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Kobayashi Y, Watanabe N, Hiura R, Kubota M, Furuta K, Sugimoto K, Murota K, Nakamura E, Matsuura T, Kai K, Inui T, Kitakaze T, Harada N, Yamaji R. Transport Form and Pathway from the Intestine to the Peripheral Tissues and the Intestinal Absorption and Metabolism Properties of Oleamide. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:15499-15508. [PMID: 36458736 DOI: 10.1021/acs.jafc.2c06791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
This study aimed to obtain information on the transport form and pathway from the intestine to the peripheral tissues and on the intestinal absorption and metabolism properties of oleamide (cis-9-octadecenamide). Oleamide was primarily transported via the portal vein. Density gradient centrifugation indicated that plasma oleamide was enriched in the fractions containing albumin in the portal and peripheral blood. Oleamide formed a complex with albumin in an endothermic reaction (apparent Kd = 4.4 μM). The CD36 inhibitor inhibited the oleamide uptake into the intestinal epithelial Caco-2 cells, and oleamide decreased the cell surface CD36 level. The fatty acid amide hydrolase (FAAH) inhibitor increased the transepithelial transport of oleamide across Caco-2 cells and the plasma oleamide concentration in mice intragastrically administered with oleamide. These results indicate that oleamide is transported primarily via the portal vein as a complex with albumin. Furthermore, we suggest that oleamide is taken up via CD36 in the small intestine and degraded intracellularly by FAAH.
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Affiliation(s)
- Yasuyuki Kobayashi
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
| | - Natsumi Watanabe
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
| | - Reina Hiura
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
| | - Mai Kubota
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
| | - Kousuke Furuta
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
| | - Keiichiro Sugimoto
- Research and Development Center, Nagaoka Co., Ltd., Ibaraki, Osaka 5670005, Japan
- Center for Research and Development of Bioresources, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
| | - Kaeko Murota
- Department of Life Sciences, Faculty of Life and Environmental Sciences, Shimane University, Matsue, Shimane 6908504, Japan
| | - Eri Nakamura
- Department of Innovative Food Sciences, School of Food Sciences and Nutrition, Mukogawa Women's University, Nishinomiya, Hyogo 6638558, Japan
| | - Toshiki Matsuura
- Department of Innovative Food Sciences, School of Food Sciences and Nutrition, Mukogawa Women's University, Nishinomiya, Hyogo 6638558, Japan
| | - Kenji Kai
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
| | - Takashi Inui
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
| | - Tomoya Kitakaze
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
| | - Naoki Harada
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
| | - Ryoichi Yamaji
- Division of Applied Life Sciences, Graduate School of Life and Environmental Sciences, Osaka Prefecture University, Sakai, Osaka 5998531, Japan
- Department of Applied Biological Chemistry, Graduate School of Agriculture, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
- Center for Research and Development of Bioresources, Osaka Metropolitan University, Sakai, Osaka 5998531, Japan
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Yerlikaya S, Djamgoz MB. Oleamide, a Sleep-Inducing Compound: Effects on Ion Channels and Cancer. Bioelectricity 2022. [DOI: 10.1089/bioe.2022.0010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Serife Yerlikaya
- Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
| | - Mustafa B.A. Djamgoz
- Department of Life Sciences, Imperial College London, London, United Kingdom
- Biotechnology Research Center, Cyprus International University, Haspolat, Nicosia, TRNC, Mersin 10, Turkey
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Characterization of Convergent Suppression by UCL-2077 (3-(Triphenylmethylaminomethyl)pyridine), Known to Inhibit Slow Afterhyperpolarization, of erg-Mediated Potassium Currents and Intermediate-Conductance Calcium-Activated Potassium Channels. Int J Mol Sci 2020; 21:ijms21041441. [PMID: 32093314 PMCID: PMC7073080 DOI: 10.3390/ijms21041441] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 01/06/2023] Open
Abstract
UCL-2077 (triphenylmethylaminomethyl)pyridine) was previously reported to suppress slow afterhyperpolarization in neurons. However, the information with respect to the effects of UCL-2077 on ionic currents is quite scarce. The addition of UCL-2077 decreased the amplitude of erg-mediated K+ current (IK(erg)) together with an increased deactivation rate of the current in pituitary GH3 cells. The IC50 and KD values of UCL-2077-induced inhibition of IK(erg) were 4.7 and 5.1 μM, respectively. UCL-2077 (10 μM) distinctly shifted the midpoint in the activation curve of IK(erg) to less hyperpolarizing potentials by 17 mV. Its presence decreased the degree of voltage hysteresis for IK(erg) elicitation by long-lasting triangular ramp pulse. It also diminished the probability of the opening of intermediate-conductance Ca2+-activated K+ channels. In cell-attached current recordings, UCL-2077 raised the frequency of action currents. When KCNH2 mRNA was knocked down, a UCL-2077-mediated increase in AC firing was attenuated. Collectively, the actions elaborated herein conceivably contribute to the perturbating effects of this compound on electrical behaviors of excitable cells.
