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Trueblood CT, Singh A, Cusimano MA, Hou S. Autonomic Dysreflexia in Spinal Cord Injury: Mechanisms and Prospective Therapeutic Targets. Neuroscientist 2023:10738584231217455. [PMID: 38084412 PMCID: PMC11166887 DOI: 10.1177/10738584231217455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2024]
Abstract
High-level spinal cord injury (SCI) often results in cardiovascular dysfunction, especially the development of autonomic dysreflexia. This disorder, characterized as an episode of hypertension accompanied by bradycardia in response to visceral or somatic stimuli, causes substantial discomfort and potentially life-threatening symptoms. The neural mechanisms underlying this dysautonomia include a loss of supraspinal control to spinal sympathetic neurons, maladaptive plasticity of sensory inputs and propriospinal interneurons, and excessive discharge of sympathetic preganglionic neurons. While neural control of cardiovascular function is largely disrupted after SCI, the renin-angiotensin system (RAS), which mediates blood pressure through hormonal mechanisms, is up-regulated after injury. Whether the RAS engages in autonomic dysreflexia, however, is still controversial. Regarding therapeutics, transplantation of embryonic presympathetic neurons, collected from the brainstem or more specific raphe regions, into the injured spinal cord may reestablish supraspinal regulation of sympathetic activity for cardiovascular improvement. This treatment reduces the occurrence of spontaneous autonomic dysreflexia and the severity of artificially triggered dysreflexic responses in rodent SCI models. Though transplanting early-stage neurons improves neural regulation of blood pressure, hormonal regulation remains high and baroreflex dysfunction persists. Therefore, cell transplantation combined with selected RAS inhibition may enhance neuroendocrine homeostasis for cardiovascular recovery after SCI.
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Affiliation(s)
- Cameron T. Trueblood
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Anurag Singh
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Marissa A. Cusimano
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
| | - Shaoping Hou
- Marion Murray Spinal Cord Research Center, Department of Neurobiology and Anatomy, College of Medicine, Drexel University, Philadelphia, PA, USA
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2
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Wecht JM, Weir JP, Katzelnick CG, Dyson-Hudson TA, Bauman WA, Kirshblum SC. Clinical trial of home blood pressure monitoring following midodrine administration in hypotensive individuals with spinal cord injury. J Spinal Cord Med 2023; 46:531-539. [PMID: 36972219 DOI: 10.1080/10790268.2021.1977904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Individuals with spinal cord injury (SCI) above thoracic level-6 (T6) experience impaired descending cortical control of the autonomic nervous system which predisposes them to blood pressure (BP) instability, including includes hypotension, orthostatic hypotension (OH), and autonomic dysreflexia (AD). However, many individuals do not report symptoms of these BP disorders, and because there are few treatment options that have been proven safe and effective for use in the SCI population, most individuals remain untreated. OBJECTIVE The primary aim of this investigation was to determine the effects of midodrine (10 mg) prescribed TID or BID in the home environment, compared to placebo, on 30-day BP, study withdrawals, and symptom reporting associated with OH and AD in hypotensive individuals with SCI. DESIGN/METHODS Participants were randomly assigned to received midodrine/placebo or placebo/midodrine, with a 2-weeks washout period in between, and both the participants and investigators were blinded to randomization order. Study medication was taken 2 or 3 times/day, depending on their sleep/wake schedule, BP, and any related symptoms were recorded before and 1 h after each dosage and periodically throughout the day. RESULTS Nineteen individuals with SCI were recruited; however, 9 withdrew prior to completion of the full protocol. A total of 1892 BP recordings (75 ± 48 recordings/participant/30-day period) were collected in the 19 participants over the two 30-day monitoring periods. Average 30-day systolic BP was significantly increased with midodrine compared to placebo (114 ± 14 vs. 96 ± 11 mmHg, respectively; P = 0.004), and midodrine significantly reduced the number of hypotensive BP recordings compared to placebo (38.7 ± 41.9 vs. 73.3 ± 40.6, respectively; P = 0.01). However, compared to placebo, midodrine increased fluctuations in BP, did not improve symptoms of OH, but did significantly worsen the intensity of symptoms associated with AD (P = 0.03). CONCLUSION Midodrine (10 mg) administered in the home environment effectively increases BP and reduces the incidence of hypotension; however these beneficial effects come at the expense of worsened BP instability and AD symptom intensity.
