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Kalyani P, Lippa SM, Werner JK, Amyot F, Moore CB, Kenney K, Diaz-Arrastia R. Phosphodiesterase-5 (PDE-5) Inhibitors as Therapy for Cerebrovascular Dysfunction in Chronic Traumatic Brain Injury. Neurotherapeutics 2023; 20:1629-1640. [PMID: 37697134 PMCID: PMC10684467 DOI: 10.1007/s13311-023-01430-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2023] [Indexed: 09/13/2023] Open
Abstract
Multiple phase III randomized controlled trials (RCTs) for pharmacologic interventions in traumatic brain injury (TBI) have failed despite promising results in experimental models. The heterogeneity of TBI, in terms of pathomechanisms and impacted brain structures, likely contributes to these failures. Biomarkers have been recommended to identify patients with relevant pathology (predictive biomarkers) and confirm target engagement and monitor therapy response (pharmacodynamic biomarkers). Our group focuses on traumatic cerebrovascular injury as an understudied endophenotype of TBI and is validating a predictive and pharmacodynamic imaging biomarker (cerebrovascular reactivity; CVR) in moderate-severe TBI. We aim to extend these studies to milder forms of TBI to determine the optimal dose of sildenafil for maximal improvement in CVR. We will conduct a phase II dose-finding study involving 160 chronic TBI patients (mostly mild) using three doses of sildenafil, a phosphodiesterase-5 (PDE-5) inhibitor. The study measures baseline CVR and evaluates the effect of escalating sildenafil doses on CVR improvement. A 4-week trial of thrice daily sildenafil will assess safety, tolerability, and clinical efficacy. This dual-site 4-year study, funded by the Department of Defense and registered in ClinicalTrials.gov (NCT05782244), plans to launch in June 2023. Biomarker-informed RCTs are essential for developing effective TBI interventions, relying on an understanding of underlying pathomechanisms. Traumatic microvascular injury (TMVI) is an attractive mechanism which can be targeted by vaso-active drugs such as PDE-5 inhibitors. CVR is a potential predictive and pharmacodynamic biomarker for targeted interventions aimed at TMVI. (Trial registration: NCT05782244, ClinicalTrials.gov ).
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Affiliation(s)
- Priyanka Kalyani
- Department of Neurology, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA.
| | - Sara M Lippa
- Walter Reed National Military Medical Center, The National Intrepid Center of Excellence, Palmer Rd S, Bethesda, MD, 20814, USA
- Department of Neuroscience, Uniformed Services University Health Sciences, 4301, Jones Bridge Rd, Bethesda, MD, 20814, USA
| | - J Kent Werner
- Walter Reed National Military Medical Center, The National Intrepid Center of Excellence, Palmer Rd S, Bethesda, MD, 20814, USA
- Department of Neuroscience, Uniformed Services University Health Sciences, 4301, Jones Bridge Rd, Bethesda, MD, 20814, USA
| | - Franck Amyot
- Walter Reed National Military Medical Center, The National Intrepid Center of Excellence, Palmer Rd S, Bethesda, MD, 20814, USA
| | - Carol B Moore
- Department of Neuroscience, Uniformed Services University Health Sciences, 4301, Jones Bridge Rd, Bethesda, MD, 20814, USA
| | - Kimbra Kenney
- Department of Neuroscience, Uniformed Services University Health Sciences, 4301, Jones Bridge Rd, Bethesda, MD, 20814, USA
| | - Ramon Diaz-Arrastia
- Department of Neurology, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
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2
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Wang Q, Shin B, Oh S, Shin YS, Na DL, Kim KW. A pilot study to explore the effect of udenafil on cerebral hemodynamics in older adults. Ann Clin Transl Neurol 2023; 10:933-943. [PMID: 37013976 PMCID: PMC10270257 DOI: 10.1002/acn3.51774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 04/05/2023] Open
Abstract
OBJECTIVE Phosphodiesterase-5 inhibitors (PDE5Is) enhance vasodilation. We investigated the effects of PDE5I on cerebral hemodynamics during cognitive tasks using functional near-infrared spectroscopy (fNIRS). METHODS This study used a crossover design. Twelve cognitively healthy men participants (mean age, 59 ± 3 years; range, 55-65 years) were recruited and randomly assigned to the experimental or control arm, then the experimental and control arm were exchanged after 1 week. Udenafil 100 mg was administered to participants in the experimental arm once daily for 3 days. We measured the fNIRS signal during the resting state and four cognitive tasks three times for each participant: at baseline, in the experimental arm, and in the control arm. RESULTS Behavioral data did not show a significant difference between the experimental and control arms. The fNIRS signal showed significant decreases in the experimental arm compared to the control arm during several cognitive tests: verbal fluency test (left dorsolateral prefrontal cortex, T = -3.02, p = 0.014; left frontopolar cortex, T = -4.37, p = 0.002; right dorsolateral prefrontal cortex, T = -2.59, p = 0.027), Korean-color word Stroop test (left orbitofrontal cortex, T = -3.61, p = 0.009), and social event memory test (left dorsolateral prefrontal cortex, T = -2.35, p = 0.043; left frontopolar cortex, T = -3.35, p = 0.01). INTERPRETATION Our results showed a paradoxical effect of udenafil on cerebral hemodynamics in older adults. This contradicts our hypothesis, but it suggests that fNIRS is sensitive to changes in cerebral hemodynamics in response to PDE5Is.
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Affiliation(s)
- Qi Wang
- Medical SchoolJeonbuk National UniversityJeonjuSouth Korea
| | - Byoung‐Soo Shin
- Department of NeurologyJeonbuk National University Medical School and HospitalJeonjuSouth Korea
- Research Institute of Clinical Medicine of Jeonbuk National University‐Biomedical Research Institute of Jeonbuk National University HospitalJeonjuSouth Korea
| | - Sun‐Young Oh
- Department of NeurologyJeonbuk National University Medical School and HospitalJeonjuSouth Korea
- Research Institute of Clinical Medicine of Jeonbuk National University‐Biomedical Research Institute of Jeonbuk National University HospitalJeonjuSouth Korea
| | - Yu Seob Shin
- Research Institute of Clinical Medicine of Jeonbuk National University‐Biomedical Research Institute of Jeonbuk National University HospitalJeonjuSouth Korea
- Department of UrologyJeonbuk National University Medical School and HospitalJeonjuSouth Korea
| | - Duk L. Na
- Department of NeurologySungkyunkwan University School of Medicine, Samsung Medical CenterSeoulSouth Korea
| | - Ko Woon Kim
- Department of NeurologyJeonbuk National University Medical School and HospitalJeonjuSouth Korea
- Research Institute of Clinical Medicine of Jeonbuk National University‐Biomedical Research Institute of Jeonbuk National University HospitalJeonjuSouth Korea
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3
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Justo AFO, Toscano ECDB, Farias-Itao DS, Suemoto CK. The action of phosphodiesterase-5 inhibitors on β-amyloid pathology and cognition in experimental Alzheimer's disease: A systematic review. Life Sci 2023; 320:121570. [PMID: 36921685 DOI: 10.1016/j.lfs.2023.121570] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 02/09/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023]
Abstract
Alzheimer's disease (AD) is the most frequent cause of dementia worldwide. The etiology of AD is partially explained by the deposition of β-amyloid in the brain. Despite extensive research on the pathogenesis of AD, the current treatments are ineffective. Here, we systematically reviewed studies that investigated whether phosphodiesterase 5 inhibitors (PDE5i) are efficient in reducing the β-amyloid load in hippocampi and improving cognitive decline in rodent models with β-amyloid accumulation. We identified ten original studies, which used rodent models with β-amyloid accumulation, were treated with PDE5i, and β-amyloid was measured in the hippocampi. PDE5i was efficient in reducing the β-amyloid levels, except for one study that exclusively used female rodents and the treatment did not affect β-amyloid levels. Interestingly, PDE5i prevented cognitive decline in all studies. This study supports the potential therapeutic use of PDE5i for the reduction of the β-amyloid load in hippocampi and cognitive decline. However, we highlight the importance of conducting additional experimental studies to evaluate the PDE5i-related molecular mechanisms involved in β-amyloid removal in male and female animals.
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Affiliation(s)
- Alberto Fernando Oliveira Justo
- Physiopathology in Aging Laboratory (LIM-22), Department of Internal Medicine, University of São Paulo Medical School, São Paulo, Brazil.
| | - Eliana Cristina de Brito Toscano
- Physiopathology in Aging Laboratory (LIM-22), Department of Internal Medicine, University of São Paulo Medical School, São Paulo, Brazil; Department of Pathology, Federal University of Juiz de Fora Medical School, Juiz de Fora, Brazil; Post-graduation Program in Health, Federal University of Juiz de Fora Medical School, Juiz de Fora, Brazil.
| | | | - Claudia Kimie Suemoto
- Physiopathology in Aging Laboratory (LIM-22), Department of Internal Medicine, University of São Paulo Medical School, São Paulo, Brazil; Division of Geriatrics, Department of Internal Medicine, University of São Paulo Medical School, São Paulo, Brazil.