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Chang WT, Lo YC, Gao ZH, Wu SN. Evidence for the Capability of Roxadustat (FG-4592), an Oral HIF Prolyl-Hydroxylase Inhibitor, to Perturb Membrane Ionic Currents: An Unidentified yet Important Action. Int J Mol Sci 2019; 20:ijms20236027. [PMID: 31795416 PMCID: PMC6928729 DOI: 10.3390/ijms20236027] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/18/2019] [Accepted: 11/25/2019] [Indexed: 12/13/2022] Open
Abstract
Roxadustat (FG-4592), an analog of 2-oxoglutarate, is an orally-administered, heterocyclic small molecule known to be an inhibitor of hypoxia inducible factor (HIF) prolyl hydroxylase. However, none of the studies have thus far thoroughly investigated its possible perturbations on membrane ion currents in endocrine or heart cells. In our studies, the whole-cell current recordings of the patch-clamp technique showed that the presence of roxadustat effectively and differentially suppressed the peak and late components of IK(DR) amplitude in response to membrane depolarization in pituitary tumor (GH3) cells with an IC50 value of 5.71 and 1.32 μM, respectively. The current inactivation of IK(DR) elicited by 10-sec membrane depolarization became raised in the presence of roxadustatt. When cells were exposed to either CoCl2 or deferoxamine (DFO), the IK(DR) elicited by membrane depolarization was not modified; however, nonactin, a K+-selective ionophore, in continued presence of roxadustat, attenuated roxadustat-mediated inhibition of the amplitude. The steady-state inactivation of IK(DR) could be constructed in the presence of roxadustat. Recovery of IK(DR) block by roxadustat (3 and 10 μM) could be fitted by a single exponential with 382 and 523 msec, respectively. The roxadustat addition slightly suppressed erg-mediated K+ or hyperpolarization-activated cation currents. This drug also decreased the peak amplitude of voltage-gated Na+ current with a slowing in inactivation rate of the current. Likewise, in H9c2 heart-derived cells, the addition of roxadustat suppressed IK(DR) amplitude in combination with the shortening in inactivation time course of the current. In high glucose-treated H9c2 cells, roxadustat-mediated inhibition of IK(DR) remained unchanged. Collectively, despite its suppression of HIF prolyl hydroxylase, inhibitory actions of roxadustat on different types of ionic currents possibly in a non-genomic fashion might provide another yet unidentified mechanism through which cellular functions are seriously perturbed, if similar findings occur in vivo.
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Affiliation(s)
- Wei-Ting Chang
- Division of Cardiovascular Medicine, Chi-Mei Medical Center, Tainan 71004 Taiwan;
- Department of Biotechnology, Southern Taiwan University of Science and Technology, Tainan 71004, Taiwan
- Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan
| | - Yi-Ching Lo
- Department of Pharmacology, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Zi-Han Gao
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan;
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan;
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Basic Medical Sciences, China Medical University Hospital, Taichung 40402, Taiwan
- Correspondence: ; Tel.: +886-6-2353535-5334/886-6-2362780
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Castillo-Peinado L, López-Bascón M, Mena-Bravo A, Luque de Castro M, Priego-Capote F. Determination of primary fatty acid amides in different biological fluids by LC–MS/MS in MRM mode with synthetic deuterated standards: Influence of biofluid matrix on sample preparation. Talanta 2019; 193:29-36. [DOI: 10.1016/j.talanta.2018.09.088] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/21/2018] [Accepted: 09/24/2018] [Indexed: 12/18/2022]
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Elinder F, Liin SI. Actions and Mechanisms of Polyunsaturated Fatty Acids on Voltage-Gated Ion Channels. Front Physiol 2017; 8:43. [PMID: 28220076 PMCID: PMC5292575 DOI: 10.3389/fphys.2017.00043] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 01/16/2017] [Indexed: 01/29/2023] Open
Abstract
Polyunsaturated fatty acids (PUFAs) act on most ion channels, thereby having significant physiological and pharmacological effects. In this review we summarize data from numerous PUFAs on voltage-gated ion channels containing one or several voltage-sensor domains, such as voltage-gated sodium (NaV), potassium (KV), calcium (CaV), and proton (HV) channels, as well as calcium-activated potassium (KCa), and transient receptor potential (TRP) channels. Some effects of fatty acids appear to be channel specific, whereas others seem to be more general. Common features for the fatty acids to act on the ion channels are at least two double bonds in cis geometry and a charged carboxyl group. In total we identify and label five different sites for the PUFAs. PUFA site 1: The intracellular cavity. Binding of PUFA reduces the current, sometimes as a time-dependent block, inducing an apparent inactivation. PUFA site 2: The extracellular entrance to the pore. Binding leads to a block of the channel. PUFA site 3: The intracellular gate. Binding to this site can bend the gate open and increase the current. PUFA site 4: The interface between the extracellular leaflet of the lipid bilayer and the voltage-sensor domain. Binding to this site leads to an opening of the channel via an electrostatic attraction between the negatively charged PUFA and the positively charged voltage sensor. PUFA site 5: The interface between the extracellular leaflet of the lipid bilayer and the pore domain. Binding to this site affects slow inactivation. This mapping of functional PUFA sites can form the basis for physiological and pharmacological modifications of voltage-gated ion channels.