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Affiliation(s)
- Jill M Wecht
- James J Peters VA Medical Center, Bronx, NY, USA
- Departments of Medicine, the Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Rehabilitation Medicine and Human Performance at the Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Joseph P Weir
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, KS, USA
| | - Caitlyn G Katzelnick
- James J Peters VA Medical Center, Bronx, NY, USA
- Kessler Foundation, West Orange, NJ, USA
| | - Trevor A Dyson-Hudson
- Kessler Foundation, West Orange, NJ, USA
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ, USA
| | - William A Bauman
- James J Peters VA Medical Center, Bronx, NY, USA
- Departments of Medicine, the Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Rehabilitation Medicine and Human Performance at the Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Steven C Kirshblum
- Kessler Foundation, West Orange, NJ, USA
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, NJ, USA
- Kessler Institute for Rehabilitation, West Orange, NJ, USA
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3
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Hayes BD, Fossey MPM, Poormasjedi-Meibod MS, Erskine E, Soriano JE, Scott B, Rosentreter R, Granville DJ, Phillips AA, West CR. Experimental high thoracic spinal cord injury impairs the cardiac and cerebrovascular response to orthostatic challenge in rats. Am J Physiol Heart Circ Physiol 2021; 321:H716-H727. [PMID: 34448635 DOI: 10.1152/ajpheart.00239.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 08/24/2021] [Indexed: 11/22/2022]
Abstract
Spinal cord injury (SCI) impairs the cardiovascular responses to postural challenge, leading to the development of orthostatic hypotension (OH). Here, we apply lower body negative pressure (LBNP) to rodents with high-level SCI to demonstrate the usefulness of LBNP as a model for experimental OH studies, and to explore the effect of simulated OH on cardiovascular and cerebrovascular function following SCI. Male Wistar rats (n = 34) were subjected to a sham or T3-SCI surgery and survived into the chronic period postinjury (i.e., 8 wk). Cardiac function was tracked via ultrasound pre- to post-SCI to demonstrate the clinical utility of our model. At study termination, we conducted left-ventricular (LV) catheterization and insonated the middle cerebral artery to investigate the hemodynamic, cardiac, and cerebrovascular response to a mild dose of LBNP that is sufficient to mimic clinically defined OH in rats with T3-SCI but not sham animals. In response to mimicked OH, there was a greater decline in stroke volume, cardiac output, maximal LV pressure, and blood pressure in SCI compared with sham (P < 0.034), whereas heart rate was increased in sham but decreased in SCI (P < 0.029). SCI animals also had an exaggerated reduction in peak, minimum and mean middle cerebral artery flow, for a given change in blood pressure, in response to LBNP (P < 0.033), implying impaired dynamic cerebral autoregulation. Using a preclinical SCI model of OH, we demonstrate that complete high thoracic SCI impairs the cardiac response to OH and disrupts dynamic cerebral autoregulation.NEW & NOTEWORTHY This is the first use of LBNP to interrogate the cardiac and cerebrovascular responses to simulated OH in a preclinical study of SCI. Here, we demonstrate the utility of our simulated OH model and use it to demonstrate that SCI impairs the cardiac response to simulated OH and disrupts dynamic cerebrovascular autoregulation.
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Affiliation(s)
- Brian D Hayes
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- School of Kinesiology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mary Pauline Mona Fossey
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Experimental Medicine, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Erin Erskine
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jan Elaine Soriano
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Berkeley Scott
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Ryan Rosentreter
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - David J Granville
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Cardiac Sciences, Clinical Neurosciences, Libin Cardiovascular Institute, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Christopher R West
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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4
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Katzelnick CG, Weir JP, Pinto Zipp G, LaFountaine MF, Bauman WA, Dyson-Hudson TA, Wecht JM. Increased pulse wave velocity in persons with spinal cord injury: the effect of the renin-angiotensin-aldosterone system. Am J Physiol Heart Circ Physiol 2020; 320:H272-H280. [PMID: 33095646 DOI: 10.1152/ajpheart.00544.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Increased pulse wave velocity (PWV), a marker of cardiovascular disease (CVD), has been reported in otherwise healthy individuals with spinal cord injury (SCI) compared with age-matched uninjured controls. Due to decentralized descending sympathetic vascular control, individuals with injuries above T6 are prone to orthostatic hypotension and, as a result, depend on the renin-angiotensin-aldosterone system (RAAS) to maintain orthostatic blood pressure (BP). The purpose of this study was to determine resting PWV, a noninvasive surrogate of central arterial stiffness, in individuals with cervical (C4-T1; n = 11) and thoracic (T6-T12; n = 11) SCI, compared with age-matched controls (controls; n = 11). Next, our aim was to describe group differences in BP, plasma norepinephrine (NE), and renin response to head-up tilt (HUT). Finally, we sought to determine the relationship between PWV and the orthostatic change in BP, NE, and the plasma renin during HUT among the groups. PWV was significantly increased in both cervical (8.81 ± 1.91 m/s) and thoracic (7.36 ± 1.58 m/s) SCI compared with the controls (5.53 ± 0.95 m/s; P < 0.05). The change from supine to 60° HUT in BP and NE was significantly reduced and change in plasma renin was significantly increased in the cervical group compared with the thoracic and control groups. Group affiliation and change in plasma renin were significant predictors of PWV (R2 = 0.63, P = 0.001). These data suggest that dependency on the RAAS for orthostatic BP maintenance may be associated with increased PWV and risk of CVD in the SCI population.NEW & NOTEWORTHY Our novel findings suggest that increased arterial stiffness in individuals with SCI may be due to greater dependency on the RAAS to maintain hemodynamic stability during an orthostatic challenge. Asymptomatic orthostatic hypotension can occur in persons with SCI during transition from the supine to the seated position and during other upright activities of daily living; however, it is seldom addressed by clinicians.