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4
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Inocencio IM, Kaur N, Tran NT, Wong FY. Cerebral haemodynamic response to somatosensory stimulation in preterm lambs is enhanced following sildenafil and inhaled nitric oxide administration. Front Physiol 2023; 14:1101647. [PMID: 36760535 PMCID: PMC9905131 DOI: 10.3389/fphys.2023.1101647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/11/2023] [Indexed: 01/26/2023] Open
Abstract
Background: Neurovascular coupling (NVC) leads to an increase in local cerebral blood flow and oxygenation in response to increased neural activity and metabolic demand. Impaired or immature NVC reported in the preterm brain, potentially reduces cerebral oxygenation following increased neural activity, predisposing to cerebral tissue hypoxia. Endogenous nitric oxide (NO) is a potent vasodilator and a major mediator of NVC and the cerebral haemodynamic response. NO modulators, such as inhaled nitric oxide (iNO) and sildenafil, induce vasodilation and are used clinically to treat pulmonary hypertension in preterm neonates. However, their impact on NVC in the preterm brain are unknown. We aimed to characterise the cerebral functional haemodynamic response in the preterm brain exposed to NO modulators. We hypothesized that iNO and sildenafil in clinical dosages would increase the baseline cerebral perfusion and the cerebral haemodynamic response to neural activation. Methods: Preterm lambs (126-7 days' gestation) were delivered and mechanically ventilated. The cerebral functional haemodynamic response was measured using near infrared spectroscopy as changes in cerebral oxy- and deoxyhaemoglobin (ΔoxyHb, ΔdeoxyHb), following left median nerve stimulations of 1.8, 4.8, and 7.8 s durations in control preterm lambs (n = 11), and following 4.8 and 7.8 s stimulations in preterm lambs receiving either sildenafil citrate (n = 6, 1.33 mcg/kg/hr) or iNO (n = 8, 20 ppm). Results: Following 1.8, 4.8, and 7.8 s stimulations, ∆oxyHb in the contralateral cortex increased (positive functional response) in 7/11 (64%), 7/11 (64%), and 4/11 (36%) control lambs respectively (p < 0.05). Remaining lambs showed decreased ΔoxyHb (negative functional response). Following 4.8 s stimulations, more lambs receiving sildenafil or iNO (83% and 100% respectively) showed positive functional response compared to the controls (p < 0.05). No significant difference between the three groups was observed at 7.8 s stimulations. Conclusion: In the preterm brain, prolonged somatosensory stimulations increased the incidence of negative functional responses with decreased cerebral oxygenation, suggesting that cerebral oxygen delivery may not match the oxygen demand. Sildenafil and iNO increased the incidence of positive functional responses, potentially enhancing NVC, and cerebral oxygenation.
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Affiliation(s)
- Ishmael Miguel Inocencio
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Navneet Kaur
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia,Department of Paediatrics, Monash University, Melbourne, VIC, Australia
| | - Nhi T. Tran
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia
| | - Flora Y. Wong
- The Ritchie Centre, The Hudson Institute of Medical Research, Melbourne, VIC, Australia,Department of Paediatrics, Monash University, Melbourne, VIC, Australia,Monash Newborn, Monash Children’s Hospital, Melbourne, VIC, Australia,*Correspondence: Flora Y. Wong,
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5
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Burma JS, Van Roessel RK, Oni IK, Dunn JF, Smirl JD. Neurovascular coupling on trial: How the number of trials completed impacts the accuracy and precision of temporally derived neurovascular coupling estimates. J Cereb Blood Flow Metab 2022; 42:1478-1492. [PMID: 35209741 PMCID: PMC9274868 DOI: 10.1177/0271678x221084400] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Standard practices for quantifying neurovascular coupling (NVC) with transcranial Doppler ultrasound (TCD) require participants to complete one-to-ten repetitive trials. However, limited empirical evidence exists regarding how the number of trials completed influences the validity and reliability of temporally derived NVC metrics. Secondary analyses was performed on 60 young healthy participants (30 females/30 males) who completed eight cyclical eyes-closed (20-seconds), eyes-open (40-seconds) NVC trials, using the "Where's Waldo?" visual paradigm. TCD data was obtained in posterior and middle cerebral arteries (PCA and MCA, respectively). The within-day (n = 11) and between-day (n = 17) reliability were assessed at seven- and three-time points, respectively. Repeat testing from the reliability aims were also used for the concurrent validity analysis (n = 160). PCA metrics (i.e., baseline, peak, percent increase, and area-under-the-curve) demonstrated five trials produced excellent intraclass correlation coefficient (ICC) 95% confidence intervals for validity and within-day reliability (>0.900), whereas between-day reliability was good-to-excellent (>0.750). Likewise, 95% confidence intervals for coefficient of variation (CoV) measures ranged from acceptable (<20%) to excellent (<5%) with five-or-more trials. Employing fewer than five trials produced poor/unacceptable ICC and CoV metrics. Future NVC, TCD-based research should therefore have participants complete a minimum of five trials when quantifying the NVC response with TCD via a "Where's Waldo?" paradigm.
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Affiliation(s)
- Joel S Burma
- Cerebrovascular Concussion Lab, Faculty of Kinesiology, University of Calgary, Alberta, Canada.,Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute of Alberta, University of Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
| | - Rowan K Van Roessel
- Cerebrovascular Concussion Lab, Faculty of Kinesiology, University of Calgary, Alberta, Canada
| | - Ibukunoluwa K Oni
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jeff F Dunn
- Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada.,Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Radiology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Jonathan D Smirl
- Cerebrovascular Concussion Lab, Faculty of Kinesiology, University of Calgary, Alberta, Canada.,Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute of Alberta, University of Calgary, Alberta, Canada.,Alberta Children's Hospital Research Institute, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Integrated Concussion Research Program, University of Calgary, Calgary, AB, Canada
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6
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Xiong Y, Wintermark P. The Role of Sildenafil in Treating Brain Injuries in Adults and Neonates. Front Cell Neurosci 2022; 16:879649. [PMID: 35620219 PMCID: PMC9127063 DOI: 10.3389/fncel.2022.879649] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Accepted: 04/04/2022] [Indexed: 12/02/2022] Open
Abstract
Sildenafil is a recognized treatment for patients suffering from erectile dysfunction and pulmonary hypertension. However, new evidence suggests that it may have a neuroprotective and a neurorestorative role in the central nervous system of both adults and neonates. Phosphodiesterase type 5-the target of sildenafil-is distributed in many cells throughout the body, including neurons and glial cells. This study is a comprehensive review of the demonstrated effects of sildenafil on the brain with respect to its function, extent of injury, neurons, neuroinflammation, myelination, and cerebral vessels.
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Affiliation(s)
- Ying Xiong
- Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan, China
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
| | - Pia Wintermark
- Research Institute of the McGill University Health Centre, Montreal, QC, Canada
- Division of Newborn Medicine, Department of Pediatrics, Montreal Children’s Hospital, Montreal, QC, Canada
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7
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Garcia-Gonzalez MA, Vallejo-Ruiz V, Atonal-Flores F, Flores-Hernandez J, Torres-Ramírez O, Diaz-Fonsecae A, Perez Vizcaino F, Lopez-Lopez JG. Sildenafil prevents right ventricular hypertrophy and improves heart rate variability in rats with pulmonary hypertension secondary to experimental diabetes. Clin Exp Hypertens 2022; 44:355-365. [DOI: 10.1080/10641963.2022.2050743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Miguel Angel Garcia-Gonzalez
- Departamento de Farmacia, Benemerita Universidad Autonoma de Puebla, Laboratorio de Farmacia Clinica, Edificio FCQ10, Ciudad Universitaria, Col. Jardines de San Manuel, Puebla, Mexico
| | - Veronica Vallejo-Ruiz
- Instituto Mexicano del Seguro Social, Centro de Investigación Biomédica de Oriente, Laboratorio de Biología Molecular, Puebla, Mexico
| | - Fausto Atonal-Flores
- Departamento de Fisiología, Benemérita Universidad Autónoma de Puebla, Facultad de Medicina, Metepec, Mexico
| | - Jorge Flores-Hernandez
- Laboratorio de Neuromodulación, Benemerita Universidad Autonoma de Puebla, Fisiología, Puebla,Mexico
| | - Oswaldo Torres-Ramírez
- Departamento de Farmacia, Benemérita Universidad Autónoma de Puebla, Facultad de Ciencias Químicas, Puebla, Mexico
| | - Alfonso Diaz-Fonsecae
- Departamento de Farmacia, Benemérita Universidad Autónoma de Puebla, Facultad de Ciencias Químicas, Puebla, Mexico
| | - Francisco Perez Vizcaino
- Departamento de Farmacología y Toxicología, Universidad Complutense de Madrid, Escuela de Medicina, Puebla,Mexico
| | - Jose Gustavo Lopez-Lopez
- Departamento de Farmacia, Benemerita Universidad Autonoma de Puebla, Laboratorio de Farmacia Clinica, Edificio FCQ10, Ciudad Universitaria, Col. Jardines de San Manuel, Puebla, Mexico
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8
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Malenfant S, Brassard P, Paquette M, Le Blanc O, Chouinard A, Bonnet S, Provencher S. Continuous reduction in cerebral oxygenation during endurance exercise in patients with pulmonary arterial hypertension. Physiol Rep 2020; 8:e14389. [PMID: 32189447 PMCID: PMC7080869 DOI: 10.14814/phy2.14389] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Patients with pulmonary arterial hypertension (PAH) have lower cerebral blood flow (CBF) and oxygenation compared to healthy sedentary subjects, the latter negatively correlating with exercise capacity during incremental cycling exercise. We hypothesized that patients would also exhibit altered CBF and oxygenation during endurance exercise, which would correlate with endurance time. METHODS Resting and exercise cardiorespiratory parameters, blood velocity in the middle cerebral artery (MCAv; transcranial doppler) and cerebral oxygenation (relative changes in cerebral tissue oxygenation index (ΔcTOI) and cerebral deoxyhemoglobin (ΔcHHb); near-infrared spectroscopy) were continuously monitored in nine PAH patients and 10 healthy-matched controls throughout endurance exercise. Cardiac output (CO), systemic blood pressure (BP) and oxygen saturation (SpO2 ), ventilatory metrics and end-tidal CO2 pressure (PET CO2 ) were also assessed noninvasively. RESULTS Despite a lower workload and endurance oxygen consumption, similar CO and systemic BP, ΔcTOI was lower in PAH patients compared to controls (p < .01 for interaction). As expected during exercise, patients were characterized by an altered MCAv response to exercise, a lower PET CO2 and SpO2 , as wells as a higher minute-ventilation/CO2 production ratio ( V ˙ E / V ˙ CO 2 ratio). An uncoupling between changes in MCAv and PET CO2 during the cycling endurance exercise was also progressively apparent in PAH patients, but absent in healthy controls. Both cHHb and ΔcTOI correlated with V ˙ E / V ˙ CO 2 ratio (r = 0.50 and r = -0.52; both p < .05 respectively), but not with endurance time. CONCLUSION PAH patients present an abnormal cerebrovascular profile during endurance exercise with a lower cerebral oxygenation that correlate with hyperventilation but not endurance exercise time. These findings complement the physiological characterization of the cerebral vascular responses to exercise in PAH patients.