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Affiliation(s)
- Fredrik Elinder
- Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden
| | - Sara I Liin
- Department of Clinical and Experimental Medicine, Linköping University Linköping, Sweden
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Hsu HT, Tseng YT, Lo YC, Wu SN. Ability of naringenin, a bioflavonoid, to activate M-type potassium current in motor neuron-like cells and to increase BKCa-channel activity in HEK293T cells transfected with α-hSlo subunit. BMC Neurosci 2014; 15:135. [PMID: 25539574 PMCID: PMC4288500 DOI: 10.1186/s12868-014-0135-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 12/11/2014] [Indexed: 12/17/2022] Open
Abstract
Background Naringenin (NGEN) is a citrus bioflavonoid known to have beneficial health properties; however, the ionic mechanism of its actions remains largely unclear. In this study, we attempted to evaluate the possible effects of NGEN on K+ currents in NSC-34 neuronal cells and in HEK293T cells expressing α-hSlo. Results NGEN increased M-type K+ current (IK(M)) in a concentration-dependent manner with an EC50 value of 9.8 μM in NSC-34 cells. NGEN shifted the activation curve of IK(M) conductance to the more negative potentials. In cell-attached recordings, NGEN or flupirtine enhanced the activity of M-type K+ (KM) channels with no changes in single-channel amplitude. NGEN (10 μM) had minimal effect on erg-mediated K+ currents. Under cell-attached voltage-clamp recordings, NGEN decreased the frequency of spontaneous action currents and further application of linopirdine can reverse NGEN-induced inhibition of firing. In HEK293T cells expressing α-hSlo, this compound increased the amplitude of Ca2+-activated K+ current (IK(Ca)). Under inside-out recordings, NGEN applied to the intracellular side of the detached patch enhanced the activity of large-conductance Ca2+-activated K+ (BKCa) channels. Moreover, from the study of a modeled neuron, burst firing of simulated action potentials (APs) was reduced in the presence of the increased conductances of both KM and KCa channels. Fast-slow analysis of AP bursting from this model also revealed that as the conductances of both KM and BKCa channels were increased by two-fold, the voltage nullcline was shifted in an upward direction accompanied by the compression of burst trajectory. Conclusions The present results demonstrate that activation of both KM and BKCa channels caused by NGEN might combine to influence neuronal activity if similar channels were functionally co-expressed in central neurons in vivo.
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Affiliation(s)
- Hung-Te Hsu
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Department of Anesthesia, Kaohsiung Medical University Hospital, Kaohsiung City, 80708, Taiwan.
| | - Yu-Ting Tseng
- Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Graduate Institute of Natural Products, School of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
| | - Yi-Ching Lo
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Department of Pharmacology, School of Medicine, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan. .,Graduate Institute of Natural Products, School of Pharmacy, Kaohsiung Medical University, Kaohsiung, 80708, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan City, 70101, Taiwan. .,Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan City, 70101, Taiwan.
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Bertin MJ, Moeller P, Guillette LJ, Chapman RW. Using machine learning tools to model complex toxic interactions with limited sampling regimes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:2728-2736. [PMID: 23402624 DOI: 10.1021/es3033549] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A major impediment to understanding the impact of environmental stress, including toxins and other pollutants, on organisms, is that organisms are rarely challenged by one or a few stressors in natural systems. Thus, linking laboratory experiments that are limited by practical considerations to a few stressors and a few levels of these stressors to real world conditions is constrained. In addition, while the existence of complex interactions among stressors can be identified by current statistical methods, these methods do not provide a means to construct mathematical models of these interactions. In this paper, we offer a two-step process by which complex interactions of stressors on biological systems can be modeled in an experimental design that is within the limits of practicality. We begin with the notion that environment conditions circumscribe an n-dimensional hyperspace within which biological processes or end points are embedded. We then randomly sample this hyperspace to establish experimental conditions that span the range of the relevant parameters and conduct the experiment(s) based upon these selected conditions. Models of the complex interactions of the parameters are then extracted using machine learning tools, specifically artificial neural networks. This approach can rapidly generate highly accurate models of biological responses to complex interactions among environmentally relevant toxins, identify critical subspaces where nonlinear responses exist, and provide an expedient means of designing traditional experiments to test the impact of complex mixtures on biological responses. Further, this can be accomplished with an astonishingly small sample size.