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Affiliation(s)
- Caitlyn G Katzelnick
- James J Peters Veterans Affairs Medical Center, Bronx, New York.,Kessler Foundation, West Orange, New Jersey.,Department of Interprofessional Health Sciences and Health Administration, School of Health and Medical Sciences, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey
| | - Joseph P Weir
- Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas
| | - Genevieve Pinto Zipp
- Department of Interprofessional Health Sciences and Health Administration, School of Health and Medical Sciences, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey
| | - Michael F LaFountaine
- James J Peters Veterans Affairs Medical Center, Bronx, New York.,Department of Physical Therapy, School of Health and Medical Sciences, Seton Hall University, South Orange, New Jersey.,Department of Medical Sciences and Neurology, Hackensack Meridian School of Medicine at Seton Hall University, Nutley, New Jersey.,Icahn School of Medicine at Mount Sinai, New York City, New York
| | - William A Bauman
- James J Peters Veterans Affairs Medical Center, Bronx, New York.,Icahn School of Medicine at Mount Sinai, New York City, New York
| | - Trevor A Dyson-Hudson
- Kessler Foundation, West Orange, New Jersey.,Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Jill M Wecht
- James J Peters Veterans Affairs Medical Center, Bronx, New York.,Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, New Jersey
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5
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Cardiovascular Autonomic Dysfunction in Spinal Cord Injury: Epidemiology, Diagnosis, and Management. Semin Neurol 2020; 40:550-559. [PMID: 32906175 DOI: 10.1055/s-0040-1713885] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Spinal cord injury (SCI) disrupts autonomic circuits and impairs synchronistic functioning of the autonomic nervous system, leading to inadequate cardiovascular regulation. Individuals with SCI, particularly at or above the sixth thoracic vertebral level (T6), often have impaired regulation of sympathetic vasoconstriction of the peripheral vasculature and the splanchnic circulation, and diminished control of heart rate and cardiac output. In addition, impaired descending sympathetic control results in changes in circulating levels of plasma catecholamines, which can have a profound effect on cardiovascular function. Although individuals with lesions below T6 often have normal resting blood pressures, there is evidence of increases in resting heart rate and inadequate cardiovascular response to autonomic provocations such as the head-up tilt and cold face tests. This manuscript reviews the prevalence of cardiovascular disorders given the level, duration and severity of SCI, the clinical presentation, diagnostic workup, short- and long-term consequences, and empirical evidence supporting management strategies to treat cardiovascular dysfunction following a SCI.
