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Griffin AM, Kahlig KM, Hatch RJ, Hughes ZA, Chapman ML, Antonio B, Marron BE, Wittmann M, Martinez-Botella G. Discovery of the First Orally Available, Selective K Na1.1 Inhibitor: In Vitro and In Vivo Activity of an Oxadiazole Series. ACS Med Chem Lett 2021; 12:593-602. [PMID: 33859800 PMCID: PMC8040054 DOI: 10.1021/acsmedchemlett.0c00675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/01/2021] [Indexed: 12/15/2022] Open
Abstract
The gene KCNT1 encodes the sodium-activated potassium channel KNa1.1 (Slack, Slo2.2). Variants in the KCNT1 gene induce a gain-of-function (GoF) phenotype in ionic currents and cause a spectrum of intractable neurological disorders in infants and children, including epilepsy of infancy with migrating focal seizures (EIMFS) and autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). Effective treatment options for KCNT1-related disease are absent, and novel therapies are urgently required. We describe the development of a novel class of oxadiazole KNa1.1 inhibitors, leading to the discovery of compound 31 that reduced seizures and interictal spikes in a mouse model of KCNT1 GoF.
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Affiliation(s)
- Andrew M Griffin
- Praxis Precision Medicines, Research Innovation, Cambridge, Massachusetts 02142, United States
| | - Kristopher M Kahlig
- Praxis Precision Medicines, Research Innovation, Cambridge, Massachusetts 02142, United States
| | - Robert John Hatch
- Praxis Precision Medicines, Research Innovation, Cambridge, Massachusetts 02142, United States
- The Florey Institute of Neuroscience and Mental Health, Melbourne, VIC 3052, Australia
| | - Zoë A Hughes
- Praxis Precision Medicines, Research Innovation, Cambridge, Massachusetts 02142, United States
| | | | | | - Brian E Marron
- Praxis Precision Medicines, Research Innovation, Cambridge, Massachusetts 02142, United States
| | - Marion Wittmann
- Praxis Precision Medicines, Research Innovation, Cambridge, Massachusetts 02142, United States
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2
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Fuller M, Santos SC, Mathes C, Chapman ML, Gerlach A. ΔKPQ Nav1.5 channels for late current cardiac pharmacology assessment. J Pharmacol Toxicol Methods 2018. [DOI: 10.1016/j.vascn.2018.01.398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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3
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Fuller MD, Mathes C, Lin Z, Chapman ML, Brinkwirth N, Haarmann C, George M, Fertig N, Brüggemann A. Development of High throughput Electrophysiology Assays of Recombinant Nav1.9 Channels. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.3426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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4
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Swain NA, Batchelor D, Beaudoin S, Bechle BM, Bradley PA, Brown AD, Brown B, Butcher KJ, Butt RP, Chapman ML, Denton S, Ellis D, Galan SRG, Gaulier SM, Greener BS, de Groot MJ, Glossop MS, Gurrell IK, Hannam J, Johnson MS, Lin Z, Markworth CJ, Marron BE, Millan DS, Nakagawa S, Pike A, Printzenhoff D, Rawson DJ, Ransley SJ, Reister SM, Sasaki K, Storer RI, Stupple PA, West CW. Discovery of Clinical Candidate 4-[2-(5-Amino-1H-pyrazol-4-yl)-4-chlorophenoxy]-5-chloro-2-fluoro-N-1,3-thiazol-4-ylbenzenesulfonamide (PF-05089771): Design and Optimization of Diaryl Ether Aryl Sulfonamides as Selective Inhibitors of NaV1.7. J Med Chem 2017; 60:7029-7042. [DOI: 10.1021/acs.jmedchem.7b00598] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | | | - Serge Beaudoin
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | - Bruce M. Bechle
- Worldwide
Medicinal Chemistry, Pfizer Inc., Eastern Point Road, Groton, Connecticut 06340, United States
| | | | | | | | | | | | - Mark L. Chapman
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | | | | | | | | | | | | | | | | | | | - Matthew S. Johnson
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | - Zhixin Lin
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | | | - Brian E. Marron
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | | | | | | | - David Printzenhoff
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | | | | | - Steven M. Reister
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
| | | | | | | | - Christopher W. West
- Icagen Inc., 4222 Emperor Blvd
no. 350, Durham, North Carolina 27703, United States
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Pryde DC, Swain NA, Stupple PA, West CW, Marron B, Markworth CJ, Printzenhoff D, Lin Z, Cox PJ, Suzuki R, McMurray S, Waldron GJ, Payne CE, Warmus JS, Chapman ML. The discovery of a potent Na v1.3 inhibitor with good oral pharmacokinetics. Medchemcomm 2017; 8:1255-1267. [PMID: 30108836 DOI: 10.1039/c7md00131b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 04/26/2017] [Indexed: 11/21/2022]
Abstract
In this article, we describe the discovery of an aryl ether series of potent and selective Nav1.3 inhibitors. Based on structural analogy to a similar series of compounds we have previously shown bind to the domain IV voltage sensor region of Nav channels, we propose this series binds in the same location. We describe the development of this series from a published starting point, highlighting key selectivity and potency data, and several studies designed to validate Nav1.3 as a target for pain.
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Affiliation(s)
- D C Pryde
- Worldwide Medicinal Chemistry , Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK .
| | - N A Swain
- Worldwide Medicinal Chemistry , Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK .
| | - P A Stupple
- Worldwide Medicinal Chemistry , Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK .