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Affiliation(s)
- Matthew J Bertin
- MUSC/Marine Biomedicine & Environmental Sciences, Hollings Marine Laboratory, 331 Fort Johnson Road, Charleston, South Carolina 29412, USA
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Wu SN, Yang WH, Yeh CC, Huang HC. The inhibition by di(2-ethylhexyl)-phthalate of erg-mediated K⁺ current in pituitary tumor (GH₃) cells. Arch Toxicol 2012; 86:713-23. [PMID: 22314968 DOI: 10.1007/s00204-012-0805-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2011] [Accepted: 01/11/2012] [Indexed: 12/24/2022]
Abstract
DEHP (bis(2-ethylhexyl)-phthalate) known to be an endocrine-disrupting chemical is a widely used phthalate. Little information regarding the effects of phthalate esters on ion currents is available. In this study, the effects of DEHP and other phthalate esters (DBEP: di(2-butoxyethyl)-phthalate and DMGP: di(2-methylglycol)-phthalate) on ion currents were investigated in pituitary GH₃ cells. Hyperpolarization-elicited K⁺ currents in GH3 cells bathed in high-K⁺, Ca²⁺-free solution were examined to evaluate the effects of DEHP, DBEP, and DMGP on the ether-a`-go-go-related-gene (erg) K⁺ current (IK(erg)). Addition of DEHP to GH₃ cells suppressed the amplitude of IK(erg) in a concentration-dependent manner with an IC₅₀ value of 16.3 μM. With a two-pulse protocol, addition of DEHP shifted the activation curve of IK(erg) to a depolarized potential by approximately 10 mV with no change in the rate of IK(erg) deactivation. This compound did not have any effects on delayed rectifier K⁺ current in GH₃ cells, while 4-aminopyridine-3-methanol (100 μM) suppressed this current significantly. DBEP (30 μM) had little or no effect on IK(erg), while DMGP (30 μM) slightly reduced it. In inside-out configuration, DEHP (30 μM) applied to the bath slightly reduced the activity of large-conductance Ca²⁺-activated K⁺ channels. DEHP (30 μM) increased the frequency of spontaneous action potentials (APs); however, this compound at the same concentration had no effect on AP firing in KCNH2 siRNA-transfected GH₃ cells. The effects described herein can contribute to their actions on functional activity of endocrine or neuroendocrine cells if similar results are found in vivo.
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Affiliation(s)
- Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, No. 1 University Road, Tainan City 70101, Taiwan.
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The actions of mdivi-1, an inhibitor of mitochondrial fission, on rapidly activating delayed-rectifier K+ current and membrane potential in HL-1 murine atrial cardiomyocytes. Eur J Pharmacol 2012; 683:1-9. [DOI: 10.1016/j.ejphar.2012.02.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 02/01/2012] [Accepted: 02/08/2012] [Indexed: 01/03/2023]
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Liu YC, Wu PC, Shieh DB, Wu SN. The effects of magnetite (Fe₃O₄) nanoparticles on electroporation-induced inward currents in pituitary tumor (GH₃) cells and in RAW 264.7 macrophages. Int J Nanomedicine 2012; 7:1687-96. [PMID: 22615532 PMCID: PMC3357052 DOI: 10.2147/ijn.s28798] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aims Fe3O4 nanoparticles (NPs) have been known to provide a distinct image contrast effect for magnetic resonance imaging owing to their super paramagnetic properties on local magnetic fields. However, the possible effects of these NPs on membrane ion currents that concurrently induce local magnetic field perturbation remain unclear. Methods We evaluated whether amine surface-modified Fe3O4 NPs have any effect on ion currents in pituitary tumor (GH3) cells via voltage clamp methods. Results The addition of Fe3O4 NPs decreases the amplitude of membrane electroporation-induced currents (IMEP) with a half-maximal inhibitory concentration at 45 μg/mL. Fe3O4 NPs at a concentration of 3 mg/mL produced a biphasic response in the amplitude of IMEP, ie, an initial decrease followed by a sustained increase. A similar effect was also noted in RAW 264.7 macrophages. Conclusion The modulation of magnetic electroporation-induced currents by Fe3O4 NPs constitutes an important approach for cell tracking under various imaging modalities or facilitated drug delivery.