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6
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Sarafis ZK, Monga AK, Phillips AA, Krassioukov AV. Is Technology for Orthostatic Hypotension Ready for Primetime? PM R 2019; 10:S249-S263. [PMID: 30269810 DOI: 10.1016/j.pmrj.2018.04.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/04/2018] [Accepted: 04/12/2018] [Indexed: 01/29/2023]
Abstract
Spinal cord injury (SCI) often results in the devastating loss of motor, sensory, and autonomic function. After SCI, the interruption of descending sympathoexcitatory pathways disrupts supraspinal control of blood pressure (BP). A common clinical consequence of cardiovascular dysfunction after SCI is orthostatic hypotension (OH), a debilitating condition characterized by rapid profound decreases in BP when assuming an upright posture. OH can result in a diverse array of insidious and pernicious health consequences. Acute effects of OH include decreased cardiac filling, cerebral hypoperfusion, and associated presyncopal symptoms such as lightheadedness and dizziness. Over the long term, repetitive exposure to OH is associated with a drastically increased prevalence of heart attack and stroke, which are leading causes of death in those with SCI. Current recommendations for managing BP after SCI primarily include pharmacologic interventions with prolonged time to effect. Because most episodes of OH occur in less than 3 minutes, this delay in action often renders most pharmacologic interventions ineffective. New innovative technologies such as epidural and transcutaneous spinal cord stimulation are being explored to solve this problem. It might be possible to electrically stimulate sympathetic circuitry caudal to the injury and elicit rapid modulation of BP to manage OH. This review describes autonomic control of the cardiovascular system before injury, resulting cardiovascular consequences after SCI such as OH, and the clinical assessment tools for evaluating autonomic dysfunction after SCI. In addition, current approaches for clinically managing OH are outlined, and new promising interventions are described for managing this condition.
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Affiliation(s)
- Zoe K Sarafis
- ICORD-BSCC, University of British Columbia, Vancouver, BC, Canada(∗)
| | - Aaron K Monga
- ICORD-BSCC, University of British Columbia, Vancouver, BC, Canada(†)
| | - Aaron A Phillips
- Departments of Physiology and Pharmacology, Clinical Neurosciences, Cardiac Sciences, Libin Cardiovascular Institute of Alberta, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada(‡)
| | - Andrei V Krassioukov
- ICORD-BSCC; Experimental Medicine Program; Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia; GF Strong Rehabilitation Center, Vancouver Coastal Health; 818 West 10th Avenue, Vancouver, BC, Canada, V5Z1M9(§).
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7
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Stykel MG, Humphries K, Kirby MP, Czaniecki C, Wang T, Ryan T, Bamm V, Ryan SD. Nitration of microtubules blocks axonal mitochondrial transport in a human pluripotent stem cell model of Parkinson's disease. FASEB J 2018; 32:5350-5364. [PMID: 29688812 DOI: 10.1096/fj.201700759rr] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Neuronal loss in Parkinson's disease (PD) is associated with aberrant mitochondrial function in dopaminergic (DA) neurons of the substantia nigra pars compacta. An association has been reported between PD onset and exposure to mitochondrial toxins, including the agrochemicals paraquat (PQ), maneb (MB), and rotenone (Rot). Here, with the use of a patient-derived stem cell model of PD, allowing comparison of DA neurons harboring a mutation in the α-synuclein (α-syn) gene ( SNCA-A53T) against isogenic, mutation-corrected controls, we describe a novel mechanism whereby NO, generated from SNCA-A53T mutant neurons exposed to Rot or PQ/MB, inhibits anterograde mitochondrial transport through nitration of α-tubulin (α-Tub). Nitration of α-Tub inhibited the association of both α-syn and the mitochondrial motor protein kinesin 5B with the microtubules, arresting anterograde transport. This was, in part, a result of nitration of α-Tub in the C-terminal domain. These effects were rescued by inhibiting NO synthesis with the NOS inhibitor Nω-nitro-L-arginine methyl ester. Collectively, our results are the first to demonstrate a gene by environment interaction in PD, whereby agrochemical exposure selectively triggers a deficit in mitochondrial transport by nitrating the microtubules in neurons harboring the SNCA-A53T mutation.-Stykel, M. G., Humphries, K., Kirby, M. P., Czaniecki, C., Wang, T., Ryan, T., Bamm, V., Ryan, S. D. Nitration of microtubules blocks axonal mitochondrial transport in a human pluripotent stem cell model of Parkinson's disease.