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Affiliation(s)
- Simon Malenfant
- Pulmonary Hypertension and Vascular Biology Research GroupQuebec CityQCCanada
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of MedicineFaculty of MedicineUniversité LavalQuebec CityQCCanada
- Department of KinesiologyFaculty of MedicineUniversité LavalQuebec CityQCCanada
| | - Patrice Brassard
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of KinesiologyFaculty of MedicineUniversité LavalQuebec CityQCCanada
| | - Myriam Paquette
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of KinesiologyFaculty of MedicineUniversité LavalQuebec CityQCCanada
| | - Olivier Le Blanc
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of KinesiologyFaculty of MedicineUniversité LavalQuebec CityQCCanada
| | - Audrey Chouinard
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of KinesiologyFaculty of MedicineUniversité LavalQuebec CityQCCanada
| | - Sébastien Bonnet
- Pulmonary Hypertension and Vascular Biology Research GroupQuebec CityQCCanada
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of MedicineFaculty of MedicineUniversité LavalQuebec CityQCCanada
| | - Steeve Provencher
- Pulmonary Hypertension and Vascular Biology Research GroupQuebec CityQCCanada
- Quebec Heart and Lung Institute Research CenterUniversité LavalQuebec CityQCCanada
- Department of MedicineFaculty of MedicineUniversité LavalQuebec CityQCCanada
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Ölmestig J, Marlet IR, Hansen RH, Rehman S, Krawcyk RS, Rostrup E, Lambertsen KL, Kruuse C. Tadalafil may improve cerebral perfusion in small-vessel occlusion stroke-a pilot study. Brain Commun 2020; 2:fcaa020. [PMID: 33033800 PMCID: PMC7530832 DOI: 10.1093/braincomms/fcaa020] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/22/2019] [Accepted: 12/28/2019] [Indexed: 01/29/2023] Open
Abstract
New treatments for cerebral small-vessel disease are needed to reduce the risk of small-vessel occlusion stroke and vascular cognitive impairment. We investigated an approach targeted to the signalling molecule cyclic guanosine monophosphate, using the phosphodiesterase 5 inhibitor tadalafil, to explore if it improves cerebral blood flow and endothelial function in patients with cerebral small-vessel disease and stroke. In a randomized, double-blinded, placebo-controlled, cross-over pilot trial (NCT02801032), we included patients who had a previous (>6 months) small-vessel occlusion stroke. They received a single dose of either 20 mg tadalafil or placebo on 2 separate days at least 1 week apart. We measured the following: baseline MRI for lesion load, repeated measurements of blood flow velocity in the middle cerebral artery by transcranial Doppler, blood oxygen saturation in the cortical microvasculature by near-infrared spectroscopy, peripheral endothelial response by EndoPAT and endothelial-specific blood biomarkers. Twenty patients with cerebral small-vessel disease stroke (3 women, 17 men), mean age 67.1 ± 9.6, were included. The baseline mean values ± standard deviations were as follows: blood flow velocity in the middle cerebral artery, 57.4 ± 10.8 cm/s; blood oxygen saturation in the cortical microvasculature, 67.0 ± 8.2%; systolic blood pressure, 145.8 ± 19.5 mmHg; and diastolic blood pressure, 81.3 ± 9.1 mmHg. We found that tadalafil significantly increased blood oxygen saturation in the cortical microvasculature at 180 min post-administration with a mean difference of 1.57 ± 3.02%. However, we saw no significant differences in transcranial Doppler measurements over time. Tadalafil had no effects on peripheral endothelial function assessed by EndoPAT and endothelial biomarker results conflicted. Our findings suggest that tadalafil may improve vascular parameters in patients with cerebral small-vessel disease stroke, although the effect size was small. Increased oxygenation of cerebral microvasculature during tadalafil treatment indicated improved perfusion in the cerebral microvasculature, theoretically presenting an attractive new therapeutic target in cerebral small-vessel disease. Future studies of the effect of long-term tadalafil treatment on cerebrovascular reactivity and endothelial function are needed to evaluate general microvascular changes and effects in cerebral small-vessel disease and stroke.
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Affiliation(s)
- Joakim Ölmestig
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark
| | - Ida R Marlet
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark
| | - Rasmus H Hansen
- Department of Radiology, Herlev Gentofte Hospital, Herlev 2730, Denmark
| | - Shazia Rehman
- Department of Radiology, Herlev Gentofte Hospital, Herlev 2730, Denmark
| | - Rikke Steen Krawcyk
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark.,Department of Physiotherapy and Occupational Therapy, Herlev Gentofte Hospital, Herlev 2730, Denmark
| | - Egill Rostrup
- Center for Neuropsychiatric Schizophrenia Research, Mental Health Center Glostrup, Capital Region Psychiatry, Glostrup 2600, Denmark
| | - Kate L Lambertsen
- Department of Neurobiology Research, Institute of Molecular Medicine, University of Southern Denmark, Odense 5000, Denmark.,Department of Neurology, Odense University Hospital, Odense 5000, Denmark.,BRIDGE-Brain Research Inter-Disciplinary Guided Excellence, Department of Clinical Research, University of Southern Denmark, Odense 5000, Denmark
| | - Christina Kruuse
- Department of Neurology, Neurovascular Research Unit, Herlev Gentofte Hospital, University of Copenhagen, Herlev 2730, Denmark.,Institute for Clinical Medicine, University of Copenhagen, 2200 Copenhagen N, Denmark
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10
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Hendrikx D, Smits A, Lavanga M, De Wel O, Thewissen L, Jansen K, Caicedo A, Van Huffel S, Naulaers G. Measurement of Neurovascular Coupling in Neonates. Front Physiol 2019; 10:65. [PMID: 30833901 PMCID: PMC6387909 DOI: 10.3389/fphys.2019.00065] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 01/21/2019] [Indexed: 01/01/2023] Open
Abstract
Neurovascular coupling refers to the mechanism that links the transient neural activity to the subsequent change in cerebral blood flow, which is regulated by both chemical signals and mechanical effects. Recent studies suggest that neurovascular coupling in neonates and preterm born infants is different compared to adults. The hemodynamic response after a stimulus is later and less pronounced and the stimulus might even result in a negative (hypoxic) signal. In addition, studies both in animals and neonates confirm the presence of a short hypoxic period after a stimulus in preterm infants. In clinical practice, different methodologies exist to study neurovascular coupling. The combination of functional magnetic resonance imaging or functional near-infrared spectroscopy (brain hemodynamics) with EEG (brain function) is most commonly used in neonates. Especially near-infrared spectroscopy is of interest, since it is a non-invasive method that can be integrated easily in clinical care and is able to provide results concerning longer periods of time. Therefore, near-infrared spectroscopy can be used to develop a continuous non-invasive measurement system, that could be used to study neonates in different clinical settings, or neonates with different pathologies. The main challenge for the development of a continuous marker for neurovascular coupling is how the coupling between the signals can be described. In practice, a wide range of signal interaction measures exist. Moreover, biomedical signals often operate on different time scales. In a more general setting, other variables also have to be taken into account, such as oxygen saturation, carbon dioxide and blood pressure in order to describe neurovascular coupling in a concise manner. Recently, new mathematical techniques were developed to give an answer to these questions. This review discusses these recent developments.
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Affiliation(s)
- Dries Hendrikx
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Anne Smits
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | - Mario Lavanga
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Ofelie De Wel
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Liesbeth Thewissen
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
| | - Katrien Jansen
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
- Child Neurology, University Hospitals Leuven, Leuven, Belgium
| | - Alexander Caicedo
- Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Sabine Van Huffel
- Department of Electrical Engineering, KU Leuven, Leuven, Belgium
- imec, Leuven, Belgium
| | - Gunnar Naulaers
- Department of Development and Regeneration, KU Leuven, Leuven, Belgium
- Neonatal Intensive Care Unit, University Hospitals Leuven, Leuven, Belgium
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11
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Achiron A, Hecht I, Juza C, Barak A, Burgansky-Eliash Z. The effect of sildenafil on retinal blood velocity in healthy subjects. EYE AND VISION 2018; 5:30. [PMID: 30534576 PMCID: PMC6280412 DOI: 10.1186/s40662-018-0125-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 11/20/2018] [Indexed: 01/18/2023]
Abstract
Purpose It has been suggested that Sildenafil may have beneficial therapeutic effects in the treatment of neurodegenerative disorders. The retinal circulation is of significant interest as a marker of cerebral vascular disease since the retinal and cerebral vasculatures share many morphological and physiological properties, yet only the retinal circulation can be directly visualized. Therefore, our aim was to assess the change induced by Sildenafil on retinal blood velocity. Methods Retinal flow velocity was measured 0.5, 3 and 6 h following administration of 100 mg of Sildenafil using the Retinal Function Imager. Results No clinical change in either systemic blood pressure or retinal flow velocities were observed. However, when controlling for heart rate and blood pressure, a significant drop in venous flow velocity 6 h following treatment (mean drop 0.3 ± 0.07; 95% CI: 0.44–0.56, P = 0.023) was revealed. Conclusions In healthy volunteers, retinal venous flow velocity was significantly reduced at the 6-h time point following Sildenafil treatment. No effect was observed on arterial retinal flow velocity.
