective α2-AR blockade is proposed to contribute toward antidepressant (e.g., mirtazapine) and atypical antipsychotic (e.g., clozapine) drug action. Both α2C- and α2A-AR share autoreceptor functions to exert negative feedback control on noradrenaline (NA) release, with α2C-AR heteroreceptors regulating non-noradrenergic transmission (e.g., serotonin, dopamine). While the α2A-AR is widely distributed throughout the CNS, α2C-AR expression is more restricted, suggesting the possibility of significant differences in how these two receptor subtypes modulate regional neurotransmission. However, the α2C-AR plays a more prominent role during states of low endogenous NA activity, while the α2A-AR is relatively more engaged during states of high noradrenergic tone. Although augmentation of conventional antidepressant and antipsychotic therapy with non-selective α2-AR antagonists may improve therapeutic outcome, animal studies report distinct yet often opposing roles for the α2A- and α2C-ARs on behavioral markers of mood and cognition, implying that non-selective α2-AR antagonism may compromise therapeutic utility both in terms of efficacy and side-effect liability. Recently, several highly selective α2C-AR antagonists have been identified that have allowed deeper investigation into the function and utility of the α2C-AR. ORM-13070 is a useful positron emission tomography ligand, ORM-10921 has demonstrated antipsychotic, antidepressant, and pro-cognitive actions in animals, while ORM-12741 is in clinical development for the treatment of cognitive dysfunction and neuropsychiatric symptoms in Alzheimer's disease. This review will emphasize the importance and relevance of the α2C-AR as a neuropsychiatric drug target in major depression, schizophrenia, and associated cognitive deficits. In addition, we will present new prospects and future directions of investigation.
Collapse
Affiliation(s)
- Madeleine Monique Uys
- Division of Pharmacology, Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| | | | - Brian Herbert Harvey
- Division of Pharmacology, Centre of Excellence for Pharmaceutical Sciences, North-West University, Potchefstroom, South Africa
| |
Collapse
|
9
|
|