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Affiliation(s)
- Morgan G Stykel
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Kayla Humphries
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Mathew P Kirby
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Chris Czaniecki
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Tinya Wang
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Tammy Ryan
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Vladimir Bamm
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Scott D Ryan
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.,Neurodegenerative Disease Center, Scintillon Institute, San Diego, California, USA
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8
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Wecht JM, Bauman WA. Implication of altered autonomic control for orthostatic tolerance in SCI. Auton Neurosci 2018; 209:51-58. [DOI: 10.1016/j.autneu.2017.04.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 03/16/2017] [Accepted: 04/25/2017] [Indexed: 12/22/2022]
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9
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Katzelnick CG, Weir JP, Chiaravalloti ND, Wylie GR, Dyson-Hudson TA, Bauman WA, Wecht JM. Impact of Blood Pressure, Lesion Level, and Physical Activity on Aortic Augmentation Index in Persons with Spinal Cord Injury. J Neurotrauma 2017; 34:3407-3415. [DOI: 10.1089/neu.2017.5065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Caitlyn G. Katzelnick
- VA RR&D National Center for Medication Consequences of Spinal Cord Injury, James J Peters VA Medical Center, Bronx, New York
- Department of Research, Kessler Foundation, West Orange, New Jersey
| | - Joseph P. Weir
- Department of Health, Sport, and Exercise Science, University of Kansas, Lawrence, Kansas
| | - Nancy D. Chiaravalloti
- Department of Research, Kessler Foundation, West Orange, New Jersey
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, New Jersey
| | - Glenn R. Wylie
- Department of Research, Kessler Foundation, West Orange, New Jersey
- The War Related Illness and Injury Study Center, VA New Jersey Health Care System, East Orange, New Jersey
| | - Trevor A. Dyson-Hudson
- Department of Research, Kessler Foundation, West Orange, New Jersey
- Department of Physical Medicine and Rehabilitation, Rutgers New Jersey Medical School, Newark, New Jersey
| | - William A. Bauman
- VA RR&D National Center for Medication Consequences of Spinal Cord Injury, James J Peters VA Medical Center, Bronx, New York
- Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York
| | - Jill M. Wecht
- VA RR&D National Center for Medication Consequences of Spinal Cord Injury, James J Peters VA Medical Center, Bronx, New York
- Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York
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10
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Increasing the Fungicidal Action of Amphotericin B by Inhibiting the Nitric Oxide-Dependent Tolerance Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2017; 2017:4064628. [PMID: 29129987 PMCID: PMC5654257 DOI: 10.1155/2017/4064628] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/02/2017] [Indexed: 11/21/2022]
Abstract
Amphotericin B (AmB) induces oxidative and nitrosative stresses, characterized by production of reactive oxygen and nitrogen species, in fungi. Yet, how these toxic species contribute to AmB-induced fungal cell death is unclear. We investigated the role of superoxide and nitric oxide radicals in AmB's fungicidal activity in Saccharomyces cerevisiae, using a digital microfluidic platform, which enabled monitoring individual cells at a spatiotemporal resolution, and plating assays. The nitric oxide synthase inhibitor L-NAME was used to interfere with nitric oxide radical production. L-NAME increased and accelerated AmB-induced accumulation of superoxide radicals, membrane permeabilization, and loss of proliferative capacity in S. cerevisiae. In contrast, the nitric oxide donor S-nitrosoglutathione inhibited AmB's action. Hence, superoxide radicals were important for AmB's fungicidal action, whereas nitric oxide radicals mediated tolerance towards AmB. Finally, also the human pathogens Candida albicans and Candida glabrata were more susceptible to AmB in the presence of L-NAME, pointing to the potential of AmB-L-NAME combination therapy to treat fungal infections.
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11
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Bauman WA, Wecht JM, Biering-Sørensen F. International spinal cord injury endocrine and metabolic extended data set. Spinal Cord 2017; 55:466-477. [DOI: 10.1038/sc.2016.164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 10/21/2016] [Indexed: 01/27/2023]
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12
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Lee AHX, Phillips AA, Krassioukov AV. Increased Central Arterial Stiffness after Spinal Cord Injury: Contributing Factors, Implications, and Possible Interventions. J Neurotrauma 2017; 34:1129-1140. [DOI: 10.1089/neu.2016.4694] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Amanda H. X. Lee
- International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada
- Experimental Medicine Program, Faculty of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
| | - Aaron A. Phillips
- International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada
- Experimental Medicine Program, Faculty of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physical Therapy, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
| | - Andrei V. Krassioukov
- International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada
- Experimental Medicine Program, Faculty of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Physical Therapy, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Medicine, Division of Physical Medicine and Rehabilitation, University of British Columbia, Vancouver, British Columbia, Canada