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Affiliation(s)
- Asaf Achiron
- 1Department of Ophthalmology, Edith Wolfson Medical Center, 62 Halochamim St, 58100 Holon, Israel.,2Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Idan Hecht
- 1Department of Ophthalmology, Edith Wolfson Medical Center, 62 Halochamim St, 58100 Holon, Israel.,2Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Chen Juza
- 2Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,3Department of Urology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Adiel Barak
- 2Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.,4Department of Ophthalmology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel
| | - Zvia Burgansky-Eliash
- 1Department of Ophthalmology, Edith Wolfson Medical Center, 62 Halochamim St, 58100 Holon, Israel.,2Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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12
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Sheng M, Lu H, Liu P, Li Y, Ravi H, Peng SL, Diaz-Arrastia R, Devous MD, Womack KB. Sildenafil Improves Vascular and Metabolic Function in Patients with Alzheimer's Disease. J Alzheimers Dis 2018; 60:1351-1364. [PMID: 29036811 DOI: 10.3233/jad-161006] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND Alzheimer's disease (AD) is the leading cause of degenerative dementia in the aging population. Patients with AD have alterations in cerebral hemodynamic function including reduced cerebral blood flow (CBF) and cerebral metabolic rate. Therefore, improved cerebrovascular function may be an attractive goal for pharmaceutical intervention in AD. OBJECTIVE We wished to observe the acute effects of sildenafil on cerebrovascular function and brain metabolism in patients with AD. METHODS We used several novel non-invasive MRI techniques to investigate the alterations of CBF, cerebral metabolic rate of oxygen (CMRO2), and cerebrovascular reactivity (CVR) after a single dose of sildenafil administration in order to assess its physiological effects in patients with AD. CBF, CMRO2, and CVR measurements using MRI were performed before and one hour after the oral administration of 50 mg sildenafil. Baseline Montreal Cognitive Assessment score was also obtained. RESULTS Complete CBF and CMRO2 data were obtained in twelve patients. Complete CVR data were obtained in eight patients. Global CBF and CMRO2 significantly increased (p = 0.03, p = 0.05, respectively) following sildenafil administration. Voxel-wise analyses of CBF maps showed that increased CBF was most pronounced in the bilateral medial temporal lobes. CVR significantly decreased after administration of sildenafil. CONCLUSION Our data suggest that a single dose of sildenafil improves cerebral hemodynamic function and increases cerebral oxygen metabolism in patients with AD.
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Affiliation(s)
- Min Sheng
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, Beijing Eden Hospital, Beijing, China
| | - Hanzhang Lu
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Peiying Liu
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yang Li
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Harshan Ravi
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Shin-Lei Peng
- Advanced Imaging Research Center, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Radiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Biomedical Imaging and Radiological Science, China Medical University, Taichung, Taiwan
| | - Ramon Diaz-Arrastia
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Penn Presbyterian Medical Center, Philadelphia, PA, USA
| | - Michael D Devous
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Kyle B Womack
- Department of Neurology and Neurotherapeutics, The University of Texas Southwestern Medical Center, Dallas, TX, USA.,Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX, USA
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13
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Pauls MMH, Moynihan B, Barrick TR, Kruuse C, Madigan JB, Hainsworth AH, Isaacs JD. The effect of phosphodiesterase-5 inhibitors on cerebral blood flow in humans: A systematic review. J Cereb Blood Flow Metab 2018; 38:189-203. [PMID: 29256324 PMCID: PMC5951021 DOI: 10.1177/0271678x17747177] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/17/2017] [Accepted: 10/20/2017] [Indexed: 11/29/2022]
Abstract
Agents that augment cerebral blood flow (CBF) could be potential treatments for vascular cognitive impairment. Phosphodiesterase-5 inhibitors are vasodilating drugs established in the treatment of erectile dysfunction (ED) and pulmonary hypertension. We reviewed published data on the effects of phosphodiesterase-5 inhibitors on CBF in adult humans. A systematic review according to PRISMA guidelines was performed. Embase, Medline and Cochrane Library Trials databases were searched. Sixteen studies with 353 participants in total were retrieved. Studies included healthy volunteers and patients with migraine, ED, type 2 diabetes, stroke, pulmonary hypertension, Becker muscular dystrophy and subarachnoid haemorrhage. Most studies used middle cerebral artery flow velocity to estimate CBF. Few studies employed direct measurements of tissue perfusion. Resting CBF velocity was unaffected by phosphodiesterase-5 inhibitors, but cerebrovascular regulation was improved in ED, pulmonary hypertension, diabetes, Becker's and a group of healthy volunteers. This evidence suggests that phosphodiesterase-5 inhibitors improve responsiveness of the cerebral vasculature, particularly in disease states associated with an impaired endothelial dilatory response. This supports the potential therapeutic use of phosphodiesterase-5 inhibitors in vascular cognitive impairment where CBF is reduced. Further studies with better resolution of deep CBF are warranted. The review is registered on the PROSPERO database (registration number CRD42016029668).
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Affiliation(s)
- Mathilde MH Pauls
- Molecular and Clinical Sciences Research
Institute, St George's University of London, London, UK
- Department of Neurology, St George's
University Hospitals NHS Foundation Trust, London, UK
| | - Barry Moynihan
- Department of Neurology, St George's
University Hospitals NHS Foundation Trust, London, UK
- Department of Geriatric and Stroke
Medicine, Beaumont Hospital, Dublin, Ireland
| | - Thomas R Barrick
- Molecular and Clinical Sciences Research
Institute, St George's University of London, London, UK
| | - Christina Kruuse
- Department of Neurology, Neurovascular
Research Unit, Herlev Gentofte Hospital and University of Copenhagen, Denmark
| | - Jeremy B Madigan
- Department of Neuroradiology, St
George's University Hospitals NHS Foundation Trust, London, UK
| | - Atticus H Hainsworth
- Molecular and Clinical Sciences Research
Institute, St George's University of London, London, UK
- Department of Neurology, St George's
University Hospitals NHS Foundation Trust, London, UK
| | - Jeremy D Isaacs
- Molecular and Clinical Sciences Research
Institute, St George's University of London, London, UK
- Department of Neurology, St George's
University Hospitals NHS Foundation Trust, London, UK
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14
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Dhar R, Washington C, Diringer M, Zazulia A, Jafri H, Derdeyn C, Zipfel G. Acute Effect of Intravenous Sildenafil on Cerebral Blood Flow in Patients with Vasospasm After Subarachnoid Hemorrhage. Neurocrit Care 2017; 25:201-4. [PMID: 26940913 DOI: 10.1007/s12028-016-0243-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
BACKGROUND The phosphodiesterase-5 inhibitor sildenafil has been shown to attenuate delayed cerebral ischemia (DCI) and improve neurologic function in experimental subarachnoid hemorrhage (SAH). We recently demonstrated that it could improve cerebral vasospasm (CVS) in humans after SAH. However, successful therapies for DCI must also restore cerebral blood flow (CBF) and/or autoregulatory capacity. In this study, we tested the effects of sildenafil on CBF in SAH patients at-risk for DCI. METHODS Six subjects with angiographically confirmed CVS received 30-mg of intravenous sildenafil (mean 9 ± 2 days after aneurysmal SAH). Each underwent (15)O-PET imaging to measure global and regional CBF at baseline and post-sildenafil. RESULTS Mean arterial pressure declined by 10 mm Hg on average post-sildenafil (8 %, p = 0.01), while ICP was unchanged. There was no change in global CBF (mean 34.5 ± 7 ml/100g/min at baseline vs. 33.9 ± 8.0 ml/100g/min post-sildenafil, p = 0.84). The proportion of brain regions with low CBF (<25 ml/100g/min) was also unchanged after sildenafil infusion. CONCLUSIONS Infusion of sildenafil does not lead to a change in global or regional perfusion despite a significant reduction in cerebral perfusion pressure. While this could reflect the ineffectiveness of sildenafil-induced proximal vasodilatation to alter brain perfusion, it also suggests that cerebral autoregulatory function was preserved in this group. Future studies should assess whether sildenafil can restore or enhance autoregulation after SAH.
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Affiliation(s)
- Rajat Dhar
- Division of Neurocritical Care, Department of Neurology, Washington University in St. Louis, 660 S Euclid Avenue, St. Louis, MO, 63110, USA.
| | - Chad Washington
- Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Michael Diringer
- Division of Neurocritical Care, Department of Neurology, Washington University in St. Louis, 660 S Euclid Avenue, St. Louis, MO, 63110, USA.,Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Allyson Zazulia
- Division of Neurocritical Care, Department of Neurology, Washington University in St. Louis, 660 S Euclid Avenue, St. Louis, MO, 63110, USA.,Department of Radiology, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Hussain Jafri
- Department of Radiology, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Colin Derdeyn
- Division of Neurocritical Care, Department of Neurology, Washington University in St. Louis, 660 S Euclid Avenue, St. Louis, MO, 63110, USA.,Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO, 63110, USA.,Department of Radiology, Washington University in St. Louis, St. Louis, MO, 63110, USA
| | - Gregory Zipfel
- Division of Neurocritical Care, Department of Neurology, Washington University in St. Louis, 660 S Euclid Avenue, St. Louis, MO, 63110, USA.,Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO, 63110, USA
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15
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Malenfant S, Brassard P, Paquette M, Le Blanc O, Chouinard A, Nadeau V, Allan PD, Tzeng YC, Simard S, Bonnet S, Provencher S. Compromised Cerebrovascular Regulation and Cerebral Oxygenation in Pulmonary Arterial Hypertension. J Am Heart Assoc 2017; 6:e006126. [PMID: 29025748 PMCID: PMC5721836 DOI: 10.1161/jaha.117.006126] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 08/28/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Functional cerebrovascular regulatory mechanisms are important for maintaining constant cerebral blood flow and oxygen supply in heathy individuals and are altered in heart failure. We aim to examine whether pulmonary arterial hypertension (PAH) is associated with abnormal cerebrovascular regulation and lower cerebral oxygenation and their physiological and clinical consequences. METHODS AND RESULTS Resting mean flow velocity in the middle cerebral artery mean flow velocity in the middle cerebral artery (MCAvmean); transcranial Doppler), cerebral pressure-flow relationship (assessed at rest and during squat-stand maneuvers; analyzed using transfer function analysis), cerebrovascular reactivity to CO2, and central chemoreflex were assessed in 11 patients with PAH and 11 matched healthy controls. Both groups also completed an incremental ramp exercise protocol until exhaustion, during which MCAvmean, mean arterial pressure, cardiac output (photoplethysmography), end-tidal partial pressure of CO2, and cerebral oxygenation (near-infrared spectroscopy) were measured. Patients were characterized by a significant decrease in resting MCAvmean (P<0.01) and higher transfer function gain at rest and during squat-stand maneuvers (both P<0.05). Cerebrovascular reactivity to CO2 was reduced (P=0.03), whereas central chemoreceptor sensitivity was increased in PAH (P<0.01), the latter correlating with increased resting ventilation (R2=0.47; P<0.05) and the exercise ventilation/CO2 production slope (V˙E/V˙CO2 slope; R2=0.62; P<0.05) during exercise for patients. Exercise-induced increases in MCAvmean were limited in PAH (P<0.05). Reduced MCAvmean contributed to impaired cerebral oxygen delivery and oxygenation (both P<0.05), the latter correlating with exercise capacity in patients with PAH (R2=0.52; P=0.01). CONCLUSIONS These findings provide comprehensive evidence for physiologically and clinically relevant impairments in cerebral hemodynamic regulation and oxygenation in PAH.