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Affiliation(s)
- Yen-Chin Liu
- Department of Anesthesiology, National Cheng Kung University Hospital, College of Medicine, Tainan, Taiwan
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Farrell EK, Chen Y, Barazanji M, Jeffries KA, Cameroamortegui F, Merkler DJ. Primary fatty acid amide metabolism: conversion of fatty acids and an ethanolamine in N18TG2 and SCP cells. J Lipid Res 2011; 53:247-56. [PMID: 22095832 DOI: 10.1194/jlr.m018606] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Primary fatty acid amides (PFAM) are important signaling molecules in the mammalian nervous system, binding to many drug receptors and demonstrating control over sleep, locomotion, angiogenesis, and many other processes. Oleamide is the best-studied of the primary fatty acid amides, whereas the other known PFAMs are significantly less studied. Herein, quantitative assays were used to examine the endogenous amounts of a panel of PFAMs, as well as the amounts produced after incubation of mouse neuroblastoma N(18)TG(2) and sheep choroid plexus (SCP) cells with the corresponding fatty acids or N-tridecanoylethanolamine. Although five endogenous primary amides were discovered in the N(18)TG(2) and SCP cells, a different pattern of relative amounts were found between the two cell lines. Higher amounts of primary amides were found in SCP cells, and the conversion of N-tridecanoylethanolamine to tridecanamide was observed in the two cell lines. The data reported here show that the N(18)TG(2) and SCP cells are excellent model systems for the study of PFAM metabolism. Furthermore, the data support a role for the N-acylethanolamines as precursors for the PFAMs and provide valuable new kinetic results useful in modeling the metabolic flux through the pathways for PFAM biosynthesis and degradation.
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Affiliation(s)
- Emma K Farrell
- Department of Chemistry, University of South Florida, Tampa, FL 33620-5250, USA
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Huang MH, Shen AY, Wang TS, Wu HM, Kang YF, Chen CT, Hsu TI, Chen BS, Wu SN. Inhibitory action of methadone and its metabolites on erg-mediated K+ current in GH₃ pituitary tumor cells. Toxicology 2010; 280:1-9. [PMID: 21094671 DOI: 10.1016/j.tox.2010.10.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Revised: 10/20/2010] [Accepted: 10/21/2010] [Indexed: 01/05/2023]
Abstract
Methadone (Mtd) is a widely used opioid drug associated with the side effect of hyperprolactinemia. The mechanism of how Mtd induces prolactin secretion remains unclear. The effects of Mtd and its two main metabolites (EDDP: (±)-2-ethyl-1,5-dimethyl-3,3-diphenylpyrrolinium percholarate and EMDP: 2-ethyl-5-methyl-3,3-dipnehyl-1-pyrroline) on ion currents were investigated in GH₃ pituitary tumor cells. Hyperpolarization-elicited K+ currents in GH₃ cells bathed in a high-K(+), Ca(2+)-free solution were studied to evaluate the effects of Mtd and other related compounds on the ether-à-go-go-related-gene (erg) K(+) current (I(K(erg))). Mtd suppressed the amplitude of I(K(erg)) in a concentration-dependent manner with an IC(50) value of 10.4 μM. With the aid of a minimal binding scheme, the inhibitory action of Mtd on I(K(erg)) was estimated with a dissociation constant of 8.2 μM. Mtd tended to increase the rate of I(K(erg)) deactivation in a voltage-dependent fashion. EDDP (10 μM) had no effect on I(K(erg)), while EMDP (10μM) slightly suppressed it. In GH₃ cells incubated with naloxone (30 μM), the Mtd-induced inhibition of I(K(erg)) remained unaltered. Under cell-attached voltage-clamp recordings, Mtd increased the frequency of spontaneous action currents with no change in current amplitude. Similarly, Mtd can suppress I(K(erg)) in differentiated NG108-15 cells; dynorphin A(1-13) did not reverse Mtd-induced inhibition of I(K(erg)). This study shows that Mtd has a depressant effect on I(K(erg)), and suggests its ability to affect membrane excitability and prolactin secretion. The cyclization of Mtd, in which EDDP and EMDP are formed, tends to be critical in removal of the Mtd binding to erg K+ channel.