| | - C W West
- Pfizer Neuroscience and Pain Research Unit , 4222 Emperor Boulevard, Suite 350 , Durham , North Carolina NC27703 , USA
| | - B Marron
- Pfizer Neuroscience and Pain Research Unit , 4222 Emperor Boulevard, Suite 350 , Durham , North Carolina NC27703 , USA
| | - C J Markworth
- Pfizer Neuroscience and Pain Research Unit , 4222 Emperor Boulevard, Suite 350 , Durham , North Carolina NC27703 , USA
| | - D Printzenhoff
- Pfizer Neuroscience and Pain Research Unit , 4222 Emperor Boulevard, Suite 350 , Durham , North Carolina NC27703 , USA
| | - Z Lin
- Pfizer Neuroscience and Pain Research Unit , 4222 Emperor Boulevard, Suite 350 , Durham , North Carolina NC27703 , USA
| | - P J Cox
- Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK
| | - R Suzuki
- Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK
| | - S McMurray
- Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK
| | - G J Waldron
- Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK
| | - C E Payne
- Pfizer Neuroscience and Pain Research Unit , Portway Building, Granta Park , Cambridge , CB21 6GS , UK
| | - J S Warmus
- Worldwide Medicinal Chemistry , Pfizer Neuroscience and Pain Research Unit , Groton , CT , USA
| | - M L Chapman
- Pfizer Neuroscience and Pain Research Unit , 4222 Emperor Boulevard, Suite 350 , Durham , North Carolina NC27703 , USA
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Theile JW, Fuller MD, Chapman ML. The Selective Nav1.7 Inhibitor, PF-05089771, Interacts Equivalently with Fast and Slow Inactivated Nav1.7 Channels. Mol Pharmacol 2016; 90:540-548. [PMID: 27587537 DOI: 10.1124/mol.116.105437] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 08/31/2016] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated sodium (Nav) channel inhibitors are used clinically as analgesics and local anesthetics. However, the absence of Nav channel isoform selectivity of current treatment options can result in adverse cardiac and central nervous system side effects, limiting their therapeutic utility. Human hereditary gain- or loss-of-pain disorders have demonstrated an essential role of Nav1.7 sodium channels in the sensation of pain, thus making this channel an attractive target for new pain therapies. We previously identified a novel, state-dependent human Nav1.7 selective inhibitor (PF-05089771, IC50 = 11 nM) that interacts with the voltage-sensor domain (VSD) of domain IV. We further characterized the state-dependent interaction of PF-05089771 by systematically varying the voltage, frequency, and duration of conditioning prepulses to provide access to closed, open, and fast- or slow-inactivated states. The current study demonstrates that PF-05089771 exhibits a slow onset of block that is depolarization and concentration dependent, with a similarly slow recovery from block. Furthermore, the onset of block by PF-05089771 develops with similar rates using protocols that bias channels into predominantly fast- or slow-inactivated states, suggesting that channel inhibition is less dependent on the availability of a particular inactivated state than the relative time that the channel is depolarized. Taken together, the inhibitory profile of PF-05089771 suggests that a conformational change in the domain IV VSD after depolarization is necessary and sufficient to reveal a high-affinity binding site with which PF-05089771 interacts, stabilizing the channel in a nonconducting conformation from which recovery is slow.
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Affiliation(s)
- Jonathan W Theile
- Neusentis US, Pfizer Global R&D, (currently Icagen, Inc.), Durham, North Carolina
| | - Matthew D Fuller
- Neusentis US, Pfizer Global R&D, (currently Icagen, Inc.), Durham, North Carolina
| | - Mark L Chapman
- Neusentis US, Pfizer Global R&D, (currently Icagen, Inc.), Durham, North Carolina
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7
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Alexandrou AJ, Brown AR, Chapman ML, Estacion M, Turner J, Mis MA, Wilbrey A, Payne EC, Gutteridge A, Cox PJ, Doyle R, Printzenhoff D, Lin Z, Marron BE, West C, Swain NA, Storer RI, Stupple PA, Castle NA, Hounshell JA, Rivara M, Randall A, Dib-Hajj SD, Krafte D, Waxman SG, Patel MK, Butt RP, Stevens EB. Subtype-Selective Small Molecule Inhibitors Reveal a Fundamental Role for Nav1.7 in Nociceptor Electrogenesis, Axonal Conduction and Presynaptic Release. PLoS One 2016; 11:e0152405. [PMID: 27050761 PMCID: PMC4822888 DOI: 10.1371/journal.pone.0152405] [Citation(s) in RCA: 131] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 03/14/2016] [Indexed: 01/08/2023] Open
Abstract
Human genetic studies show that the voltage gated sodium channel 1.7 (Nav1.7) is a key molecular determinant of pain sensation. However, defining the Nav1.7 contribution to nociceptive signalling has been hampered by a lack of selective inhibitors. Here we report two potent and selective arylsulfonamide Nav1.7 inhibitors; PF-05198007 and PF-05089771, which we have used to directly interrogate Nav1.7’s role in nociceptor physiology. We report that Nav1.7 is the predominant functional TTX-sensitive Nav in mouse and human nociceptors and contributes to the initiation and the upstroke phase of the nociceptor action potential. Moreover, we confirm a role for Nav1.7 in influencing synaptic transmission in the dorsal horn of the spinal cord as well as peripheral neuropeptide release in the skin. These findings demonstrate multiple contributions of Nav1.7 to nociceptor signalling and shed new light on the relative functional contribution of this channel to peripheral and central noxious signal transmission.
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Affiliation(s)
- Aristos J. Alexandrou
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Adam R. Brown
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Mark L. Chapman
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - Mark Estacion
- Center for Neuroscience & Regeneration Research, Yale Medical School and Veterans Affairs Hospital, West Haven, CT, 06516, United States of America
| | - Jamie Turner
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Malgorzata A. Mis
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Anna Wilbrey
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Elizabeth C. Payne
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Alex Gutteridge
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Peter J. Cox
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Rachel Doyle
- Pfizer Global R&D, Ramsgate Road, Sandwich, Kent, CT13 9NJ, United Kingdom
| | - David Printzenhoff
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - Zhixin Lin
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - Brian E. Marron
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - Christopher West
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - Nigel A. Swain
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - R. Ian Storer
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Paul A. Stupple
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
| | - Neil A. Castle
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - James A. Hounshell
- Dept. Anesthesiology, University of Virginia Health System, Charlottesville, Virginia, 22911, United States of America
| | - Mirko Rivara
- Dept. Anesthesiology, University of Virginia Health System, Charlottesville, Virginia, 22911, United States of America
| | - Andrew Randall
- Medical School, Hatherly Building, University of Exeter, Prince of Wales Road, Exeter, EX4 4PS, United Kingdom
| | - Sulayman D. Dib-Hajj
- Center for Neuroscience & Regeneration Research, Yale Medical School and Veterans Affairs Hospital, West Haven, CT, 06516, United States of America
| | - Douglas Krafte
- Pfizer Neusentis, 4222 Emperor Boulevard, Durham, North Carolina, 27703, United States of America
| | - Stephen G. Waxman
- Center for Neuroscience & Regeneration Research, Yale Medical School and Veterans Affairs Hospital, West Haven, CT, 06516, United States of America
| | - Manoj K. Patel
- Dept. Anesthesiology, University of Virginia Health System, Charlottesville, Virginia, 22911, United States of America
| | - Richard P. Butt
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
- * E-mail: (EBS); (RPB)
| | - Edward B. Stevens
- Pfizer Neusentis, The Portway Buiding, Granta Park, Great Abington, Cambridge, CB21 6GS, United Kingdom
- * E-mail: (EBS); (RPB)
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8
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Fuller MD, Santos S, Chapman ML. Identification of Novel Pore Interactions for Selective Nav1.8 Inhibitors. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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9
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Payne CE, Brown AR, Theile JW, Loucif AJC, Alexandrou AJ, Fuller MD, Mahoney JH, Antonio BM, Gerlach AC, Printzenhoff DM, Prime RL, Stockbridge G, Kirkup AJ, Bannon AW, England S, Chapman ML, Bagal S, Roeloffs R, Anand U, Anand P, Bungay PJ, Kemp M, Butt RP, Stevens EB. A novel selective and orally bioavailable Nav 1.8 channel blocker, PF-01247324, attenuates nociception and sensory neuron excitability. Br J Pharmacol 2015; 172:2654-70. [PMID: 25625641 DOI: 10.1111/bph.13092] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 01/13/2015] [Accepted: 01/14/2015] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND AND PURPOSE NaV 1.8 ion channels have been highlighted as important molecular targets for the design of low MW blockers for the treatment of chronic pain. Here, we describe the effects of PF-01247324, a new generation, selective, orally bioavailable Nav 1.8 channel blocker of novel chemotype. EXPERIMENTAL APPROACH The inhibition of Nav 1.8 channels by PF-01247324 was studied using in vitro patch-clamp electrophysiology and the oral bioavailability and antinociceptive effects demonstrated using in vivo rodent models of inflammatory and neuropathic pain. KEY RESULTS PF-01247324 inhibited native tetrodotoxin-resistant (TTX-R) currents in human dorsal root ganglion (DRG) neurons (IC50 : 331 nM) and in recombinantly expressed h Nav 1.8 channels (IC50 : 196 nM), with 50-fold selectivity over recombinantly expressed TTX-R hNav 1.5 channels (IC50 : ∼10 μM) and 65-100-fold selectivity over TTX-sensitive (TTX-S) channels (IC50 : ∼10-18 μM). Native TTX-R currents in small-diameter rodent DRG neurons were inhibited with an IC50 448 nM, and the block of both human recombinant Nav 1.8 channels and TTX-R from rat DRG neurons was both frequency and state dependent. In vitro current clamp showed that PF-01247324 reduced excitability in both rat and human DRG neurons and also altered the waveform of the action potential. In vivo experiments n rodents demonstrated efficacy in both inflammatory and neuropathic pain models. CONCLUSIONS AND IMPLICATIONS Using PF-01247324, we have confirmed a role for Nav 1.8 channels in both inflammatory and neuropathic pain. We have also demonstrated a key role for Nav 1.8 channels in action potential upstroke and repetitive firing of rat and human DRG neurons.