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Affiliation(s)
- Simon Malenfant
- Pulmonary Hypertension and Vascular Biology Research Group, Université Laval, Quebec City, Canada
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec City, Canada
| | - Patrice Brassard
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec City, Canada
| | - Myriam Paquette
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec City, Canada
| | - Olivier Le Blanc
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec City, Canada
| | - Audrey Chouinard
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec City, Canada
| | - Valérie Nadeau
- Pulmonary Hypertension and Vascular Biology Research Group, Université Laval, Quebec City, Canada
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
| | - Philip D Allan
- Wellington Medical Technology Group, Center for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Yu-Chieh Tzeng
- Wellington Medical Technology Group, Center for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Sébastien Simard
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
| | - Sébastien Bonnet
- Pulmonary Hypertension and Vascular Biology Research Group, Université Laval, Quebec City, Canada
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Canada
| | - Steeve Provencher
- Pulmonary Hypertension and Vascular Biology Research Group, Université Laval, Quebec City, Canada
- Quebec Heart and Lung Institute Research Center, Université Laval, Quebec City, Canada
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, Canada
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16
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Munshi A, Das S. Genetic Understanding of Stroke Treatment: Potential Role for Phosphodiesterase Inhibitors. ADVANCES IN NEUROBIOLOGY 2017; 17:445-461. [PMID: 28956342 DOI: 10.1007/978-3-319-58811-7_16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Phosphodiesterase (PDE) gene family is a large family having at least 21 genes and multiple versions (isoforms) of the phosphodiesterase enzymes. These enzymes catalyze the inactivation of intracellular mediators of signal transduction such as cAMP and cGMP and therefore, play a pivotal role in various cellular functions. PDE inhibitors (PDEI) are drugs that block one or more of the five subtypes of the PDE family and thereby prevent inactivation of the intracellular cAMP and cGMP by the respective PDE-subtypes. The first clinical use of PDEI was reported almost three decades ago. Studies later found the ability of these compounds to increase the levels of ubiquitous secondary messenger molecules that can cause changes in vascular tone, cardiac function and other cellular events and thus these findings paved the way for their use in various medical emergencies. PDEs are found to be distributed in many tissues including brain. Therefore, new therapeutic agents in the form of PDEI are being explored in neurodegenerative diseases including stroke. Although studies have revealed their use in cerebral infarction prevention, their full-fledged application in times of neurological emergency or stroke in specific has been very limited so far. Nevertheless, recent investigations suggest PDE4 and PDE5 inhibitors to play a vital role in mitigating stroke symptoms by modulating signaling mechanisms in PDE pathway. Further, extensive research in terms of their pharmacological properties like dosing, drug specific activities, use of simultaneous medications, ancillary properties of these compounds and studies on adverse drug reactions needs to be carried out to set them as standard drugs of use in stroke.
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Affiliation(s)
- Anjana Munshi
- Centre for Human Genetics and Molecular Medicine, School of Health Sciences, Central University of Punjab, Bathinda, Punjab, India.
| | - Satrupa Das
- Institute of Genetics and Hospital for Genetic Diseases, Osmania University, Begumpet, Hyderabad, 500016, India
- Dr. NTR University of Health Sciences, Vijayawada, Andhra Pradesh, India
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17
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Lindberg U, Witting N, Jørgensen SL, Vissing J, Rostrup E, Larsson HBW, Kruuse C. Effects of Sildenafil on Cerebrovascular Reactivity in Patients with Becker Muscular Dystrophy. Neurotherapeutics 2017; 14:182-190. [PMID: 27485237 PMCID: PMC5233618 DOI: 10.1007/s13311-016-0467-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Patients suffering from Becker muscular dystrophy (BMD) have dysfunctional dystrophin proteins and are deficient in neuronal nitric oxide synthase (nNOS) in muscles. This causes functional ischemia and contributes to muscle wasting. Similar functional ischemia may be present in brains of patients with BMD, who often have mild cognitive impairment, and nNOS may be important for the regulation of the microvascular circulation in the brain. We hypothesized that treatment with sildenafil, a phosphodiesterase type 5 inhibitor that potentiates nitric oxide responses, would augment both the blood oxygen level-dependent (BOLD) response and cerebral blood flow (CBF) in patients with BMD. Seventeen patients (mean ± SD age 38.5 ± 10.8 years) with BMD were included in this randomized, double-blind, placebo-controlled, crossover trial. Twelve patients completed the entire study. Effects of sildenafil were assessed by 3 T magnetic resonance (MR) scanning, evoked potentials, somatosensory task-induced BOLD functional MR imaging, regional and global perfusion, and angiography before and after 4 weeks of sildenafil, 20 mg (Revatio in gelatine capsules, oral, 3 times daily), or placebo treatment. Sildenafil increased the event-related sensory and visual BOLD response compared with placebo (p < 0.01). However, sildenafil did not alter CBF, measured by MR phase contrast mapping, or the arterial diameter of the middle cerebral artery, measured by MR angiography. We conclude that nNOS may play a role in event-related neurovascular responses. Further studies in patients with BMD may help clarify the roles of dystrophin and nNOS in neurovascular coupling in general, and in patients with BMD in particular.
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Affiliation(s)
- Ulrich Lindberg
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS), Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Nanna Witting
- Copenhagen Neuromuscular Center and Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Stine Lundgaard Jørgensen
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS), Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - John Vissing
- Copenhagen Neuromuscular Center and Department of Neurology, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Egill Rostrup
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Henrik Bo Wiberg Larsson
- Functional Imaging Unit, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS), Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Christina Kruuse
- Lundbeck Foundation Center for Neurovascular signalling (LUCENS), Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark.
- Neurovascular Research Unit, Department of Neurology, Herlev Gentofte Hospital, University of Copenhagen, Herlev, Denmark.
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18
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Abstract
Antidementive drugs have made Alzheimer's disease a symptomatically treatable condition but have essentially bypassed vascular dementia. The complexity of its pathology, the variable pathognomonic manifestations, the absence of validated biomarkers and the continuum with Alzheimer's disease that makes vascular dementia a comparatively small market are the major contributing factors. This report discusses how drug repurposing can be harnessed to identify new therapeutic opportunities, where such efforts are already yielding promising results, and which ones must be considered failures. Most investigations address obvious aspects cerebral small vessel disease, but some early-stage developments attempt changes in gene expression or modulation of complex biological pathways. A stronger focus on the nature and dynamics of white matter lesions should yield additional molecular targets.
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Affiliation(s)
- Hermann AM Mucke
- HM Pharma Consultancy, Enenkelstrasse 28/32, A-1160 Vienna, Austria
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19
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Wang L, Chopp M, Szalad A, Lu X, Jia L, Lu M, Zhang RL, Zhang ZG. Tadalafil Promotes the Recovery of Peripheral Neuropathy in Type II Diabetic Mice. PLoS One 2016; 11:e0159665. [PMID: 27438594 PMCID: PMC4954704 DOI: 10.1371/journal.pone.0159665] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 07/05/2016] [Indexed: 12/16/2022] Open
Abstract
We previously demonstrated that treatment of diabetic peripheral neuropathy with the short (4 hours) half-life phosphodiesterase 5 (PDE5) inhibitor, sildenafil, improved functional outcome in diabetic db/db mice. To further examine the effect of PDE5 inhibition on diabetic peripheral neuropathy, we investigated the effect of another potent PDE5 inhibitor, tadalafil, on diabetic peripheral neuropathy. Tadalafil is pharmacokinetically distinct from sildenafil and has a longer half-life (17+hours) than sildenafil. Diabetic mice (BKS.Cg-m+/+Leprdb/J, db/db) at age 20 weeks were treated with tadalafil every 48 hours for 8 consecutive weeks. Compared with diabetic mice treated with saline, tadalafil treatment significantly improved motor and sensory conduction velocities in the sciatic nerve and peripheral thermal sensitivity. Tadalafil treatment also markedly increased local blood flow and the density of FITC-dextran perfused vessels in the sciatic nerve concomitantly with increased intraepidermal nerve fiber density. Moreover, tadalafil reversed the diabetes-induced reductions of axon diameter and myelin thickness and reversed the diabetes-induced increased g-ratio in the sciatic nerve. Furthermore, tadalafil enhanced diabetes-reduced nerve growth factor (NGF) and platelet-derived growth factor-C (PDGF-C) protein levels in diabetic sciatic nerve tissue. The present study demonstrates that tadalafil increases regional blood flow in the sciatic nerve tissue, which may contribute to the improvement of peripheral nerve function and the amelioration of diabetic peripheral neuropathy.
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Affiliation(s)
- Lei Wang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
- * E-mail:
| | - Michael Chopp
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
- Department of Physics, Oakland University, Rochester, Michigan, 48309, United States of America
| | - Alexandra Szalad
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - XueRong Lu
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - LongFei Jia
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Mei Lu
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Rui Lan Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Hospital, 2799 W. Grand Boulevard, Detroit, Michigan, 48202, United States of America
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Katusic ZS, Austin SA. Neurovascular Protective Function of Endothelial Nitric Oxide - Recent Advances. Circ J 2016; 80:1499-503. [PMID: 27238834 DOI: 10.1253/circj.cj-16-0423] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In the central nervous system endothelial nitric oxide (NO) is an essential molecule responsible for the preservation of the functional integrity of the neurovascular unit. NO causes vasodilatation and is an important inhibitor of platelet aggregation, smooth muscle cell proliferation, and white blood cell adhesion. In addition, endothelium-derived NO exerts anti-inflammatory and pro-angiogenic effects. More recently, it has been recognized that endothelial NO modulates the expression and processing of amyloid precursor protein in cerebrovascular endothelium and neuronal tissue. Studies in endothelial NO synthase (eNOS) knockout mice indicate that endothelial NO functions as a neurovascular protective molecule during aging. Indeed, genetic inactivation of eNOS exacerbates the detrimental effects of aging on cerebrovascular, microglial, and neuronal functions as well as on cognition. These findings suggest that the preservation of healthy endothelium and normal function of eNOS might be important therapeutic targets. Because the beneficial effects of NO are mostly mediated by the activation of guanylate cyclase/cyclic GMP signaling, inhibitors of phosphodiesterase isoforms, or activation of this signaling with exercise, may offer therapeutic opportunities in the prevention and treatment of aging-induced cognitive decline and Alzheimer's disease. Most recent advances in understanding the molecular mechanisms linking loss of endothelial NO with cognitive decline will be discussed in this review. (Circ J 2016; 80: 1499-1503).