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Affiliation(s)
- Mei-Han Huang
- College of Medical and Health Sciences, Fooyin University, Ta-Liao, Kaohsiung County, Taiwan
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Chen BS, Lo YC, Peng H, Hsu TI, Wu SN. Effects of ranolazine, a novel anti-anginal drug, on ion currents and membrane potential in pituitary tumor GH(3) cells and NG108-15 neuronal cells. J Pharmacol Sci 2009; 110:295-305. [PMID: 19609066 DOI: 10.1254/jphs.09018fp] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Ranolazine, a piperazine derivative, is currently approved for the treatment of chronic angina. However, its ionic mechanisms in other types of cells remain unclear, although it is thought to be a selective blocker of late Na(+) current. This study was conducted to evaluate the possible effects of ranolazine on Na(+) current (I(Na)), L-type Ca(2+) current (I(Ca,L)), inwardly rectifying K(+) current (I(K(IR))), delayed-rectifier K(+) current (I(K(DR))), and Ca(2+)-activated K(+) current (I(K(Ca))) in pituitary tumor (GH(3)) cells. Ranolazine depressed the transient and late components of I(Na) with different potencies. This drug exerted an inhibitory effect on I(K(IR)) with an IC(50) value of 0.92 microM, while it slightly inhibited I(K(DR)) and I(K(Ca)). It shifted the steady-state activation curve of I(K(IR)) to more positive potentials with no change in the gating charge of the channel. Ranolazine (30 microM) also reduced the activity of large-conductance Ca(2+)-activated K(+) channels in HEK293T cells expressing alpha-hSlo. Under current-clamp conditions, low concentrations (e.g., 1 microM) of ranolazine increased the firing of action potentials, while at high concentrations (>or=10 microM), it diminished the firing discharge. The exposure to ranolazine also suppressed I(Na) and I(K(IR)) effectively in NG108-15 neuronal cells. Our study provides evidence that ranolazine could block multiple ion currents such as I(Na) and I(K(IR)) and suggests that these actions may contribute to some of the functional activities of neurons and endocrine or neuroendocrine cells in vivo.
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Affiliation(s)
- Bing-Shuo Chen
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Taiwan
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15
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Wu SN, Peng H, Chen BS, Wang YJ, Wu PY, Lin MW. Potent activation of large-conductance Ca2+-activated K+ channels by the diphenylurea 1,3-bis-[2-hydroxy-5-(trifluoromethyl)phenyl]urea (NS1643) in pituitary tumor (GH3) cells. Mol Pharmacol 2008; 74:1696-704. [PMID: 18809671 DOI: 10.1124/mol.108.049106] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
1,3-Bis-[2-hydroxy-5-(trifluoromethyl)phenyl]urea (NS1643) is reported to be an activator of human ether-à-go-go-related gene current. However, it remains unknown whether it has any effects on other types of ion channels. The effects of NS1643 on ion currents and membrane potential were investigated in this study. NS1643 stimulated Ca(2+)-activated K(+) current [I(K(Ca))] in a concentration-dependent manner with an EC(50) value of 1.8 microM in pituitary tumor (GH(3)) cells. In inside-out recordings, this compound applied to the intracellular side of the detached channels stimulated large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels with no change in single-channel conductance. It shifted the activation curve of BK(Ca) channels to less depolarized voltages without altering the gating charge of the channels. NS1643-stimulated channel activity depended on intracellular Ca(2+), and mean closed time during exposure to NS1643 was reduced. NS1643 (3 microM) had little or no effect on peak amplitude of ether-à-go-go-related gene-mediated K(+) current evoked by membrane hyperpolarization, although it increased the amplitude of late-sustained components of K(+) inward current, which was suppressed by paxilline but not by azimilide. NS1643 (3 microM) had no effect on L-type Ca(2+) current. This compound reduced repetitive firing of action potentials, and further application of paxilline attenuated its decrease in firing rate. In addition, NS1643 enhanced BK(Ca)-channel activity in human embryonic kidney 293T cells expressing alpha-hSlo. In summary, we clearly show that NS1643 interacts directly with the BK(Ca) channel to increase the amplitude of I(K(Ca)) in pituitary tumor (GH(3)) cells. The alpha-subunit of the channel may be a target for the action of this small compound.
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Affiliation(s)
- Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan.
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Farrell EK, Merkler DJ. Biosynthesis, degradation and pharmacological importance of the fatty acid amides. Drug Discov Today 2008; 13:558-68. [PMID: 18598910 DOI: 10.1016/j.drudis.2008.02.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2007] [Revised: 01/29/2008] [Accepted: 02/18/2008] [Indexed: 01/08/2023]
Abstract
The identification of two biologically active fatty acid amides, N-arachidonoylethanolamine (anandamide) and oleamide, has generated a great deal of excitement and stimulated considerable research. However, anandamide and oleamide are merely the best-known and best-understood members of a much larger family of biologically occurring fatty acid amides. In this review, we will outline which fatty acid amides have been isolated from mammalian sources, detail what is known about how these molecules are made and degraded in vivo, and highlight their potential for the development of novel therapeutics.