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10
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Bagal SK, Chapman ML, Marron BE, Prime R, Storer RI, Swain NA. Recent progress in sodium channel modulators for pain. Bioorg Med Chem Lett 2014; 24:3690-9. [PMID: 25060923 DOI: 10.1016/j.bmcl.2014.06.038] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 06/11/2014] [Accepted: 06/12/2014] [Indexed: 01/15/2023]
Abstract
Voltage-gated sodium channels (Navs) are an important family of transmembrane ion channel proteins and Nav drug discovery is an exciting field. Pharmaceutical investment in Navs for pain therapeutics has expanded exponentially due to genetic data such as SCN10A mutations and an improved ability to establish an effective screen sequence for example IonWorks Barracuda®, Synchropatch® and Qube®. Moreover, emerging clinical data (AZD-3161, XEN402, CNV1014802, PF-05089771, PF-04531083) combined with recent breakthroughs in Nav structural biology pave the way for a future of fruitful prospective Nav drug discovery.
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Affiliation(s)
- Sharan K Bagal
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge CB21 6GS, UK.
| | - Mark L Chapman
- Electrophysiology, Pfizer Neusentis, 4222 Emperor Blvd., Durham, NC, USA
| | - Brian E Marron
- Chemistry, Pfizer Neusentis, 4222 Emperor Blvd., Durham, NC, USA
| | - Rebecca Prime
- Electrophysiology, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge CB21 6GS, UK
| | - R Ian Storer
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge CB21 6GS, UK
| | - Nigel A Swain
- Worldwide Medicinal Chemistry, Pfizer Neusentis, The Portway Building, Granta Park, Great Abington, Cambridge CB21 6GS, UK
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Iglesias-Soler E, Carballeira E, Sánchez-Otero T, Mayo X, Jiménez A, Chapman ML. Acute effects of distribution of rest between repetitions. Int J Sports Med 2012; 33:351-8. [PMID: 22318560 DOI: 10.1055/s-0031-1299699] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The purpose of this study was to compare acute mechanical and metabolic effects of 2 sessions of resistance training equated by volume and total resting time but with different set configuration: sets to failure (FS) vs. distribution of rest between each repetition (NFS). 10 male judoists completed a session consisting of 3 sets to failure of parallel back squat with 4 repetitions at maximum load, and a rest of 3 min between the sets. At least 72 h later subjects developed the same volume, but total resting time was distributed among individual repetitions. Before and after sessions isometric force and mean propulsive velocity with load corresponding to maximum propulsive power were assessed. Results showed that in respect to FS, NFS showed an 18.94% (± 17.98) higher average mean propulsive velocity during session (0.42 ± 0.04 vs. 0.35 ± 0.08 m.s - 1; p=0.009), lower blood lactate concentration after session (maximum average value 1.52 ± 0.77 vs. 3.95 ± 1.82; session effect: p=0.001) and higher mean propulsive velocity with load corresponding to maximum propulsive power (mean propulsive velocity immediately after session 0.64 ± 0.09 vs. 0.59 ± 0.12 m.s - 1; session effect: p=0.019). These data show that distribution of rest in sessions equated for volume and total resting time determines differences in performance during sessions and mechanical or metabolic acute effects.
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Affiliation(s)
- E Iglesias-Soler
- University of A Coruña, Physical Education and Sports, Oleiros, Spain.
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Kort ME, Atkinson RN, Thomas JB, Drizin I, Johnson MS, Secrest MA, Gregg RJ, Scanio MJ, Shi L, Hakeem AH, Matulenko MA, Chapman ML, Krambis MJ, Liu D, Shieh CC, Zhang X, Simler G, Mikusa JP, Zhong C, Joshi S, Honore P, Roeloffs R, Werness S, Antonio B, Marsh KC, Faltynek CR, Krafte DS, Jarvis MF, Marron BE. Subtype-selective Nav1.8 sodium channel blockers: Identification of potent, orally active nicotinamide derivatives. Bioorg Med Chem Lett 2010; 20:6812-5. [DOI: 10.1016/j.bmcl.2010.08.121] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Accepted: 08/24/2010] [Indexed: 12/19/2022]
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13
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Scanio MJC, Shi L, Drizin I, Gregg RJ, Atkinson RN, Thomas JB, Johnson MS, Chapman ML, Liu D, Krambis MJ, Liu Y, Shieh CC, Zhang X, Simler GH, Joshi S, Honore P, Marsh KC, Knox A, Werness S, Antonio B, Krafte DS, Jarvis MF, Faltynek CR, Marron BE, Kort ME. Discovery and biological evaluation of potent, selective, orally bioavailable, pyrazine-based blockers of the Na(v)1.8 sodium channel with efficacy in a model of neuropathic pain. Bioorg Med Chem 2010; 18:7816-25. [PMID: 20965738 DOI: 10.1016/j.bmc.2010.09.057] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Revised: 09/16/2010] [Accepted: 09/22/2010] [Indexed: 11/29/2022]
Abstract
Na(v)1.8 (also known as PN3) is a tetrodotoxin-resistant (TTx-r) voltage-gated sodium channel (VGSC) that is highly expressed on small diameter sensory neurons. It has been implicated in the pathophysiology of inflammatory and neuropathic pain, and we envisioned that selective blockade of Na(v)1.8 would be analgesic, while reducing adverse events typically associated with non-selective VGSC blocking therapeutic agents. Herein, we describe the preparation and characterization of a series of 6-aryl-2-pyrazinecarboxamides, which are potent blockers of the human Na(v)1.8 channel and also block TTx-r sodium currents in rat dorsal root ganglia (DRG) neurons. Selected derivatives display selectivity versus human Na(v)1.2. We further demonstrate that an example from this series is orally bioavailable and produces antinociceptive activity in vivo in a rodent model of neuropathic pain following oral administration.
