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Ballard JE, Pall PS, Vardigan J, Zhao F, Holahan MA, Zhou X, Jochnowitz N, Kraus RL, Klein RM, Henze DA, Houghton AK, Burgey CS, Gibson C, Struyk A. Translational Pharmacokinetic–Pharmacodynamic Modeling of NaV1.7 Inhibitor MK-2075 to Inform Human Efficacious Dose. Front Pharmacol 2021; 12:786078. [PMID: 35002718 PMCID: PMC8740778 DOI: 10.3389/fphar.2021.786078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 11/17/2021] [Indexed: 11/21/2022] Open
Abstract
MK-2075 is a small-molecule selective inhibitor of the NaV1.7 channel investigated for the treatment of postoperative pain. A translational strategy was developed for MK-2075 to quantitatively interrelate drug exposure, target modulation, and the desired pharmacological response in preclinical animal models for the purpose of human translation. Analgesics used as a standard of care in postoperative pain were evaluated in preclinical animal models of nociceptive behavior (mouse tail flick latency and rhesus thermode heat withdrawal) to determine the magnitude of pharmacodynamic (PD) response at plasma concentrations associated with efficacy in the clinic. MK-2075 was evaluated in those same animal models to determine the concentration of MK-2075 required to achieve the desired level of response. Translation of MK-2075 efficacious concentrations in preclinical animal models to a clinical PKPD target in humans was achieved by accounting for species differences in plasma protein binding and in vitro potency against the NaV1.7 channel. Estimates of human pharmacokinetic (PK) parameters were obtained from allometric scaling of a PK model from preclinical species and used to predict the dose required to achieve the clinical exposure. MK-2075 exposure–response in a preclinical target modulation assay (rhesus olfaction) was characterized using a computational PKPD model which included a biophase compartment to account for the observed hysteresis. Translation of this model to humans was accomplished by correcting for species differences in PK NaV1.7 potency, and plasma protein binding while assuming that the kinetics of distribution to the target site is the same between humans and rhesus monkeys. This enabled prediction of the level of target modulation anticipated to be achieved over the dosing interval at the projected clinical efficacious human dose. Integration of these efforts into the early development plan informed clinical study design and decision criteria.
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Affiliation(s)
- Jeanine E. Ballard
- Pharmacokinetics Pharmacodynamics and Drug Metabolism, Merck & Co. Inc., Kenilworth, NJ, United States
- *Correspondence: Jeanine E. Ballard,
| | - Parul S. Pall
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Joshua Vardigan
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Fuqiang Zhao
- Translational Imaging Biomarkers, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Marie A. Holahan
- Translational Imaging Biomarkers, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Xiaoping Zhou
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Nina Jochnowitz
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Richard L. Kraus
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Rebecca M. Klein
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Darrell A. Henze
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Andrea K. Houghton
- Neuroscience Pharmacology, Merck & Co. Inc., Kenilworth, NJ, United States
| | | | - Christopher Gibson
- Pharmacokinetics Pharmacodynamics and Drug Metabolism, Merck & Co. Inc., Kenilworth, NJ, United States
| | - Arie Struyk
- Translational Medicine, Merck & Co. Inc., Kenilworth, NJ, United States
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Adams GL, Pall PS, Grauer SM, Zhou X, Ballard JE, Vavrek M, Kraus RL, Morissette P, Li N, Colarusso S, Bianchi E, Palani A, Klein R, John CT, Wang D, Tudor M, Nolting AF, Biba M, Nowak T, Makarov AA, Reibarkh M, Buevich AV, Zhong W, Regalado EL, Wang X, Gao Q, Shahripour A, Zhu Y, de Simone D, Frattarelli T, Pasquini NM, Magotti P, Iaccarino R, Li Y, Solly K, Lee KJ, Wang W, Chen F, Zeng H, Wang J, Regan H, Amin RP, Regan CP, Burgey CS, Henze DA, Sun C, Tellers DM. Development of ProTx-II Analogues as Highly Selective Peptide Blockers of Na v1.7 for the Treatment of Pain. J Med Chem 2021; 65:485-496. [PMID: 34931831 DOI: 10.1021/acs.jmedchem.1c01570] [Citation(s) in RCA: 5] [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] [Indexed: 01/01/2023]
Abstract
Inhibitor cystine knot peptides, derived from venom, have evolved to block ion channel function but are often toxic when dosed at pharmacologically relevant levels in vivo. The article describes the design of analogues of ProTx-II that safely display systemic in vivo blocking of Nav1.7, resulting in a latency of response to thermal stimuli in rodents. The new designs achieve a better in vivo profile by improving ion channel selectivity and limiting the ability of the peptides to cause mast cell degranulation. The design rationale, structural modeling, in vitro profiles, and rat tail flick outcomes are disclosed and discussed.