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Affiliation(s)
- Zvonimir S Katusic
- Department of Anesthesiology and Molecular Pharmacology & Experimental Therapeutics, Mayo Clinic
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Akkerman S, Blokland A, van Goethem NP, Cremers P, Shaffer CL, Osgood SM, Steinbusch HWM, Prickaerts J. PDE5 inhibition improves acquisition processes after learning via a central mechanism. Neuropharmacology 2015; 97:233-9. [PMID: 26027948 DOI: 10.1016/j.neuropharm.2015.04.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 04/11/2015] [Accepted: 04/18/2015] [Indexed: 10/23/2022]
Abstract
In previous studies, we have shown that phosphodiesterase type 5 inhibitors (PDE5-Is) can improve early consolidation of object memory. These conclusions were based on the timing of drug administration relative to the learning trial (i.e. before or after). However, there are very little pharmacological data available about the pharmacokinetic profile of orally administered PDE5-Is in the rat. Furthermore, there is still debate whether these effects are achieved via central or peripheral mechanisms and if acquisition processes are improved. In the current study, we tested the effects of the PDE5-I vardenafil in a cholinergic-deficit model and compared the effects after intracerebroventricular (ICV) versus oral (PO) administration. We found that PO vardenafil restored a scopolamine-induced memory impairment when dosed within 2 min after the learning trial while ICV vardenafil was able to restore memory when injected within 4 min after learning. Because the test trial was within 10 min after the learning trial, this suggests that these effects on object memory are related to acquisition processes that may still be ongoing in a time window after the learning trial. To further elucidate the extent of this acquisition window, we investigated the pharmacokinetic profile of vardenafil after PO administration where it was detected within 4 min post-dose. Taken together, our data suggest that PDE5 is involved in acquisition processes, which may linger for at least 4-6 min after learning. Further studies are needed to exclude that these effects could also be explained on basis of an effect on early consolidation processes. Additionally, the effectiveness of ICV-administered vardenafil provides further experimental evidence that PDE5-Is improve memory via a central mechanism.
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Affiliation(s)
- S Akkerman
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - A Blokland
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - N P van Goethem
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - P Cremers
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - C L Shaffer
- Department of Pharmacokinetics, Pharmacodynamics and Metabolism, Worldwide Research & Development, Pfizer Inc., Eastern Point Road, Groton, CT 06340, USA
| | - S M Osgood
- Department of Pharmacokinetics, Pharmacodynamics and Metabolism, Worldwide Research & Development, Pfizer Inc., Eastern Point Road, Groton, CT 06340, USA
| | - H W M Steinbusch
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands
| | - J Prickaerts
- Department of Psychiatry and Neuropsychology, Faculty of Health, Medicine and Life Sciences, European School of Neuroscience (EURON), Maastricht University, Maastricht, The Netherlands.
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Sildenafil attenuates hepatocellular injury after liver ischemia reperfusion in rats: a preliminary study. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:161942. [PMID: 24999378 PMCID: PMC4066851 DOI: 10.1155/2014/161942] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 05/16/2014] [Accepted: 05/19/2014] [Indexed: 01/17/2023]
Abstract
We evaluated the role of sildenafil in a rat liver ischemia-reperfusion model. Forty male rats were randomly allocated in four groups. The sham group underwent midline laparotomy only. In the sildenafil group, sildenafil was administered intraperitoneally 60 minutes before sham laparotomy. In the ischemia-reperfusion (I/R) group, rats were subjected to 45 minutes of hepatic ischemia followed by 120 minutes of reperfusion, while in the sild+I/R group rats were subjected to a similar pattern of I/R after the administration of sildenafil, 60 minutes before ischemia. Two hours after reperfusion, serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured and histopathological examination of the lobes subjected to ischemia as well as TUNEL staining for apoptotic bodies was performed. Additionally, myeloperoxidase (MPO) activity and the expression of intercellular adhesion molecule-1 (ICAM-1) were analyzed. Serum markers of hepatocellular injury were significantly lower in the sild+I/R group, which also exhibited lower severity of histopathological lesions and fewer apoptotic bodies, as compared to the I/R group. The I/R group showed significantly higher MPO activity and higher expression of ICAM-1, as compared to the sild+I/R group. Use of sildenafil as a preconditioning agent in a rat model of liver I/R exerted a protective effect.
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Damar E, Toklu Y, Tuncel A, Balci M, Aslan Y, Simsek S, Atan A. Does therapeutic dose of sildenafil citrate treatment lead to central serous chorioretinopathy in patients with erectile dysfunction? Am J Mens Health 2013; 7:439-43. [PMID: 23479433 DOI: 10.1177/1557988313480808] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The possible effects of sildenafil citrate administration at therapeutic dosage on visual acuity, color vision, intraocular pressure, macular thickness, macular volume, and central serous chorioretinopathy in patients with erectile dysfunction were evaluated. The study consisted of 43 male patients diagnosed as having erectile dysfunction according to the first five question version of International Index of Erectile Function (IIEF-5). All patients were given sildenafil citrate 50 mg po 2 to 3 times/week for a month. The patients were evaluated at the first week and at the end of the treatment. The macular thickness and volume assessments with optic coherence tomography did not differ significantly in foveal, parafoveal areas, parafoveal superior hemisphere, parafoveal inferior hemisphere, parafoveal temporal, superior, nasal, and inferior quadrants. Central serous chorioretinopathy was not found in any of the patients.
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Affiliation(s)
- Elif Damar
- Ministry of Health, Ankara Ataturk Research and Training Hospital, Department of Ophthalmology, Ankara, Turkey
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Boeck L, Tamm M, Grendelmeier P, Stolz D. Acute effects of aerosolized iloprost in COPD related pulmonary hypertension - a randomized controlled crossover trial. PLoS One 2012; 7:e52248. [PMID: 23300624 PMCID: PMC3531427 DOI: 10.1371/journal.pone.0052248] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 11/16/2012] [Indexed: 12/02/2022] Open
Abstract
Background Inhaled iloprost potentially improves hemodynamics and gas exchange in patients with chronic obstructive pulmonary disease (COPD) and secondary pulmonary hypertension (PH). Objectives To evaluate acute effects of aerosolized iloprost in patients with COPD-associated PH. Methods A randomized, double blind, crossover study was conducted in 16 COPD patients with invasively confirmed PH in a single tertiary care center. Each patient received a single dose of 10 µg iloprost (low dose), 20 µg iloprost (high dose) and placebo during distinct study-visits. The primary end-point of the study was exercise capacity as assessed by the six minute walking distance. Results Both iloprost doses failed to improve six-minute walking distance (p = 0.36). Low dose iloprost (estimated difference of the means −1.0%, p = 0.035) as well as high dose iloprost (−2.2%, p<0.001) significantly impaired oxygenation at rest. Peak oxygen consumption and carbon dioxide production differed significantly over the three study days (p = 0.002 and p = 0.003, accordingly). As compared to placebo, low dose iloprost was associated with reduced peak oxygen consumption (−76 ml/min, p = 0.002), elevated partial pressure of carbon dioxide (0.27 kPa, p = 0.040) and impaired ventilation during exercise (−3.0l/min, p<0.001). Conclusions Improvement of the exercise capacity after iloprost inhalation in patients with COPD-associated mild to moderate PH is very unlikely. Trial Registration Controlled-Trials.com ISRCTN61661881
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Affiliation(s)
- Lucas Boeck
- Clinic of Pulmonary Medicine and Respiratory Cell Research, University Hospital Basel, Basel, Switzerland
| | - Michael Tamm
- Clinic of Pulmonary Medicine and Respiratory Cell Research, University Hospital Basel, Basel, Switzerland
| | - Peter Grendelmeier
- Clinic of Pulmonary Medicine and Respiratory Cell Research, University Hospital Basel, Basel, Switzerland
| | - Daiana Stolz
- Clinic of Pulmonary Medicine and Respiratory Cell Research, University Hospital Basel, Basel, Switzerland
- * E-mail:
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Bates MGD, Thompson AAR, Baillie JK, Sutherland AI, Irving JB, Hirani N, Webb DJ. Sildenafil citrate for the prevention of high altitude hypoxic pulmonary hypertension: double blind, randomized, placebo-controlled trial. High Alt Med Biol 2012; 12:207-14. [PMID: 21962063 DOI: 10.1089/ham.2011.0007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Exaggerated hypoxic pulmonary vasoconstriction is a key factor in the development of high altitude pulmonary edema (HAPE). Due to its effectiveness as a pulmonary vasodilator, sildenafil has been proposed as a prophylactic agent against HAPE. By conducting a parallel-group double blind, randomized, placebo-controlled trial, we investigated the effect of chronic sildenafil administration on pulmonary artery systolic pressure (PASP) and symptoms of acute mountain sickness (AMS) during acclimatization to high altitude. Sixty-two healthy lowland volunteers (36 male; median age 21 years, range 18 to 31) on the Apex 2 research expedition were flown to La Paz, Bolivia (3650 m), and after 4-5 days acclimatization ascended over 90 min to 5200 m. The treatment group (n=20) received 50 mg sildenafil citrate three times daily. PASP was recorded by echocardiography at sea level and within 6 h, 3 days, and 1 week at 5200 m. AMS was assessed daily using the Lake Louise Consensus symptom score. On intention-to-treat analysis, there was no significant difference in PASP at 5200 m between sildenafil and placebo groups. Median AMS score on Day 2 at 5200 m was significantly higher in the sildenafil group (placebo 4.0, sildenafil 6.5; p=0.004) but there was no difference in prevalence of AMS between groups. Sildenafil administration did not affect PASP in healthy lowland subjects at 5200 m but AMS was significantly more severe on Day 2 at 5200 m with sildenafil. Our data do not support routine prophylactic use of sildenafil to reduce PASP at high altitude in healthy subjects with no history of HAPE. TRIALS REGISTRATION NUMBER: NCT00627965.