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Affiliation(s)
- Marc J C Scanio
- Global Pharmaceutical Research and Development, Abbott Laboratories, Dept R4PM, Bldg. AP9A, 100 Abbott Park Road, Abbott Park, IL 60064-6117, United States.
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Su X, Castle NA, Antonio B, Roeloffs R, Thomas JB, Krafte DS, Chapman ML. The Effect of κ-Opioid Receptor Agonists on Tetrodotoxin-Resistant Sodium Channels in Primary Sensory Neurons. Anesth Analg 2009; 109:632-40. [DOI: 10.1213/ane.0b013e3181a909a4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Smith PM, Chapman ML, Hazlehurst KE, Goss-Sampson MA. Erratum to “The influence of crank configuration on muscle activity and torque production during arm crank ergometry” [J. Electromyogr. Kines. 18 (2008) 598–605]. J Electromyogr Kinesiol 2009. [DOI: 10.1016/j.jelekin.2008.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Smith PM, Chapman ML, Hazlehurst KE, Goss-Sampson MA. The influence of crank configuration on muscle activity and torque production during arm crank ergometry. J Electromyogr Kinesiol 2008; 18:598-605. [PMID: 17337211 DOI: 10.1016/j.jelekin.2006.12.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2006] [Revised: 11/08/2006] [Accepted: 12/01/2006] [Indexed: 11/23/2022] Open
Abstract
This study investigated the effect of crank configuration on muscle activity and torque production during submaximal arm crank ergometry. Thirteen non-specifically trained male participants volunteered. During the research trials they completed a warm-up at 15W before two 3-min exercise stages were completed at 50 and 100W; subjects used either a synchronous or asynchronous pattern of cranking. During the final 30-s of each submaximal exercise stage electromyographic and torque production data were collected. After the data had been processed each parameter was analysed using separate 2-way ANOVA tests with repeated measures. The activity of all muscles increased in line with external workload, although a shift in the temporal pattern of muscle activity was noted between crank configurations. Patterns of torque production during asynchronous and synchronous cranking were distinct. Furthermore, peak, minimum and delta (peak-minimum) torque values were different (P<0.05) between crank configurations at both workloads. For example, at 100W, peak torque using synchronous [19.6 (4.3) Nm] cranking was higher (P<0.05) compared to asynchronous [16.8 (1.6) Nm] cranking. In contrast minimum torque was lower (P<0.05) at 100 W using synchronous [4.8 (1.7)Nm] compared to asynchronous [7.3 (1.2)Nm] cranking. There was a distinct bilateral asymmetry in torque production during asynchronous cranking with the dominant transmitting significantly more force to the crank arm. Taken together, these preliminary data demonstrate the complex nature of muscle activity during arm crank ergometry performed with an asynchronous or synchronous crank set-up. Further work is required to determine how muscle activity (EMG activity) and associated patterns of torque production influence physiological responses and functional capacity during arm crank ergometry.
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Affiliation(s)
- Paul M Smith
- Cardiff School of Sport, Ysgol Chwaraeon Caerdydd, University of Wales Institute, Cardiff Cyncoed, CF23 6XD, Wales, United Kingdom [corrected]
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Drizin I, Gregg RJ, Scanio MJC, Shi L, Gross MF, Atkinson RN, Thomas JB, Johnson MS, Carroll WA, Marron BE, Chapman ML, Liu D, Krambis MJ, Shieh CC, Zhang X, Hernandez G, Gauvin DM, Mikusa JP, Zhu CZ, Joshi S, Honore P, Marsh KC, Roeloffs R, Werness S, Krafte DS, Jarvis MF, Faltynek CR, Kort ME. Discovery of potent furan piperazine sodium channel blockers for treatment of neuropathic pain. Bioorg Med Chem 2008; 16:6379-86. [PMID: 18501613 DOI: 10.1016/j.bmc.2008.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2008] [Revised: 04/30/2008] [Accepted: 05/02/2008] [Indexed: 11/18/2022]
Abstract
The synthesis and pharmacological characterization of a novel furan-based class of voltage-gated sodium channel blockers is reported. Compounds were evaluated for their ability to block the tetrodotoxin-resistant sodium channel Na(v)1.8 (PN3) as well as the Na(v)1.2 and Na(v)1.5 subtypes. Benchmark compounds from this series possessed enhanced potency, oral bioavailability, and robust efficacy in a rodent model of neuropathic pain, together with improved CNS and cardiovascular safety profiles compared to the clinically used sodium channel blockers mexiletine and lamotrigine.
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Affiliation(s)
- Irene Drizin
- Neuroscience Research, Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064, USA.
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18
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Kort ME, Drizin I, Gregg RJ, Scanio MJC, Shi L, Gross MF, Atkinson RN, Johnson MS, Pacofsky GJ, Thomas JB, Carroll WA, Krambis MJ, Liu D, Shieh CC, Zhang X, Hernandez G, Mikusa JP, Zhong C, Joshi S, Honore P, Roeloffs R, Marsh KC, Murray BP, Liu J, Werness S, Faltynek CR, Krafte DS, Jarvis MF, Chapman ML, Marron BE. Discovery and biological evaluation of 5-aryl-2-furfuramides, potent and selective blockers of the Nav1.8 sodium channel with efficacy in models of neuropathic and inflammatory pain. J Med Chem 2008; 51:407-16. [PMID: 18176998 DOI: 10.1021/jm070637u] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Nav1.8 (also known as PN3) is a tetrodotoxin-resistant (TTx-r) voltage-gated sodium channel (VGSC) that is highly expressed on small diameter sensory neurons and has been implicated in the pathophysiology of inflammatory and neuropathic pain. Recent studies using an Nav1.8 antisense oligonucleotide in an animal model of chronic pain indicated that selective blockade of Nav1.8 was analgesic and could provide effective analgesia with a reduction in the adverse events associated with nonselective VGSC blocking therapeutic agents. Herein, we describe the preparation and characterization of a series of 5-substituted 2-furfuramides, which are potent, voltage-dependent blockers (IC50 < 10 nM) of the human Nav1.8 channel. Selected derivatives, such as 7 and 27, also blocked TTx-r sodium currents in rat dorsal root ganglia (DRG) neurons with comparable potency and displayed >100-fold selectivity versus human sodium (Nav1.2, Nav1.5, Nav1.7) and human ether-a-go-go (hERG) channels. Following systemic administration, compounds 7 and 27 dose-dependently reduced neuropathic and inflammatory pain in experimental rodent models.