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Affiliation(s)
- Gregory L Adams
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Parul S Pall
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Steven M Grauer
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Xiaoping Zhou
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | | | - Marissa Vavrek
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Richard L Kraus
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | | | - Nianyu Li
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Stefania Colarusso
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Elisabetta Bianchi
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Anandan Palani
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Rebecca Klein
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | | | - Deping Wang
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Matthew Tudor
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Andrew F Nolting
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Mirlinda Biba
- Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Timothy Nowak
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | | | | | | | - Wendy Zhong
- Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | | | - Xiao Wang
- Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Qi Gao
- Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | | | - Yuping Zhu
- Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Daniele de Simone
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Tommaso Frattarelli
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Nicolo' Maria Pasquini
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Paola Magotti
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Roberto Iaccarino
- Peptides and Small Molecules R&D Department, IRBM Spa, Via Pontina km 30.600, 00071 Pomezia (RM), Italy
| | - Yuxing Li
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Kelli Solly
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Keun-Joong Lee
- Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Weixun Wang
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Feifei Chen
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Haoyu Zeng
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Jixin Wang
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Hilary Regan
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Rupesh P Amin
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | | | | | - Darrell A Henze
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - Chengzao Sun
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
| | - David M Tellers
- Merck & Co., Inc., West Point, Pennsylvania 19486, United States
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Kraus RL, Zhao F, Pall PS, Zhou D, Vardigan JD, Danziger A, Li Y, Daley C, Ballard JE, Clements MK, Klein RM, Holahan MA, Greshock TJ, Kim RM, Layton ME, Burgey CS, Serra J, Henze DA, Houghton AK. Na v1.7 target modulation and efficacy can be measured in nonhuman primate assays. Sci Transl Med 2021; 13:13/594/eaay1050. [PMID: 34011626 DOI: 10.1126/scitranslmed.aay1050] [Citation(s) in RCA: 5] [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: 05/29/2019] [Revised: 06/03/2020] [Accepted: 02/20/2021] [Indexed: 12/13/2022]
Abstract
Humans with loss-of-function mutations in the Nav1.7 channel gene (SCN9A) show profound insensitivity to pain, whereas those with gain-of-function mutations can have inherited pain syndromes. Therefore, inhibition of the Nav1.7 channel with a small molecule has been considered a promising approach for the treatment of various human pain conditions. To date, clinical studies conducted using selective Nav1.7 inhibitors have not provided analgesic efficacy sufficient to warrant further investment. Clinical studies to date used multiples of in vitro IC50 values derived from electrophysiological studies to calculate anticipated human doses. To increase the chance of clinical success, we developed rhesus macaque models of action potential propagation, nociception, and olfaction, to measure Nav1.7 target modulation in vivo. The potent and selective Nav1.7 inhibitors SSCI-1 and SSCI-2 dose-dependently blocked C-fiber nociceptor conduction in microneurography studies and inhibited withdrawal responses to noxious heat in rhesus monkeys. Pharmacological Nav1.7 inhibition also reduced odor-induced activation of the olfactory bulb (OB), measured by functional magnetic resonance imaging (fMRI) studies consistent with the anosmia reported in Nav1.7 loss-of-function patients. These data demonstrate that it is possible to measure Nav1.7 target modulation in rhesus macaques and determine the plasma concentration required to produce a predetermined level of inhibition. The calculated plasma concentration for preclinical efficacy could be used to guide human efficacious exposure estimates. Given the translatable nature of the assays used, it is anticipated that they can be also used in phase 1 clinical studies to measure target modulation and aid in the interpretation of phase 1 clinical data.