- GF Strong Rehabilitation Center, Vancouver Coastal Health, Vancouver, British Columbia, Canada
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13
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Wecht JM, Weir JP, Radulovic M, Bauman WA. Effects of midodrine and L-NAME on systemic and cerebral hemodynamics during cognitive activation in spinal cord injury and intact controls. Physiol Rep 2016; 4:4/3/e12683. [PMID: 26869679 PMCID: PMC4758920 DOI: 10.14814/phy2.12683] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
We previously showed that increases in mean arterial pressure (MAP) following administration of midodrine hydrochloride (MH) and nitro‐L‐arginine methyl ester (L‐NAME) resulted in increased mean cerebral blood flow velocity (MFV) during head‐up tilt in hypotensive individuals with spinal cord injury (SCI) and question if this same association was evident during cognitive activation. Herein, we report MAP and MFV during two serial subtraction tasks (SSt) given before (predrug) and after (postdrug) administration of MH; (10 mg), L‐NAME (1 mg/kg) or no drug (ND) in 15 subjects with SCI compared to nine able‐bodied (AB) controls. Three‐way factorial analysis of variance (ANOVA) models were used to determine significant main and interaction effects for group (SCI, AB), visit (MH, L‐NAME, ND), and time (predrug, postdrug) for MAP and MFV during the two SSt. The three‐way interaction was significant for MAP (F = 4.262; P = 0.020); both MH (30 ± 26 mmHg; P < 0.05) and L‐NAME (27 ± 22 mmHg; P < 0.01) significantly increased MAP in the SCI group, but not in the AB group. There was a significant visit by time interaction for MFV suggesting an increase from predrug to postdrug following L‐NAME (6 ± 8 cm/sec; P < 0.05) and MH (4 ± 7 cm/sec; P < 0.05), regardless of study group, with little change following ND (3 ± 3 cm/sec). The relationship between change in MAP and MFV was significant in the SCI group following administration of MH (r2 = 0.38; P < 0.05) and L‐NAME (r2 = 0.32; P < 0.05). These antihypotensive agents, at the doses tested, raised MAP, which was associated with an increase MFV during cognitive activation in hypotensive subjects with SCI.
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Affiliation(s)
- Jill M Wecht
- VA RR&D National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VAMC, Bronx, New York The Medical Service, James J. Peters VAMC, Bronx New York Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York Department of Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York
| | - Joseph P Weir
- Department of Health, Sport and Exercise Sciences, The University of Kansas, Lawrence, Kansas
| | - Miroslav Radulovic
- VA RR&D National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VAMC, Bronx, New York The Medical Service, James J. Peters VAMC, Bronx New York Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York Department of Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York
| | - William A Bauman
- VA RR&D National Center for the Medical Consequences of Spinal Cord Injury, James J. Peters VAMC, Bronx, New York The Medical Service, James J. Peters VAMC, Bronx New York Department of Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York Department of Rehabilitation Medicine, The Icahn School of Medicine at Mount Sinai, New York, New York
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Wecht JM, La Fountaine MF, Handrakis JP, West CR, Phillips A, Ditor DS, Sharif H, Bauman WA, Krassioukov AV. Autonomic Nervous System Dysfunction Following Spinal Cord Injury: Cardiovascular, Cerebrovascular, and Thermoregulatory Effects. CURRENT PHYSICAL MEDICINE AND REHABILITATION REPORTS 2015. [DOI: 10.1007/s40141-015-0093-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Wecht JM, Cirnigliaro CM, Azarelo F, Bauman WA, Kirshblum SC. Orthostatic responses to anticholinesterase inhibition in spinal cord injury. Clin Auton Res 2015; 25:179-87. [PMID: 25916633 DOI: 10.1007/s10286-015-0272-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 11/02/2014] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Acetylcholine (Ach) is the pre-synaptic neurotransmitter of the sympathetic nervous system. Increased pre-synaptic Ach may augment post-synaptic release of norepinephrine, thereby increasing systemic blood pressure (BP). OBJECTIVES The primary objective of this investigation was to determine the hemodynamic effect of pyridostigmine bromide (PYRIDO: 60 mg), an Ach inhibitor (AchI), compared to no-drug (NO-D) during head-up tilt (HUT) in individuals with spinal cord injury (SCI). Secondarily, we aimed to determine the effects of PYRIDO compared to NO-D on symptoms of orthostatic intolerance (OI) and adverse event reporting (AE). METHODS Ten individuals with SCI (C4-C7) were studied on two occasions: visit (1) NO-D and visit (2) PYRIDO. On each visit subjects underwent a progressive HUT maneuver to 15°, 25°, 35° for 5 min at each angle and 45 min at 45°. Supine and orthostatic heart rate (HR), systolic and diastolic BP (SBP and DBP), as well as monitored and symptoms of OI and AE were monitored and recorded. RESULTS Supine hemodynamics did not differ between the trials. The significant fall in SBP during the NO-D trial was diminished with PYRIDO, and five subjects had an increased DBP during HUT with PYRIDO compared to the NO-D trial. Individuals that responded to PYRIDO with an increase in orthostatic BP had significantly lower resting HR than non-responders (p < 0.01), which suggests increased levels of pre-synaptic Ach. Subjective symptoms of OI and AE reporting did not differ between the two trials. CONCLUSIONS These preliminary data suggest that PYRIDO is safe and may be effective at ameliorating the orthostatic fall in BP in select individuals with SCI.