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Affiliation(s)
- Michael E Kort
- Global Pharmaceutical Research and Development, Abbott Laboratories, Abbott Park, IL 60064-6100, USA.
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19
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Abstract
Voltage-gated K channels assemble from four identical subunits symmetrically arranged around a central permeation pathway. Each subunit harbors a voltage-sensing domain. The sigmoidal nature of the activation kinetics suggests that multiple sensors need to undergo a conformational change before the channel can open. Following activation, individual K channels alternate stochastically between two main permeation states, open and closed. This binary character of single channel behavior suggests the presence of a structure in the permeation pathway that can exist in only two conformations. However, single channel analysis of drk1 (K(v)2.1) K channels demonstrated the existence of four additional, intermediate conductance levels. These short-lived subconductance levels are visited when the channel gate moves between the closed and fully open state. We have proposed that these sublevels arise from transient heteromeric pore conformations, in which some, but not all, subunits are in the "open" state. A minimal model based on this hypothesis relates specific subconductance states with the number of activated subunits (Chapman et al., 1997). To stringently test this hypothesis, we constructed a tandem dimer that links two K channel subunits with different activation thresholds. Activation of this dimer by strong depolarizations resulted in the characteristic binary open-close behavior. However, depolarizations to membrane potentials in between the activation thresholds of the two parents elicited highly unusual single channel gating, displaying frequent visits to two subconductance levels. The voltage dependence and kinetics of the small and large sublevels associate them with the activation of one and two subunits, respectively. The data therefore support the hypothesis that subconductance levels result from heteromeric pore conformations. In this model, both sensor movement and channel opening have a subunit basis and these processes are allosterically coupled.
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Affiliation(s)
- Mark L Chapman
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Chapman ML, Blanke ML, Krovetz HS, VanDongen AMJ. Allosteric effects of external K+ ions mediated by the aspartate of the GYGD signature sequence in the Kv2.1 K+ channel. Pflugers Arch 2005; 451:776-92. [PMID: 16283201 DOI: 10.1007/s00424-005-1515-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2005] [Revised: 08/12/2005] [Accepted: 08/31/2005] [Indexed: 11/30/2022]
Abstract
K+ channels achieve exquisite ion selectivity without jeopardizing efficient permeation by employing multiple, interacting K+-binding sites. Introduction ofa cadmium (Cd2+)-binding site in the external vestibule of Kv2.1 (drk1), allowed us to functionally characterize a binding site for external monovalent cations. Permeant ions displayed higher affinity for this site than non-permeant monovalent cations, although the selectivity profile was different from that of the channel. Point mutations identified the highly conserved aspartate residue immediately following the selectivity filter as a critical determinant of the antagonism between external K+ and Cd2+ ions. A conservative mutation at this position (D378E) significantly affected the open-state stability. Moreover, the mean open time was found to be modulated by external K+ concentration, suggesting a coupling between channel closing and the permeation process. Reducing the Rb+ conductance by mutating the selectivity filter to the sequence found inKv4.1, also significantly reduced the effectiveness ofRb+ ions to antagonize Cd2+ inhibition, thereby implicating the selectivity filter as the site at which K+ions exert their antagonistic effect on Cd2+ block. The equivalent of D378 in KcsA, D80, takes part in an inter-subunit hydrogen-bond network that allows D80to functionally interact with the selectivity filter. The results suggest that external K+ ions antagonize Cd2+inhibition (in I379C) and modulate the mean open time(in the wild-type Kv2.1) by altering the occupancy profile of the K+-binding sites in the selectivity filter.
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Affiliation(s)
- Mark L Chapman
- Department of Pharmacology, Duke University, Durham, NC, USA.
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Moskovitz DN, Bodian C, Chapman ML, Marion JF, Rubin PH, Scherl E, Present DH. The effect on the fetus of medications used to treat pregnant inflammatory bowel-disease patients. Am J Gastroenterol 2004; 99:656-61. [PMID: 15089898 DOI: 10.1111/j.1572-0241.2004.04140.x] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVES We reviewed data to investigate the effect of 5-ASA drugs, metronidazole, ciprofloxacin, prednisone, 6-mercaptopurine, azathioprine, and cyclosporine on pregnancy outcomes in patients with inflammatory bowel disease (IBD). METHODS One hundred and thirteen female patients with a total of 207 documented conceptions were studied. Treatment information included: smoking history (patient and spouse), dates of conception and termination, and outcome of pregnancy (spontaneous abortion, therapeutic abortion, maternal or fetal illness resulting in abortion, premature birth, healthy full-term birth, multiple births, ectopic pregnancy, congenital defects), weight of baby, type of delivery (cesarian section, vaginal), medication history during each trimester (mean dose, maximum dose, frequency). We analyzed the effect on pregnancy outcome of medication use during the first trimester or at any time during the pregnancy. RESULTS Thirty-nine patients (34.5%) had ulcerative colitis (UC), 73 (64.5%) had crohn's disease (CD), and 1 patient (1%) had indeterminate colitis. For 100 of the 207 conceptions, the patients were on 5-ASA drugs at some time during the pregnancy, 49 on prednisone, 101 on an immunomodulator (6-MP/azathioprine), 27 on metronidazole, 18 on ciprofloxacin, and 2 on cyclosporine. In 85 (31%) of the conceptions, patients were on none of these medications. No significant differences were found among the groups in each pregnancy with respect to outcome (p values 0.091 to 0.9). In multivariate analyses controlling for age of mother, there was no evidence that 5-ASA type drugs or any type of drug influenced pregnancy outcome. CONCLUSIONS In 113 female patients with 207 conceptions none of the drugs used to treat IBD is associated with poor pregnancy outcomes.
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22
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Abstract
Cells maintain a negative resting membrane potential through the constitutive activity of background K+ channels. A novel multigene family of such K+ channels has recently been identified. A unique characteristic of these K+ channels is the presence of two homologous, subunit-like domains, each containing a pore-forming region. Sequence co-variations in the GYGD signature motifs of the two pore regions suggested an interaction between neighbouring pore domains. Mutations of the GYGD motif in the rat drk1 (Kv2.1) K+ channel showed that the tyrosine (Y) position was important for K+ selectivity and single channel conductance, whereas the aspartate (D) position was a critical determinant of open state stability. Tandem constructs engineered to mimic the GYGx-GxGD pattern seen in two-domain K+ channels delineated a co-operative intersubunit interaction between the Y and D positions, which determined ion selectivity, conductance and gating. In the bacterial KcsA K+ channel crystal structure, the equivalent aspartate residue (D80) does not directly interact with permeating K+ ions. However, the data presented here show that the D position is able to fine-tune ion selectivity through a functional interaction with the Y position in the neighbouring subunit. These data indicate a physiological basis for the extensive sequence variation seen in the GYGD motifs of two-domain K+ channels. It is suggested that a cell can precisely regulate its resting membrane potential by selectively expressing a complement of two-domain K+ channels.