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Affiliation(s)
- Emma K Farrell
- Department of Chemistry, University of South Florida, Tampa, FL 33620, USA
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Wu SN, Lin MW, Wang YJ. Stimulatory actions of di-8-butyl-amino-naphthyl-ethylene-pyridinium-propyl-sulfonate (di-8-ANEPPS), voltage-sensitive dye, on the BKCa channel in pituitary tumor (GH3) cells. Pflugers Arch 2007; 455:687-99. [PMID: 17701422 DOI: 10.1007/s00424-007-0329-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Revised: 07/16/2007] [Accepted: 07/24/2007] [Indexed: 11/29/2022]
Abstract
Di-8-ANEPPS (4-{2-[6-(dibutylamino)-2-naphthalenyl]-ethenyl}-1-(3-sulfopropyl)pyridinium inner salt) has been used as a fast-response voltage-sensitive styrylpyridinium probe. However, little is known regarding the mechanism of di-8-ANEPPS actions on ion currents. In this study, the effects of this dye on ion currents were investigated in pituitary GH(3) cells. In whole-cell configuration, di-8-ANEPPS (10 microM) reversibly increased the amplitude of Ca(2+)-activated K(+) current. In inside-out configuration, di-8-ANEPPS (10 microM) applied to the intracellular surface of the membrane caused no change in single-channel conductance; however, it did enhance the activity of large-conductance Ca(2+)-activated K(+) (BK(Ca)) channels with an EC(50) value of 7.5 microM. This compound caused a left shift in the activation curve of BK(Ca) channels with no change in the gating charge of these channels. A decrease in mean closed time of the channels was seen in the presence of this dye. In the cell-attached mode, di-8-ANEPPS applied on the extracellular side of the membrane also activated BK(Ca) channels. However, neither voltage-gated K(+) nor ether-à-go-go-related gene (erg)-mediated K(+) currents in GH(3) cells were affected by di-8-APPNES. Under current-clamp configuration, di-8-ANEPPS (10 microM) decreased the firing of action potentials in GH(3) cells. In pancreatic betaTC-6 cells, di-8-APPNES (10 microM) also increased BK(Ca)-channel activity. Taken together, this study suggests that during the exposure to di-8-ANEPPS, the stimulatory effects on BK(Ca) channels could be one of potential mechanisms through which it may affect cell excitability.
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Affiliation(s)
- Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, No. 1, University Road, Tainan 70101 Taiwan, Republic of China.
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18
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Irmisch G, Schläfke D, Gierow W, Herpertz S, Richter J. Fatty acids and sleep in depressed inpatients. Prostaglandins Leukot Essent Fatty Acids 2007; 76:1-7. [PMID: 17123808 DOI: 10.1016/j.plefa.2006.09.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2006] [Revised: 08/15/2006] [Accepted: 09/14/2006] [Indexed: 10/23/2022]
Abstract
Sleep disturbances belong to the most frequent symptoms of depression. Low concentrations of n-3-fatty acids might represent one determinant within that process. Therefore, the aim of the study was to examine the relationships between serum fatty acid concentrations and severity of sleep disturbances in depressives. Serum fatty acids were measured gaschromatographically in 118 depressive inpatients (51 males; 67 females; age 45.4+/-12.0 years), divided into subgroups according to three degrees of sleep disturbances (BDI-item). At admission and discharge, we found significant negative correlations between the degree of sleep disturbances and fatty acid concentrations (myristic, palmitic, palmitoleic, oleic, linoleic, eicosadienoic and docosahexaenoic acid). At both assessments palmitoleic and eicosadienoic acids had the strongest connections with sleep performance. Palmitoleic and oleic acid seem to be especially important for sleep disorders, may be due to their function as precursors of the sleep inducing oleamide. Linoleic and eicosadienoic acid could be helpful for maintaining sleep because they are precursors of the sleep mediator PGD2. In contrast to our hypothesis, there is not only a significant lack of n-3 fatty acids but also of special monoenoic and n-6 fatty acids in sleep-disturbed depressives.
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Affiliation(s)
- G Irmisch
- Department of Psychiatry and Psychotherapy, Rostock University, Gehlsheimer Strasse 20, D-18147 Rostock, Germany.