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Affiliation(s)
- Richard L Kraus
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA.
| | - Fuqiang Zhao
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Parul S Pall
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Dan Zhou
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Joshua D Vardigan
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Andrew Danziger
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Yuxing Li
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Christopher Daley
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Jeanine E Ballard
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Michelle K Clements
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Rebecca M Klein
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Marie A Holahan
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Thomas J Greshock
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Ronald M Kim
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Mark E Layton
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Christopher S Burgey
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Jordi Serra
- Department of Clinical Neurophysiology, Ruskin Wing, King's College Hospital, Denmark Hill, London SE5 9RS, UK
| | - Darrell A Henze
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
| | - Andrea K Houghton
- Merck & Co. Inc., WP-14, 770 Sumneytown Pike, P.O. Box 4, West Point, PA 19486, USA
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Vardigan JD, Houghton AK, Lange HS, Adarayan ED, Pall PS, Ballard JE, Henze DA, Uslaner JM. Pharmacological validation of a novel nonhuman primate measure of thermal responsivity with utility for predicting analgesic effects. J Pain Res 2018; 11:735-741. [PMID: 29692626 PMCID: PMC5903490 DOI: 10.2147/jpr.s152879] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Introduction The development of novel analgesics to treat acute or chronic pain has been a challenge due to a lack of translatable measurements. Preclinical end points with improved translatability are necessary to more accurately inform clinical testing paradigms, which may help guide selection of viable drug candidates. Methods In this study, a nonhuman primate biomarker which is sensitive to standard analgesics at clinically relevant plasma concentrations, can differentiate analgesia from sedation and utilizes a protocol very similar to that which can be employed in human clinical studies is described. Specifically, acute heat stimuli were delivered to the volar forearm using a contact heat thermode in the same manner as the clinical setting. Results Clinically efficacious exposures of morphine, fentanyl, and tramadol produced robust analgesic effects, whereas doses of diazepam that produce sedation had no effect. Conclusion We propose that this assay has predictive utility that can help improve the probability of success for developing novel analgesics.
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Affiliation(s)
| | | | | | | | - Parul S Pall
- Merck Research Laboratories, West Point, PA, USA
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Weisshaar CL, Kras JV, Pall PS, Kartha S, Winkelstein BA. Ablation of IB4 non-peptidergic afferents in the rat facet joint prevents injury-induced pain and thalamic hyperexcitability via supraspinal glutamate transporters. Neurosci Lett 2017; 655:82-89. [PMID: 28689926 DOI: 10.1016/j.neulet.2017.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 05/28/2017] [Revised: 07/04/2017] [Accepted: 07/05/2017] [Indexed: 12/12/2022]
Abstract
The facet joint is a common source of neck pain, particularly after excessive stretch of its capsular ligament. Peptidergic afferents have been shown to have an important role in the development and maintenance of mechanical hyperalgesia, dysregulated nociceptive signaling, and spinal hyperexcitability that develop after mechanical injury to the facet joint. However, the role of non-peptidergic isolectin-B4 (IB4) cells in mediating joint pain is unknown. Isolectin-B4 saporin (IB4-SAP) was injected into the facet joint to ablate non-peptidergic cells, and the facet joint later underwent a ligament stretch known to induce pain. Behavioral sensitivity, thalamic glutamate transporter expression, and thalamic hyperexcitability were evaluated up to and at day 7. Administering IB4-SAP prior to a painful injury prevented the development of mechanical hyperalgesia that is typically present. Intra-articular IB4-SAP also prevented the upregulation of the glutamate transporters GLT-1 and EAAC1 in the ventral posterolateral nucleus of the thalamus and reduced thalamic neuronal hyperexcitability at day 7. These findings suggest that a painful facet injury induces changes extending to supraspinal structures and that IB4-positive afferents in the facet joint may be critical for the development and maintenance of sensitization in the thalamus after a painful facet joint injury.
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Affiliation(s)
- Christine L Weisshaar
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St Philadelphia, PA 19104, USA
| | - Jeffrey V Kras
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St Philadelphia, PA 19104, USA
| | - Parul S Pall
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St Philadelphia, PA 19104, USA
| | - Sonia Kartha
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St Philadelphia, PA 19104, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, 240 Skirkanich Hall, 210 S. 33rd St Philadelphia, PA 19104, USA; Department of Neurosurgery, University of Pennsylvania, 105 Hayden Hall, 3320 Smith Walk, Philadelphia, PA 19104, USA.