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Affiliation(s)
- M L Chapman
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, PO Box 3813, Durham, NC 27708, USA
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23
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Chapman ML, VanDongen HM, VanDongen AM. Activation-dependent subconductance levels in the drk1 K channel suggest a subunit basis for ion permeation and gating. Biophys J 1997; 72:708-19. [PMID: 9017198 PMCID: PMC1185596 DOI: 10.1016/s0006-3495(97)78707-1] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Ion permeation and channel opening are two fundamental properties of ion channels, the molecular bases of which are poorly understood. Channels can exist in two permeability states, open and closed. The relative amount of time a channel spends in the open conformation depends on the state of activation. In voltage-gated ion channels, activation involves movement of a charged voltage sensor, which is required for channel opening. Single-channel recordings of drk1 K channels expressed in Xenopus oocytes suggested that intermediate current levels (sublevels) may be associated with transitions between the closed and open states. Because K channels are formed by four identical subunits, each contributing to the lining of the pore, it was hypothesized that these sublevels resulted from heteromeric pore conformations. A formal model based on this hypothesis predicted that sublevels should be more frequently observed in partially activated channels, in which some but not all subunits have undergone voltage-dependent conformational changes required for channel opening. Experiments using the drk1 K channel, as well as drk1 channels with mutations in the pore and in the voltage sensor, showed that the probability of visiting a sublevel correlated with voltage- and time-dependent changes in activation. A subunit basis is proposed for channel opening and permeation in which these processes are coupled.
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Affiliation(s)
- M L Chapman
- Department of Pharmacology, Duke University Medical Center, Durham, North Carolina 27710, USA
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24
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Abstract
A single dose of the organophosphate insecticide O,O'-diethyl-O-3,5,6- trichloro-2-pyridylphosphorothioate [chlorpyrifos (CPF), 279 mg/kg, SC] caused extensive inhibition of cortical and striatal cholinesterase (ChE) activity in adult rats at 2 (94-96%), 4 (82-83%), and 6 (58-60%) weeks after treatment. These persistent changes in ChE activity were concomitant with reductions in muscarinic receptor binding sites in cortex (34, 33, and 18% reduction in Bmax) and striatum (48, 40, and 23% reduction in Bmax) at 2, 4, and 6 weeks after exposure. Neither ChE activities nor muscarinic receptor densities were different from control levels at 12 weeks after exposure. CPF treatment caused a reduction in locomotor activity for the first 2 days after treatment, after which basal activity levels were not different from controls. CPF-treated rats showed higher activity relative to controls, however, following challenge with scopolamine (1 mg/kg, IP) at 2, 4, 6, 8, and 12 weeks after treatment. These data indicate that acute exposure to CPF in adult rats can cause long-term neurobehavioral changes that may persist following the recovery of neurochemical parameters associated with exposure and tolerance to cholinesterase inhibitors.
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Affiliation(s)
- C N Pope
- Division of Pharmacology and Toxicology, School of Pharmacy, Northeast Louisiana University, Monroe 71209-0470
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25
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Gracy RW, Yüksel KU, Jacobson TM, Chapman ML, Hevelone JC, Wise GE, Dimitrijevich SD. Cellular models and tissue equivalent systems for evaluating the structures and significance of age-modified proteins. Gerontology 1991; 37:113-27. [PMID: 2055495 DOI: 10.1159/000213254] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The accumulation of modified proteins in aging is well documented in many aging models. For example, the deamidated isoforms of triosephosphate isomerase accumulate in: (a) old erythrocytes, (b) fibroblasts from old donors, (c) fibroblasts aged in vitro, (d) premature-aging syndromes and (e) old cells in the eye lens. However, a fundamental remaining question is: 'Do such modified proteins interfere with cellular function?' It has been difficult to assess this question at the molecular level using whole-organism models and equally frustrating to evaluate the physiological significance of such changes using classical cellular models. Tissue equivalent systems (TES) provide an opportunity for examining the molecular basis and physiological consequences of modified proteins during aging. TES are composed of differentiating and proliferating heterogeneous cell types with symbiotic cell-cell and cell-matrix interactions. They closely resemble, both morphologically and functionally, the tissues from which they were derived. Aging studies utilizing TES can provide information on modifications of protein structures, isozyme patterns, enzymes of the cellular environmental protection system and metabolic parameters which may regulate protein synthesis and degradation.
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Affiliation(s)
- R W Gracy
- Department of Biochemistry, University of North Texas/Texas College of Osteopathic Medicine, Fort Worth
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26
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Pope CN, Chakraborti TK, Chapman ML, Farrar JD, Arthun D. Comparison of in vivo cholinesterase inhibition in neonatal and adult rats by three organophosphorothioate insecticides. Toxicology 1991; 68:51-61. [PMID: 1714639 DOI: 10.1016/0300-483x(91)90061-5] [Citation(s) in RCA: 189] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Developing mammals are more sensitive than adults to a variety of organophosphorothioate insecticides (OPs), compounds which act in vivo by inhibition of cholinesterase (ChE). Little is known, however, regarding age-related differences in biochemical responses to these toxicants. The time course of ChE inhibition and recovery in whole brain was compared in neonatal (7 days of age) and adult (80-100 days of age) rats after treatment with maximal tolerated doses (MTDs) of either methyl parathion (MPS), parathion (PS) or chlorpyrifos (CPF). Neonatal rats were more sensitive than adults in all cases (MTDs for MPS, PS and CPF; neonates = 7.8, 2.1 and 45 mg/kg, s.c.; adults = 18, 18, and 279 mg/kg, s.c., respectively). In general, maximal brain ChE inhibition was similar (greater than 78%) in both age groups but ChE activity recovered faster in neonates. Plasma and erythrocyte ChE activities correlated relatively well (r = 0.794-0.943) with brain ChE activity in neonatal rats at all time points between 4 h and 7 days after treatment but similar correlations between circulating and brain ChE activities in adults were more variable (r = 0.211-0.917). The results indicate that neonatal rats are more sensitive to acute lethality from these compounds and that MTD exposures produce extensive brain ChE inhibition in both age groups. Significant inhibitor-related and age-related differences in the duration of ChE inhibition can ensue, however, following such OP exposures.