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Affiliation(s)
- Matthew G D Bates
- Mitochondrial Research Group, Medical School, Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom.
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Al-Amran FG, Zwain AAMH, Hadi NR, Al-Mudhaffer AM. Autonomic cerebral vascular response to sildenafil in diabetic patient. Diabetol Metab Syndr 2012; 4:2. [PMID: 22284589 PMCID: PMC3292818 DOI: 10.1186/1758-5996-4-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Accepted: 01/27/2012] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Erectile dysfunction is a common problem in type 2 diabetic patients who are at higher risk of cerebrovascular events, and it's recorded with sildenafil, a drug which is primarily used for erectile dysfunction. OBJECTIVES We tested the hypothesis whether or not sildenafil modulates cerebrovascular reactivity (CVR) in patients with type 2 diabetes mellitus. METHODS A total of 35 male participants were enrolled; eighteen with type 2 diabetes mellitus matched with seventeen normal individuals. Transcranial Doppler Ultrasonographic examination (TCD) was performed for all participants to insonate the middle cerebral artery (MCA) through a trans-temporal window. CVR was assessed by using breath holding (BH)-hyperventilation (HV) test, before and after oral 50 mg sildenafil; recordings were analyzed by using SPSS program version 12. RESULTS In normal individuals, sildenafil did not result in statistically significant change in breath holding index (BHI) from 0.91 ± 0.11 to 0.81 ± 0.09 and full range of vasodilatation (FVD) from (59.4% ± 6.3%) to (53.7% ± 4.9%). In diabetic patients, giving sildenafil resulted in significant increase in BHI (from 0.74 ± 0.14 to 1.03 ± 0.14) and FVD (from 60.2% ± 4.96% to 74% ± 4.8%), (p < 0.05). CONCLUSION Sildenafil significantly improves CVR in type 2 diabetic patients but not in normal subjects.
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Affiliation(s)
- Fadhil G Al-Amran
- FRCS, FACS, Department of Surgery, postal code 474, Medical college Kufa University, Kufa Najaf street, Najaf, Iraq
| | - Akeel AMH Zwain
- Department of Cardiovascular Physiology, postal code 474, Medical college Kufa University, Kufa Najaf street, Najaf, Iraq
| | - Najah R Hadi
- Department of Pharmacology, postal code 474, Medical college Kufa University, Kufa Najaf street, Najaf, Iraq
| | - Ahmed M Al-Mudhaffer
- Department of Pharmacology, postal code 474, Medical college Kufa University, Kufa Najaf street, Najaf, Iraq
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Schudt C, Hatzelmann A, Beume R, Tenor H. Phosphodiesterase inhibitors: history of pharmacology. Handb Exp Pharmacol 2011:1-46. [PMID: 21695634 DOI: 10.1007/978-3-642-17969-3_1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The first pharmacological investigations of phosphodiesterase (PDE) inhibitors were developed with the clinical efficacies of drugs isolated from coffee, cacao and tea but only later their relevant ingredients were identified as xanthines that act as PDE. With its diuretic, inotropic and bronchodilating clinical efficacy, use of theophylline anticipated the clinical goals, which were later approached with the first-generation of weakly selective PDE inhibitors in the period from 1980 to 1990. Pharmacological and clinical research with these early compounds provided a vast pool of information regarding desired and adverse actions - although most of these new drugs had to be discontinued due to severe adverse effects. The pharmacological models for cardiac, vascular and respiratory indications were analysed for their PDE isoenzyme profiles, and when biochemical and molecular biological approaches expanded our knowledge of the PDE superfamily, the purified isoenzymes that were now available opened the door for more systematic studies of inhibitors and for generation of highly selective isoenzyme-specific drugs. The development of simple screening models and clinically relevant indication models reflecting the growing knowledge about pathomechanisms of disease are summarised here for today's successful application of highly selective PDE3, PDE4 and PDE5 inhibitors. The interplay of serendipitous discoveries, the establishment of intelligent pharmacological models and the knowledge gain by research results with new substances is reviewed. The broad efficacies of new substances in vitro, the enormous biodiversity of the PDE isoenzyme family and the sophisticated biochemical pharmacology enabled Viagra to be the first success story in the field of PDE inhibitor drug development, but probably more success stories will follow.
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Affiliation(s)
- Christian Schudt
- Department of Biologics, Nycomed GmbH, 78467, Konstanz, Germany.
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Rolita L, Verghese J. Neurovascular coupling: Key to gait slowing in aging? Ann Neurol 2011; 70:189-91. [DOI: 10.1002/ana.22503] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Rosengarten B, Paulsen S, Burr O, Kaps M. Effect of ApoE epsilon4 allele on visual evoked potentials and resultant flow coupling in patients with Alzheimer. J Geriatr Psychiatry Neurol 2010; 23:165-70. [PMID: 20430978 DOI: 10.1177/0891988710363711] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The apolipoprotein E epsilon4 (ApoE epsilon4) allele is a strong susceptibility factor for Alzheimer disease, which promotes neurodegeneration and cerebrovascular dysfunction. To address this issue in more detail, we simultaneously obtained visual evoked potentials and resultant hemodynamic responses in newly diagnosed Alzheimer patients without signs of vascular lesions on a cerebral magnetic resonance imaging (MRI) scan. Patients were grouped according to ApoE genotype (n = 19 ApoE epsilon4 carrier and n = 12 noncarrier). ApoE epsilon4 carrier had significantly longer peak latencies and a trend to higher interpeak latencies of late potential components. Potential amplitudes and hemodynamic responses were similar in both groups. At the incidental stage of disease process, it appears that the ApoE epsilon4 allele mainly promotes neuronal dysfunction rather than aggravates neurovascular dysfunction. Studies with larger patient samples are warranted to corroborate the first findings.
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Romanini CV, Schiavon AP, Ferreira EDF, de Oliveira RMW, Milani H. Sildenafil prevents mortality and reduces hippocampal damage after permanent, stepwise, 4-vessel occlusion in rats. Brain Res Bull 2010; 81:631-40. [DOI: 10.1016/j.brainresbull.2009.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 12/22/2009] [Indexed: 11/30/2022]
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Kehat R, Bonsall DJ, North R, Connors B. Ocular findings of oral sildenafil use in term and near-term neonates. J AAPOS 2010; 14:159-62. [PMID: 20199882 DOI: 10.1016/j.jaapos.2009.12.161] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2009] [Revised: 12/02/2009] [Accepted: 12/11/2009] [Indexed: 10/19/2022]
Abstract
BACKGROUND Sildenafil is a phosphodiesterase type 5 inhibitor used as a therapeutic adjunct in critically ill neonates with persistent pulmonary hypertension. Sildenafil is associated with several ocular complications in adults and is suspected to exacerbate retinopathy of prematurity (ROP). The risk of ocular complication in sildenafil-treated newborns, not otherwise at risk for the development of ROP, is unknown. METHODS Twenty-two neonates with birth gestational age greater than 34 weeks and birth weight over 2,100 g who received oral sildenafil for more than 2 weeks were assessed by a pediatric ophthalmologist for potential ocular complications. RESULTS Four patients had ocular findings: 2 had bacterial conjunctivitis; 1 had optic nerve hypoplasia, choroidal coloboma, and nystagmus; 1 had previously suffered from a hypotensive episode and had a documented cortical injury accompanied by bilateral optic disk atrophy and nystagmus. All cases seemed unrelated to sildenafil use and improved despite continued use of the drug. CONCLUSIONS Our results do not support the need for a routine ophthalmologic examination in term and near-term neonates receiving sildenafil.
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Affiliation(s)
- Rinat Kehat
- Israel Institute of Technology, Haifa, Israel
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Schlindwein P, Eicke BM, Stoeter P, Dieterich M. Sildenafil improves scotoma after posterior cerebral infarctions: a case report. J Neurol 2009; 257:674-7. [PMID: 20037762 DOI: 10.1007/s00415-009-5434-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2009] [Revised: 11/19/2009] [Accepted: 12/16/2009] [Indexed: 11/25/2022]
Abstract
A 65-year-old man had an embolic stroke of both posterior cerebral arteries in 2002. Two years later he noted rapid improvement of the residual bilateral inferior quadrant anopia whenever he took 25 mg sildenafil. The improvement of scotomas was verified by visual field examinations and persisted reproducibly for 3-7 days. An overlay of a subtraction of functional magnetic resonance imaging (MRI) during visual stimulation before and after medication onto a T1-weighted MRI of the patient revealed additional activations along the margins of the old cerebral infarctions. These findings and the additional results of a perfusion MRI suggest that phosphodiesterase 5 inhibitors may prove beneficial in the rehabilitative course after ischemic strokes.
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Abstract
Phosphodiesterase type 5 (PDE5) inhibitors are effective oral treatments for erectile dysfunction and have become one of the most widely prescribed medications worldwide. The mechanism of action is to reduce the degradation of cyclic GMP (cGMP) potentiating the effect of nitric oxide in the corpus cavernosum and allowing erectile function to occur by consequent relaxation of penile smooth muscle. Because of the presence of PDE5 in choroidal and retinal vessels these medications increase choroidal blood flow and cause vasodilation of the retinal vasculature. The most common symptoms are a blue tinge to vision and an increased sensitivity to light. There have been reports of non-arteritic anterior ischaemic optic neuropathy and serous macular detachment in users of PDE5 inhibitors, although a causal relationship has not been conclusively shown. Despite the role of cGMP in the production and drainage of aqueous humour these medications do not appear to alter intraocular pressure and are safe in patients with glaucoma. All PDE5 inhibitors weakly inhibit PDE6 located in rod and cone photoreceptors resulting in mild and transient visual symptoms that correlate with plasma concentrations. Psychophysical tests reveal no effect on visual acuity, visual fields or contrast sensitivity; however, some studies show a mild and reversible impairment of blue-green colour discrimination. PDE5 inhibitors transiently alter retinal function on electroretinogram testing but do not appear to be retinotoxic. Despite the role of cyclic nucleotides in tear production there is no detrimental effect on tear film quality. Based on the available evidence PDE5 inhibitors have a good ocular safety profile.