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Affiliation(s)
- Jill M Wecht
- The National Center of Excellence, James J. Peters VAMC, Bronx, NY, USA,
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16
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Phillips AA, Krassioukov AV, Ainslie PN, Warburton DER. Perturbed and spontaneous regional cerebral blood flow responses to changes in blood pressure after high-level spinal cord injury: the effect of midodrine. J Appl Physiol (1985) 2014; 116:645-53. [PMID: 24436297 DOI: 10.1152/japplphysiol.01090.2013] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Individuals with spinal cord injury (SCI) above the T6 spinal segment suffer from orthostatic intolerance. How cerebral blood flow (CBF) responds to orthostatic challenges in SCI is poorly understood. Furthermore, it is unclear how interventions meant to improve orthostatic tolerance in SCI influence CBF. This study aimed to examine 1) the acute regional CBF responses to rapid changes in blood pressure (BP) during orthostatic stress in individuals with SCI and able-bodied (AB) individuals; and 2) the effect of midodrine (alpha1-agonist) on orthostatic tolerance and CBF regulation in SCI. Ten individuals with SCI >T6, and 10 age- and sex-matched AB controls had beat-by-beat BP and middle and posterior cerebral artery blood velocity (MCAv, PCAv, respectively) recorded during a progressive tilt-test to quantify the acute CBF response and orthostatic tolerance. Dynamic MCAv and PCAv to BP relationships were evaluated continuously in the time domain and frequency domain (via transfer function analysis). The SCI group was tested again after administration of 10 mg midodrine to elevate BP. Coherence (i.e., linearity) was elevated in SCI between BP-MCAv and BP-PCAv by 35% and 22%, respectively, compared with AB, whereas SCI BP-PCAv gain (i.e., magnitudinal relationship) was reduced 30% compared with AB (all P < 0.05). The acute (i.e., 0-30 s after tilt) MCAv and PCAv responses were similar between groups. In individuals with SCI, midodrine led to improved PCAv responses 30-60 s following tilt (10 ± 3% vs. 4 ± 2% decline; P < 0.05), and a 59% improvement in orthostatic tolerance (P < 0.01). The vertebrobasilar region may be particularly susceptible to hypoperfusion in SCI, leading to increased orthostatic intolerance.
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Affiliation(s)
- Aaron A Phillips
- Cardiovascular Physiology and Rehabilitation Laboratory, Physical Activity Promotion and Chronic Disease Prevention Unit, University of British Columbia, Vancouver, British Columbia, Canada
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Perez-Lloret S, Rey MV, Pavy-Le Traon A, Rascol O. Orthostatic hypotension in Parkinson’s disease. Neurodegener Dis Manag 2013. [DOI: 10.2217/nmt.13.30] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
SUMMARY Orthostatic hypotension (OH) is a frequent non-motor symptom in Parkinson’s disease (PD), affecting between 22.9 and 38.4% of patients. In PD, OH is related to an increased risk of falls, and possibly to cognitive dysfunction and increased mortality. These data emphasize the importance of its prompt recognition and treatment. OH is related to pre- and post-ganglionic adrenergic denervation, but other factors, such as drugs, heat, meals or alcohol intake, might also induce or aggravate it. Evidence about the efficacy and safety of pharmacological or nonpharmacological strategies for OH treatment in PD is weak. Nonpharmacological measures include liberal addition of salt to the diet, exercise, compression stockings or physical maneuvers. Severe cases may be treated with midodrine or fludrocortisone. Some results suggest that droxidopa and fipamezole may be effective treatments. We finish this review article by discussing the most important unanswered questions about PD-related OH, which may be the focus of future research.