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Kras JV, Weisshaar CL, Pall PS, Winkelstein BA. Pain from intra-articular NGF or joint injury in the rat requires contributions from peptidergic joint afferents. Neurosci Lett 2015; 604:193-8. [PMID: 26240991 DOI: 10.1016/j.neulet.2015.07.043] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [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: 06/20/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 02/06/2023]
Abstract
Non-physiological stretch of the cervical facet joint's capsular ligament induces persistent behavioral hypersensitivity and spinal neuronal hyperexcitability via an intra-articular NGF-dependent mechanism. Although that ligament is innervated by nociceptors, it is unknown if a subpopulation is exclusively responsible for the behavioral and spinal neuronal responses to intra-articular NGF and/or facet joint injury. This study ablated joint afferents using the neurotoxin saporin targeted to neurons involved in either peptidergic ([Sar(9),Met (O2)(11)]-substance P-saporin (SSP-Sap)) or non-peptidergic (isolectin B4-saporin (IB4-Sap)) signaling to investigate the contributions of those neuronal populations to facet-mediated pain. SSP-Sap, but not IB4-Sap, injected into the bilateral C6/C7 facet joints 14 days prior to an intra- articular NGF injection prevents NGF-induced mechanical and thermal hypersensitivity in the forepaws. Similarly, only SSP- Sap prevents the increase in mechanical forepaw stimulation- induced firing of spinal neurons after intra-articular NGF. In addition, intra-articular SSP-Sap prevents both behavioral hypersensitivity and upregulation of NGF in the dorsal root ganglion after a facet joint distraction that normally induces pain. These findings collectively suggest that disruption of peptidergic signaling within the joint may be a potential treatment for facet pain, as well as other painful joint conditions associated with elevated NGF, such as osteoarthritis.
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Affiliation(s)
- Jeffrey V Kras
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine L Weisshaar
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Parul S Pall
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Beth A Winkelstein
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Neurosurgery, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Pall PS, Hurwitz OE, King BA, LaMotte RH. Psychophysical measurements of itch and nociceptive sensations in an experimental model of allergic contact dermatitis. J Pain 2015; 16:741-9. [PMID: 26002605 DOI: 10.1016/j.jpain.2015.04.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Revised: 04/25/2015] [Accepted: 04/28/2015] [Indexed: 11/25/2022]
Abstract
UNLABELLED Allergic contact dermatitis (ACD) is a common condition that can significantly affect the quality of life. Contact with allergens results in delayed hypersensitivity reactions involving T lymphocytes, with associated skin inflammation and spontaneous itch and nociceptive sensations. However, psychophysical studies of these sensations are lacking. In the present study, we sensitized 8 healthy volunteers to squaric acid dibutyl ester (SADBE). Two weeks later, 1 volar forearm was challenged with SADBE, and the other with acetone vehicle control. Subsequently, participants rated the maximal perceived intensity of spontaneous itch, pricking/stinging, and burning every 6 to 12 hours for 1 week, using the generalized Labeled Magnitude Scale. In the laboratory, they judged stimulus-evoked sensations within and outside the chemically treated area. The SADBE- but not the acetone-treated skin resulted in 1) localized inflammation, with spontaneous itch and nociceptive sensations peaking at 24 to 48 hours after challenge, 2) alloknesis, hyperknesis, and hyperalgesia to mechanical stimuli that were reduced or eliminated by anesthetic cooling of the SADBE-treated area and restored on rewarming, suggesting that sensations and dysesthesias are dependent on ongoing peripheral neural activity, and 3) enhanced itch to intradermal injection of histamine, BAM8-22, or β-alanine. This experimental model of T-cell-mediated inflammation may prove useful in evaluating potential treatments of itch from ACD. PERSPECTIVE In a model of allergic contact dermatitis, experimentally applied in humans, psychophysical measurements were obtained of persistent, spontaneous itch and enhanced stimulus-evoked itch and pain sensations. These sensory measurements will be useful in the identification of the neural mechanisms underlying inflammatory itch and pain.
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Affiliation(s)
- Parul S Pall
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut
| | - Olivia E Hurwitz
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut
| | - Brett A King
- Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut
| | - Robert H LaMotte
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut.
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