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Affiliation(s)
- Nathan M Kerr
- Department of Ophthalmology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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Abstract
Sildenafil (Viagra), a cyclic guanosine monophosphate-degrading phosphodiesterase 5 inhibitor, induces headache and migraine. Such headache induction may be caused by an increased neuronal excitability, as no concurrent effect on cerebral arteries is found. In 13 healthy females (23+/-3 years, 70.3+/-6.6 kg), the effect of sildenafil on a visual (reversing checkerboard) and a hypercapnic (6% CO2 inhalation) response was evaluated using functional magnetic resonance imaging (fMRI, 3 T MR scanner). On separate occasions, visual-evoked potential (VEP) measurements (latency (P100) and maximal amplitude) were performed. The measurements were applied at baseline and at both 1 and 2 h after ingestion of 100 mg of sildenafil. Blood pressure, heart rate and side effects, including headache, were obtained. Headache was induced in all but one subject on both study days. Sildenafil did not affect VEP amplitude or latency (P100). The fMRI response to visual stimulation or hypercapnia was unchanged by sildenafil. In conclusion, sildenafil induces mild headache without potentiating a neuronal or local cerebrovascular visual response or a global cerebrovascular hypercapnic response. The implication is that sildenafil-induced headache does not include a general lowering of threshold for a neuronal or cerebrovascular response, and that sildenafil does not modulate the hypercapnic response in healthy subjects.
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Toda N, Ayajiki K, Okamura T. Cerebral Blood Flow Regulation by Nitric Oxide: Recent Advances. Pharmacol Rev 2009; 61:62-97. [DOI: 10.1124/pr.108.000547] [Citation(s) in RCA: 268] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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PDE5 inhibitors and pulmonary hypertension. CURRENT SEXUAL HEALTH REPORTS 2008. [DOI: 10.1007/s11930-008-0031-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Rosengarten B, Paulsen S, Burr O, Kaps M. Neurovascular coupling in Alzheimer patients: effect of acetylcholine-esterase inhibitors. Neurobiol Aging 2008; 30:1918-23. [PMID: 18395940 DOI: 10.1016/j.neurobiolaging.2008.02.017] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2007] [Revised: 01/25/2008] [Accepted: 02/22/2008] [Indexed: 11/15/2022]
Abstract
Dualistic effects of acetylcholine-esterase inhibitors on neuronal as well as vasoregulative function have been debated. This study investigated for the first time effects of medication on both components. Visually evoked potentials and resultant hemodynamic responses were assessed in Alzheimer patients (n=31) without vascular lesions in a MRI scan and compared to controls (n=20). After baseline recordings (AD0) tests were repeated under 2x1.5 to 2x3mg (AD1) and 2x4.5 to 2x6mg (AD2) rivastigmine/d. Long-term effects were investigated under 6 months of medication (AD2L). The ADAS, MMSE and DEMTECT were used to assess cognitive function at AD0, AD2 and AD2L. Improvement in vasoregulative function was independent from changes in evoked potentials. Acetylcholine-esterase inhibitors demonstrate substantial vascular effects in humans, which are independent from changes in neuronal function.
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Affiliation(s)
- Bernhard Rosengarten
- Department of Neurology, Am Steg 14, Justus-Liebig University of Giessen, 35392 Giessen, Germany.
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Lewis GD, Shah R, Shahzad K, Camuso JM, Pappagianopoulos PP, Hung J, Tawakol A, Gerszten RE, Systrom DM, Bloch KD, Semigran MJ. Sildenafil improves exercise capacity and quality of life in patients with systolic heart failure and secondary pulmonary hypertension. Circulation 2007; 116:1555-62. [PMID: 17785618 DOI: 10.1161/circulationaha.107.716373] [Citation(s) in RCA: 355] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Patients with systolic heart failure (HF) who develop secondary pulmonary hypertension (PH) have reduced exercise capacity and increased mortality compared with HF patients without PH. We tested the hypothesis that sildenafil, an effective therapy for pulmonary arterial hypertension, would lower pulmonary vascular resistance and improve exercise capacity in patients with HF complicated by PH. METHODS AND RESULTS Thirty-four patients with symptomatic HF and PH were randomized to 12 weeks of treatment with sildenafil (25 to 75 mg orally 3 times daily) or placebo. Patients underwent cardiopulmonary exercise testing before and after treatment. The change in peak VO2 from baseline, the primary end point, was greater in the sildenafil group (1.8+/-0.7 mL x kg(-1) x min(-1)) than in the placebo group (-0.27 mL x kg(-1) x min(-1); P=0.02). Sildenafil reduced pulmonary vascular resistance and increased cardiac output with exercise (P<0.05 versus placebo for both) without altering pulmonary capillary wedge or mean arterial pressure, heart rate, or systemic vascular resistance. The ability of sildenafil treatment to augment peak VO2 correlated directly with baseline resting pulmonary vascular resistance (r=0.74, P=0.002) and indirectly with baseline resting right ventricular ejection fraction (r=-0.64, P=0.01). Sildenafil treatment also was associated with improvement in 6-minute walk distance (29 m versus placebo; P=0.047) and Minnesota Living With Heart Failure score (-14 versus placebo; P=0.01). Subjects in the sildenafil group experienced fewer hospitalizations for HF and a higher incidence of headache than those in the placebo group without incurring excess serious adverse events. CONCLUSIONS Phosphodiesterase 5 inhibition with sildenafil improves exercise capacity and quality of life in patients with systolic HF with secondary PH.
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Affiliation(s)
- Gregory D Lewis
- Cardiology Division, Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Sandner P, Hütter J, Tinel H, Ziegelbauer K, Bischoff E. PDE5 inhibitors beyond erectile dysfunction. Int J Impot Res 2007; 19:533-43. [PMID: 17625575 DOI: 10.1038/sj.ijir.3901577] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The phosphodiesterase type-5 (PDE5) inhibitors sildenafil, vardenafil and tadalafil are widely used first-line therapy for erectile dysfunction (ED). Since the advent of sildenafil in 1998, more than 40 million men worldwide have been successfully treated with these compounds. The safety and high tolerability of PDE5 inhibitors make them an attractive tool to investigate further physiological functions of PDE5, for example the modulation of intracellular cyclic GMP (cGMP) pools. As cGMP is a key component of intracellular signaling this may provide novel therapeutic opportunities beyond ED even for indications in which chronic administration is necessary. The approval of sildenafil for the treatment of pulmonary hypertension in 2005 was a notable success in this area of research. A number of other potential new indications are currently in various phases of preclinical research and development. In recent years, extensive but very heterogeneous information has been published in this field. The aim of this review is to summarize existing preclinical and clinical knowledge and critically discuss the evidence to support potential future indications for PDE5 inhibitors.
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Affiliation(s)
- P Sandner
- Product-Related Research, Bayer HealthCare, Wuppertal, Germany
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Arboix A, Alsina M, Massons J. Infarto cerebral de tipo lacunar tras ingesta de sildenafilo. Med Clin (Barc) 2007; 128:398-9. [PMID: 17386250 DOI: 10.1016/s0025-7753(07)72605-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Shim JK, Choi YS, Oh YJ, Kim DH, Hong YW, Kwak YL. Effect of oral sildenafil citrate on intraoperative hemodynamics in patients with pulmonary hypertension undergoing valvular heart surgery. J Thorac Cardiovasc Surg 2006; 132:1420-5. [PMID: 17140970 DOI: 10.1016/j.jtcvs.2006.08.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 07/14/2006] [Accepted: 08/25/2006] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Pulmonary hypertension remains a major problem during the perioperative period for surgical correction of long-standing valvular heart disease. Sildenafil citrate (INN sildenafil) is a selective phosphodiesterase type 5 inhibitor that is being increasingly recognized as a treatment modality for pulmonary hypertension. There is lack of evidence, however, regarding its pulmonary vasodilatory effect in anesthetized cardiac surgical patients. We therefore evaluated the effects of sildenafil on hemodynamics in patients with concomitant pulmonary hypertension undergoing valvular heart surgery in a controlled, prospective, randomized, double-blind trial. METHODS Fifty-three patients scheduled for valvular heart surgery with mean pulmonary arterial pressure greater than 30 mm Hg were randomly treated with either 50 mg oral sildenafil (n = 26) or placebo (n = 27) 10 minutes before induction of anesthesia. Hemodynamic variables were measured 5 minutes after induction of anesthesia (baseline) and at 30 and 60 minutes after medication. RESULTS Patient characteristics and baseline hemodynamics were similar between groups. Systolic and mean pulmonary arterial pressures and pulmonary vascular resistance were significantly lower in the sildenafil group at 30 minutes after medication, without any changes in mean systemic arterial pressure and systemic vascular resistance. CONCLUSION Sildenafil produced significant pulmonary vasodilatory effect relative to placebo in anesthetized cardiac surgical patients with pulmonary hypertension. With respect to the predominant selectivity of sildenafil to pulmonary vasculature shown in this study and other potentially beneficial effects such as myocardial protection, use of sildenafil in the intraoperative period in cardiac surgical patients with pulmonary hypertension should be considered.
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Affiliation(s)
- Jae Kwang Shim
- Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, South Korea
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Ghofrani HA, Osterloh IH, Grimminger F. Sildenafil: from angina to erectile dysfunction to pulmonary hypertension and beyond. Nat Rev Drug Discov 2006; 5:689-702. [PMID: 16883306 PMCID: PMC7097805 DOI: 10.1038/nrd2030] [Citation(s) in RCA: 388] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
In less than 20 years, the first selective type 5 phosphodiesterase inhibitor, sildenafil, has evolved from a potential anti-angina drug to an on-demand oral treatment for erectile dysfunction (Viagra), and more recently to a new orally active treatment for pulmonary hypertension (Revatio). Here we describe the key milestones in the development of sildenafil for these diverse medical conditions, discuss the advances in science and clinical medicine that have accompanied this journey and consider possible future indications for this versatile drug.
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Affiliation(s)
- Hossein A Ghofrani
- Medical Clinic II/V, Department of Internal Medicine, University Hospital Giessen and Marburg, GmbH, Klinikstrasse 36, 35392 Giessen, Germany.
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