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Affiliation(s)
- C N Pope
- Department of Pharmacology and Toxicology, School of Pharmacy, Northeast Louisiana University, Monroe 71209
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27
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Chapman ML, Dimitrijevich SD, Hevelone JC, Goetz D, Cohen J, Wise GE, Gracy RW. Inhibition of psoriatic cell proliferation in in vitro skin models by amiprilose hydrochloride. In Vitro Cell Dev Biol 1990; 26:991-6. [PMID: 2243063 DOI: 10.1007/bf02624474] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Amiprilose hydrochloride, a 3-substituted glucose derivative, was found to inhibit the proliferation of human fibroblasts and keratinocytes originating from psoriatic lesions. Fibroblasts and keratinocytes were obtained from skin biopsies of normal donors, and from the biopsies of active/involved and uninvolved sites of psoriatic donors. The cells were cultured as monolayers or as components of tissue equivalent models. Keratinocytes and fibroblasts originating from biopsies of psoriatically involved areas were shown to proliferate at a significantly higher rate than those derived from uninvolved areas. The antiproliferative effect of amiprilose hydrochloride was not observed with normal keratinocytes or fibroblasts from the skin of healthy donors or from uninvolved areas of psoriatic donors. Amiprilose hydrochloride was not cytotoxic to any of these cells at levels below 0.1%. The combination of the low cytotoxicity and the selective antiproliferative effect indicates that this compound may be a useful antipsoriatic agent. The use of monolayer cultures and tissue equivalent models in this study illustrates the utility of such a progressive strategy in the evaluation of potential topical pharmaceuticals.
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Affiliation(s)
- M L Chapman
- Department of Biochemistry, University of North Texas/Texas College of Osteopathic Medicine, Fort Worth 76109
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Kornbluth AA, Salomon P, Sachar DB, Subramani K, Kramer A, Gray CE, Present DH, Chapman ML. ACTH-induced adrenal hemorrhage: a complication of therapy masquerading as an acute abdomen. J Clin Gastroenterol 1990; 12:371-7. [PMID: 1975815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Four patients developed adrenal hemorrhage during treatment with intravenous adrenocorticotropic hormone (ACTH) for severe inflammatory bowel disease (IBD). This complication presented suddenly with upper abdominal and flank pain mimicking an acute surgical abdomen. In each patient the symptoms of the underlying bowel disease had subsided under the ACTH therapy. In our first patient the diagnosis was not made until laparotomy, but in the subsequent three patients the diagnosis was suspected by the strikingly similar clinical presentation. In each of these three latter patients the diagnosis was confirmed by sonography or computed tomography (CT) scan, and surgery was avoided. All four of our patients are doing well at 1-58 months of follow-up. Signs of adrenal insufficiency occurred only in the one of our four patients, and in those six of 11 previously reported patients, who had bilateral adrenal hemorrhage. ACTH-induced adrenal hemorrhage requires stopping ACTH and maintaining corticosteroid support. The diagnosis of adrenal hemorrhage should be considered in the patient treated with ACTH who develops unexplained acute abdominal or flank pain. Failure to recognize this complication of ACTH therapy can lead to unnecessary surgery or the dangerous continuation of the offending agent.
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Affiliation(s)
- A A Kornbluth
- Department of Medicine, Mount Sinai School of Medicine, City University of New York, New York
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29
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Chapman ML, Rubin BR, Gracy RW. Increased carbonyl content of proteins in synovial fluid from patients with rheumatoid arthritis. J Rheumatol Suppl 1989; 16:15-8. [PMID: 2716005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The carbonyl content of proteins in the synovial fluid (SF) of patients with rheumatoid arthritis was significantly (p less than or equal to 0.10) elevated over levels in the SF of patients with osteoarthritis (OA). Other indicators of oxidative damage including catalse, ceruloplasmin, ferritin and superoxide dismutase also showed statistically significant differences (p less than or equal to 0.05) compared to patients with OA.
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Affiliation(s)
- M L Chapman
- Department of Biochemistry, University of North Texas 76107-2690
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30
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Present DH, Wolfson D, Gelernt IM, Rubin PH, Bauer J, Chapman ML. Medical decompression of toxic megacolon by "rolling". A new technique of decompression with favorable long-term follow-up. J Clin Gastroenterol 1988; 10:485-90. [PMID: 3183326 DOI: 10.1097/00004836-198810000-00004] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We treated 19 consecutive patients with toxic megacolon complicating inflammatory bowel disease with the usual intensive medical regimen, but also added a new technique, namely, the frequent rolling of the patient to the prone position in order to redistribute colonic gas and thereby promote decompression. In all 19 patients (100%) the colon was decompressed within 1-13 days (mean 4.9 days). Two patients (10.5%) died. In long-term follow-up (mean 6.5 years), only 4 of the 17 survivors (21%) ultimately required colectomy; the remaining 13 (68%) were either completely well or only minimally symptomatic and did not require steroids. Most reports on the management of toxic megacolon stress the need for early surgical intervention, but our success in decompression with the addition of the "rolling technique" suggests an improvement in the nonoperative management of toxic megacolon.
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Affiliation(s)
- D H Present
- Mount Sinai Medical Center, Department of Medicine and Surgery, New York, New York
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31
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Chapman ML, Rubin BR, Gracy RW. The redox state in lymphocytes from patients with rheumatoid arthritis. J Rheumatol 1986; 13:850-2. [PMID: 3820194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Our study was designed to quantitate levels of NAD+, NADH, NADP(H), and ATP in peripheral blood lymphocytes with and without mitogenic stimulation from patients with rheumatoid arthritis (RA). No differences were found in patients with RA and healthy controls. Our data suggest the ability of the redox system of circulating peripheral lymphocytes to respond to mitogenic stimulation in patients with RA is not markedly impaired.
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32
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Gracy RW, Chapman ML, Cini JK, Jahani M, Tollefsbol TO, Yüksel KU. Molecular basis of the accumulation of abnormal proteins in progeria and aging fibroblasts. Basic Life Sci 1985; 35:427-42. [PMID: 4062822 DOI: 10.1007/978-1-4899-2218-2_27] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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33
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Abstract
NAD levels markedly increase upon mitogen stimulation of lymphocytes from young subjects. In contrast, lymphocytes from old subjects do not increase NAD levels upon stimulation. A survey of 35 individuals aged 18-79 years revealed a significant age-dependent decrease in the NAD response to mitogen stimulation. No significant differences were noted in lymphocytes from age-matched individuals with Down's syndrome or diabetes mellitus. On the other hand, cultured skin fibroblasts showed elevated NAD levels with age. However, this effect appears to be due to increased size of the cells since the NAD/protein ratio is unchanged. Skin fibroblasts from patients with progeria exhibit much higher levels of NAD and protein per cell than age-matched controls.