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Affiliation(s)
- Santiago Perez-Lloret
- Clinical Pharmacology & Epidemiology Laboratory, Pontifical Catholic University, Buenos Aires, Argentina
- Departments of Clinical Pharmacology & Neurosciences, & Clinical Investigation Center CIC9302, Institut National de la Santé & de la Recherche Médicale & University Hospital, University of Toulouse III, 37 Allées Jules Guesde, 31000, Toulouse, France
| | - María Verónica Rey
- Departments of Clinical Pharmacology & Neurosciences, & Clinical Investigation Center CIC9302, Institut National de la Santé & de la Recherche Médicale & University Hospital, University of Toulouse III, 37 Allées Jules Guesde, 31000, Toulouse, France
- Clinical Pharmacology & Epidemiology Laboratory, Pontifical Catholic University, Buenos Aires, Argentina
| | - Anne Pavy-Le Traon
- Departments of Clinical Pharmacology & Neurosciences, & Clinical Investigation Center CIC9302, Institut National de la Santé & de la Recherche Médicale & University Hospital, University of Toulouse III, 37 Allées Jules Guesde, 31000, Toulouse, France
| | - Olivier Rascol
- Departments of Clinical Pharmacology & Neurosciences, & Clinical Investigation Center CIC9302, Institut National de la Santé & de la Recherche Médicale & University Hospital, University of Toulouse III, 37 Allées Jules Guesde, 31000, Toulouse, France
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Phillips AA, Krassioukov AV, Ainslie PN, Warburton DE. Baroreflex Function after Spinal Cord Injury. J Neurotrauma 2012; 29:2431-45. [DOI: 10.1089/neu.2012.2507] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Aaron A. Phillips
- Cardiovascular Physiology and Rehabilitation Laboratory, Physical Activity Promotion and Chronic Disease Prevention Unit, University of British Columbia, British Columbia, Canada
- Experimental Medicine Program, Faculty of Medicine, University of British Columbia, British Columbia, Canada
- International Collaboration of Repair Discoveries, University of British Columbia, British Columbia, Canada
| | - Andrei V. Krassioukov
- Experimental Medicine Program, Faculty of Medicine, University of British Columbia, British Columbia, Canada
- International Collaboration of Repair Discoveries, University of British Columbia, British Columbia, Canada
- Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, British Columbia, Canada
| | - Philip N. Ainslie
- School of Health and Exercise Sciences, Faculty of Health and Social Development, University of British Columbia Okanagan, Kelowna, British Columbia, Canada
| | - Darren E.R. Warburton
- Cardiovascular Physiology and Rehabilitation Laboratory, Physical Activity Promotion and Chronic Disease Prevention Unit, University of British Columbia, British Columbia, Canada
- Experimental Medicine Program, Faculty of Medicine, University of British Columbia, British Columbia, Canada
- International Collaboration of Repair Discoveries, University of British Columbia, British Columbia, Canada
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Bauman WA, Korsten MA, Radulovic M, Schilero GJ, Wecht JM, Spungen AM. 31st g. Heiner sell lectureship: secondary medical consequences of spinal cord injury. Top Spinal Cord Inj Rehabil 2012; 18:354-78. [PMID: 23459498 PMCID: PMC3584784 DOI: 10.1310/sci1804-354] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Persons with spinal cord injury (SCI) have secondary medical consequences of paralysis and/or the consequences of extreme inactivity. The metabolic changes that result from reduced activity include insulin resistance with carbohydrate disorders and dyslipidemia. A higher prevalence of coronary artery calcification was found in persons with SCI than that in matched able-bodied controls. A depression in anabolic hormones, circulating testosterone and growth hormone, has been described. Adverse soft tissue body composition changes of increased adiposity and reduced skeletal muscle are appreciated. Immobilization is the cause for sublesional disuse osteoporosis with an associated increased risk of fragility fracture. Bowel dysmotility affects all segments of the gastrointestinal tract, with an interest in better defining and addressing gastroesophageal reflux disease and difficulty with evacuation. Developing and testing more effective approaches to cleanse the bowel for elective colonoscopy are being evaluated. The extent of respiratory dysfunction depends on the level and completeness of SCI. Individuals with higher spinal lesions have both restrictive and obstructive airway disease. Pharmacological approaches and expiratory muscle training are being studied as interventions to improve pulmonary function and cough strength with the objective of reducing pulmonary complications. Persons with spinal lesions above the 6th thoracic level lack both cardiac and peripheral vascular mechanisms to maintain blood pressure, and they are frequently hypotensive, with even worse hypotension with upright posture. Persistent and/or orthostatic hypotension may predispose those with SCI to cognitive impairments. The safety and efficacy of anti-hypotensive agents to normalize blood pressure in persons with higher level cord lesions is being investigated.
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Affiliation(s)
- William A Bauman
- VA RR&D National Center of Excellence for the Medical Consequences of Spinal Cord Injury, James J. Peters VA Medical Center , Bronx, New York ; Medical Service, James J. Peters VA Medical Center , Bronx, New York ; Department of Medicine, The Mount Sinai School of Medicine , New York, New York ; Department of Rehabilitation Medicine, The Mount Sinai School of Medicine , New York, New York
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