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19
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Sultana T, Johnson ME. Sample preparation and gas chromatography of primary fatty acid amides. J Chromatogr A 2005; 1101:278-85. [PMID: 16266715 DOI: 10.1016/j.chroma.2005.10.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 10/07/2005] [Accepted: 10/11/2005] [Indexed: 11/28/2022]
Abstract
A method for the isolation of bio-active primary fatty acid amides (PFAM's) from total lipid extract by solid-phase extraction (SPE) was developed and validated. The lowest mass of amide to be loaded and recovered by this method was detected as 0.5 microg using 500 mg of normal phase adsorbent. The isolated PFAM's were separated and quantified by GC/MS and percent recoveries were calculated. An HP-5MS column was able to provide base line separation between the saturated and unsaturated PFAM's whereas clear resolution between geometric and positional isomers having the same number of carbons was obtained using a BPX70 column. The separated amides were all 18 carbon analogs of cis-9-octadecenoamide (oleamide). Detection limits in the single ion monitoring mode were found to be on the order of 10 pg in a 1 microl injection. Solid phase extraction of amides from total lipid extract before GC/MS analysis provides clean detection and interference free analysis.
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Affiliation(s)
- Tamanna Sultana
- Department of Chemistry and Biochemistry, Duquesne University, Pittsburgh, PA 15282, USA
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Sauviat MP, Bouvet S, Godeau G, Pages N. Electrical activity alterations induced by chronic absorption of lindane (γ-hexachlorocyclohexane) trace concentrations in adult rat heart. Can J Physiol Pharmacol 2005; 83:243-51. [PMID: 15870838 DOI: 10.1139/y04-132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The heart of adult rat offspring, born to mothers treated with trace concentrations of lindane (0.5 to 2 ppb) through a beverage and to mothers chronically treated with lindane (CL-T) with the same trace concentration, also through a beverage, during lactation and growth has a round shape and accumulates lindane. The left ventricle (LV) presents a hypertrophied area, atrophied papillary muscles, and unorganized collagen bundles and layers. These observations led us to study the electrical activity of their left ventricle papillary muscles (LVPM) by recording action potential using intracellular microelectrodes. CL-T shortened LVPM action potential duration (APD): 1 ppb shortened the plateau; 2 ppb shortened the plateau and the slow repolarizing phase. In CL-T (2 ppb) and untreated groups, low temperature (22 °C) decreased the resting potential and prolonged APD. TEA (tetraethylammonium; 1-2 mmol/L) partially lengthened CL-T (2 ppb lindane) APD. Quinidine (0.2 mmol/L) and E-4031 (10 nmol/L) prolonged CL-T APD, suggesting that the rapid delayed outward K+ current (IKr) was increased. Our results indicate the silent effects of chronic exposure to trace concentrations of lindane on the morphological and electrical activity of heart muscle. They demonstrate that chronic lindane treatment of female rats alters the tissue integrity and electrical activity in the LV of their offspring.Key words: heart muscle, membrane potential, lindane, K+ channel.
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Affiliation(s)
- Martin-Pierre Sauviat
- Institut National de la Santé et de la Recherche Médicale Unité 696-Centre National de la Recherche Scientifique Unité Mixte de Recherche 7654-Ecole Polytechnique, Palaiseau, France.
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21
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Ooi GT, Tawadros N, Escalona RM. Pituitary cell lines and their endocrine applications. Mol Cell Endocrinol 2004; 228:1-21. [PMID: 15541569 DOI: 10.1016/j.mce.2004.07.018] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2004] [Accepted: 07/15/2004] [Indexed: 10/26/2022]
Abstract
The pituitary gland is an important component of the endocrine system, and together with the hypothalamus, exerts considerable influence over the functions of other endocrine glands. The hypothalamus either positively or negatively regulates hormonal productions in the pituitary through its release of various trophic hormones which act on specific cell types in the pituitary to secrete a variety of pituitary hormones that are important for growth and development, metabolism, reproductive and nervous system functions. The pituitary is divided into three sections-the anterior lobe which constitute the majority of the pituitary mass and is composed primarily of five hormone-producing cell types (thyrotropes, lactotropes, corticotropes, somatotropes and gonadotropes) each secreting thyrotropin, prolactin, ACTH, growth hormone and gonadotropins (FSH and LH) respectively. There is also a sixth cell type in the anterior lobe-the non-endocrine, agranular, folliculostellate cells. The intermediate lobe produces melanocyte-stimulating hormone and endorphins, whereas the posterior lobe secretes anti-diuretic hormone (vasopressin) and oxytocin. Representative cell lines of all the six cell types of the anterior pituitary have been established and have provided valuable information on genealogy of the various cell lineages, endocrine feedback control of hormone synthesis and secretions, intrapituitary interactions between the various cell types, as well as the role of specific transcription factors that determine each differentiated cell phenotype. In this review, we will discuss the morphology and function of the cell types that make up the anterior pituitary, and the characteristics of the various functional anterior pituitary cell systems that have been established to be representative of each anterior pituitary cell lineage.
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Affiliation(s)
- Guck T Ooi
- Prince Henry's Institute of Medical Research, Monash Medical Centre, Block E, Level 4, 246 Clayton Road, Clayton, Victoria 3168, Australia.
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