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34
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Abstract
When peripheral lymphocytes from young persons are stimulated in vitro with phytohemagglutinin, an increase in the levels of all the glycolytic enzymes occurs concomitantly with blastogenesis. The specific activities of enzymes increase approximately 200%, with a greater induction of the latter half of the pathway. The increases do not represent a general enzyme induction, since nonglycolytic enzymes such as glucose 6-phosphate dehydrogenase and isocitrate dehydrogenase do not increase during transformation. Human lymphocytes from a geriatric population were also subjected to mitogen stimulation under identical conditions. The initial levels of the enzymes were essentially identical in lymphocytes from young and old subjects as were cultured controls which received no mitogen. However, during mitogen stimulation the cells from the old subjects failed to increase the glycolytic enzymes. This inability to activate glycolysis may be related to the decline in cell-mediated immunity which is known to occur with advancing age.
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Chapman ML. Teaching patient care: a reply. Radiol Technol 1979; 50:453-4. [PMID: 441293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Chapman ML, Janowitz HD. Pyloroduodenal dysfunction and dyspepsia in relation to gastritis and ulcer. Clin Gastroenterol 1977; 6:581-96. [PMID: 336247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Abstract
Alterations in composition of isosmotic acid solutions were studied in exteriorized segments of the proximal (Brunner's gland area) and distal canine duodenum, mounted in lucite chambers. Varying concentrations of HCl (40, 80, 120, 160 mEq/l) made isotonic by the addition of NaCl were instilled into the chamber, removed in 15 minutes and analyzed for volume, electrolytes, protein content and osmolality. Both proximal and distal duodenal mucosa modified the instilled solution with a loss of H+ and a gain in Na+ and K+, which occurred at similar rates independent of the acid concentration of the instilled solution. The rate of ionic movement was twice that for the antrum, and 30-100 times that of the fundus. Calculated H+ loss across the entire duodenal mucosa at these rates could account for 17.5% of the peak acid output from the canine stomach. The loss of H+ could not be accounted for on the basis of neutralization and probably represented transmucosal insorption. In addition to the neutralization of gastric acid by pancreatic juice and bile, duodenal mucosa thus plays an important role in the maintenance of intraluminal pH. Duodenal mucosal permeability to H+ may be related to the vulnerability of the duodenal mucosa to acid-peptic ulceration.
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Zimmerman B, Chapman ML. Fractionation on lymphocyte surface antigens. I. Rapid method for eliminating labeled lipid from cell surface antigens iodinated by the lactoperoxidase catalysed reaction. J Immunol Methods 1977; 15:183-92. [PMID: 321700 DOI: 10.1016/0022-1759(77)90029-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Fractionation of lactoperoxidase iodinated cell surface material on miniature DEAE-cellulose columns provided a rapid method for separating labeled lipid from cell surface antigens. The procedure also removed poorly solubilized aggregates yielding a labeled preparation which demonstrated stable, reproducible immunoprecipitation results. Using these fractionated antigens components tentatively designated as human 'T' cell specific antigens have been identified.
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Zimmerman B, Chapman ML. Isolation of lymphocyte surface antigens. II. Identification of non-beta 2 -microglobulin-associated human T cell-specific antigen. Eur J Immunol 1976; 6:715-21. [PMID: 65142 DOI: 10.1002/eji.1830061011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Iodinated cell surface components from human thymus lymphocytes labeled by the lactoperoxidase method, were solubilized by papain digestion and then 3 M KCl extraction of the residual cell pellet. Antiserum to human thymus bound three components from this material, mol. wt. approximately equal to 40 000, 20 000 and 12 000 daltons. This antiserum was absorbed with cultured human lymphoblasts (CHL) until it no longer bound CHL antigens or the HLA-beta 2-microglobulin complex. It continued to bind labeled antigens from thymus, peripheral blood lymphocytes and "T" cell-enriched fraction of tonsil lymphocytes. The absorbed antiserum bound a component from papain-solubilized thymus antigens which had an estimated molecular weight of approximately 40 000 daltons and which was not associated with beta 2-microglobulin. This component seemed to be a human T cell-specific antigen.
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Zimmerman B, Chapman ML. Lymphocyte plasma membranes. VI. Surface antigens of lymphocytes in chronic lymphocytic leukemia. J Natl Cancer Inst 1976; 56:725-9. [PMID: 1255795 DOI: 10.1093/jnci/56.4.725] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Surface antigens from lymphocytes of patients with chronic lymphocytic leukemia (CLL) and from normal peripheral blood lymphocytes (PBL) were examined by radioimmunoassay; antisera to lymphocytes (ALS) were used to bind the labeled antigens. Cells from patients with CLL, normal PBL, thymus cells (THY), and cultured human lymphoblasts (CHL) were labeled by lactoperoxidase-catalyzed iodination. ALS (prepared against THY and CHL) were used to bind the labeled antigens solubilized in nonionic detergent. PBL resembled THY, but the CLL resembled CHL. Thus ALS(CHL) had greater potency for CLL antigens than for PBL antigens when compared to ALS(THY). Furthermore, the electrophoretic profiles of the immunoprecipitates from CLL cells revealed a peak of approximately 30,000-35,000 mol wt, which was not found for PBL or THY, but was associated with CHL.
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Rudick J, Gonda M, Rosenberg IR, Chapman ML, Dreiling DA, Janowitz HD. Effects of a beta-adrenergic receptor stimulant (isoproterenol) on pancreatic exocrine secretion. Surgery 1973; 74:338-43. [PMID: 4722700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Chapman ML, Werther JL, Rudick J, Janowitz HD. Pentagastrin infusion-glycine instillation as a measure of acid absorption in the human stomach: comparison to an instilled acid load. Gastroenterology 1972; 63:962-72. [PMID: 4639368] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Rudick J, Werther JL, Chapman ML, Janowitz HD, Kark AE. Hydrogen permeability of canine gastric antral and fundic mucosa following exposure to pancreatic juice. J Surg Res 1972; 13:72-6. [PMID: 5057262 DOI: 10.1016/0022-4804(72)90045-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Rudick J, Werther JL, Chapman ML, Janowitz HD, Kark AE. Effects of physiologic and supramaximal doses of pentagastrin on mucosal blood flow in antral and fundic pouches. Surgery 1972; 71:405-11. [PMID: 5010225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Rudick J, Werther JL, Chapman ML, Dreiling DA, Janowitz HD. Mucosal blood flow in canine antral and fundic pouches. Gastroenterology 1971; 60:263-71. [PMID: 5549266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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Rudick J, Werther JL, Chapman ML, Janowitz HD. Ionic flux across the gastric mucosa: effects of atropine on the permeability of fundus and antrum. Proc Soc Exp Biol Med 1970; 135:605-8. [PMID: 5486691 DOI: 10.3181/00379727-135-35104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Werther JL, Janowitz HD, Dyck WP, Chapman ML, Rudick J. The effect of bile on electrolyte movement across canine gastric antral and fundic mucosa. Gastroenterology 1970; 59:691-7. [PMID: 5475126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
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