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Belbis MD, Yap Z, Hobart SE, Ferguson SK, Hirai DM. Effects of acute phosphodiesterase type 5 inhibition on skeletal muscle interstitial PO 2 during contractions and recovery. Nitric Oxide 2024; 142:16-25. [PMID: 37979932 DOI: 10.1016/j.niox.2023.11.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 10/26/2023] [Accepted: 11/14/2023] [Indexed: 11/20/2023]
Abstract
The oxygen partial pressure within the interstitial space (PO2is; mmHg) provides the driving force for oxygen diffusion into the myocyte thereby supporting oxidative phosphorylation. We tested the hypothesis that potentiation of the nitric oxide pathway with sildenafil (phosphodiesterase type 5 inhibitor) would enhance PO2is during muscle metabolic transitions, thereby slowing PO2is on- and accelerating PO2is off-kinetics. The rat spinotrapezius muscle (n = 17) was exposed for PO2is measurements via phosphorescence quenching under control (CON), low-dose sildenafil (1 mg/kg i.a., SIL1) and high-dose sildenafil (7 mg/kg i.a., SIL7). Data were collected at rest and during submaximal twitch contractions (1 Hz, 4-6 V, 3 min) and recovery (3 min). Mean arterial blood pressure (MAP; mmHg) was reduced with both SIL1 (pre:132 ± 5; post:99 ± 5) and SIL7 (pre:111 ± 6; post:99 ± 4) (p < 0.05). SIL7 elevated resting PO2is (18.4 ± 1.1) relative to both CON (15.7 ± 0.7) and SIL1 (15.2 ± 0.7) (p < 0.05). In addition, SIL7 increased end-recovery PO2is (17.7 ± 1.6) compared to CON (12.8 ± 0.9) and SIL1 (13.4 ± 0.8) (p < 0.05). The overall PO2is response during recovery (i.e., area under the PO2is curve) was greater in SIL7 (4107 ± 444) compared to CON (3493 ± 222) and SIL1 (3114 ± 205 mmHg s) (p < 0.05). Contrary to our hypothesis, there was no impact of acute SIL (1 or 7 mg/kg) on the speed of the PO2is response during contractions or recovery (p > 0.05). However, sildenafil lowered MAP and improved skeletal muscle interstitial oxygenation in healthy rats. Specifically, SIL7 enhanced PO2is at rest and during recovery from submaximal muscle contractions. Potentiation of the nitric oxide pathway with sildenafil enhances microvascular blood-myocyte O2 transport and is expected to improve repeated bouts of contractile activity.
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Affiliation(s)
- Michael D Belbis
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA; Department of Exercise Science, Aurora University, Aurora, IL, USA
| | - Zhen Yap
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Sara E Hobart
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA
| | - Scott K Ferguson
- Department of Human Factors and Behavioral Neurobiology, Embry-Riddle Aeronautical University, Daytona Beach, FL, USA
| | - Daniel M Hirai
- Department of Health and Kinesiology, Purdue University, West Lafayette, IN, USA.
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Whyte E, Thomas S, Marzolini S. Muscle oxygenation of the paretic and nonparetic legs during and after exercise in chronic stroke: Implications for mobility. PM R 2023; 15:1239-1248. [PMID: 36459570 DOI: 10.1002/pmrj.12927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 10/18/2022] [Accepted: 11/14/2022] [Indexed: 12/05/2022]
Abstract
BACKGROUND Oxygen delivery and demand are reduced in the paretic leg of individuals after stroke. However, it is unknown how muscle oxygenation, the balance between delivery and utilization of oxygen at the muscle, is altered post-stroke during aerobic exercise and how it relates to mobility. OBJECTIVE To monitor muscle oxygenation changes between the paretic and nonparetic legs of individuals after stroke during treadmill exercise and the 6-minute walk test and analyze the association with mobility. DESIGN Cross-sectional study. SETTING Cardiac rehabilitation program. PATIENTS Eleven male participants were enrolled in the study. Ten men (30.8 ± 4.1 months post-stroke; age 63.9 ± 13.9 years) with hemiparetic gait pattern finished the study. METHODS OR INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Muscle oxygenation was measured with near-infrared spectroscopy placed on the vastus lateralis of each leg during treadmill exercise at the first ventilatory threshold and during a 6-minute walk test. RESULTS The desaturation slope during treadmill exercise was significantly steeper (p = .047) in the paretic (-0.7 ± 0.6%/s) compared to the nonparetic leg (-0.3 ± 0.2%/s). There was no other significant difference between legs. The 6-minute walk test distance was not correlated with 6-minute walk test muscle oxygenation in either leg (paretic: r = 0.20, p = 0.590; nonparetic: r = 0.42, p = .232). CONCLUSIONS At the onset of treadmill exercise, the paretic leg was unable to effectively match the oxygen demand and extraction of the nonparetic leg, suggesting the need for an immediate cardiovascular warmup prior to initiating moderate intensity exercise in this population. Because the exercise desaturation rate is thought to indicate increased anaerobic metabolism and lactate production, efforts to delay rapid desaturation could improve the sustainability of activities of daily living and exercise.
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Affiliation(s)
- Elizabeth Whyte
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network, Toronto, Ontario, Canada
| | - Scott Thomas
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network, Toronto, Ontario, Canada
- Rehabilitation Sciences Institute, University of Toronto, Toronto, Ontario, Canada
| | - Susan Marzolini
- Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, Ontario, Canada
- KITE Research Institute, Toronto Rehabilitation Institute - University Health Network, Toronto, Ontario, Canada
- Rehabilitation Sciences Institute, University of Toronto, Toronto, Ontario, Canada
- Canadian Partnership for Stroke Recovery, Toronto, Ontario, Canada
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Luck JC, Sica CT, Blaha C, Cauffman A, Vesek J, Eckenrode J, Stavres J. Agreement between multiparametric MRI (PIVOT), Doppler ultrasound, and near-infrared spectroscopy-based assessments of skeletal muscle oxygenation and perfusion. Magn Reson Imaging 2023; 96:27-37. [PMID: 36396004 PMCID: PMC9789193 DOI: 10.1016/j.mri.2022.11.003] [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] [Received: 08/08/2022] [Revised: 10/24/2022] [Accepted: 11/03/2022] [Indexed: 11/16/2022]
Abstract
Skeletal muscle perfusion and oxygenation are commonly evaluated using Doppler ultrasound and near-infrared spectroscopy (NIRS) techniques. However, a recently developed magnetic resonance imaging (MRI) sequence, termed PIVOT, permits the simultaneous collection of skeletal muscle perfusion and T2* (an index of skeletal muscle oxygenation). PURPOSE To determine the level of agreement between PIVOT, Doppler ultrasound, and NIRS-based assessments of skeletal muscle perfusion and oxygenation. METHODS Twelve healthy volunteers (8 females, 25 ± 3 years, 170 ± 11 cm, 71.5 ± 8.0 kg) performed six total reactive hyperemia protocols. During three of these reactive hyperemia protocols, Tissue Saturation Index (TSI) and oxygenated hemoglobin (O2Hb) were recorded from the medial gastrocnemius (MG) and tibialis anterior (TA), and blood flow velocity was recorded from the popliteal artery (BFvpop) via Doppler Ultrasound. The other three trials were performed inside the bore of a 3 T MRI scanner, and the PIVOT sequence was used to assess perfusion (PIVOTperf) and oxygenation (T2*) of the medial gastrocnemius and tibialis anterior muscles. Positive incremental areas under the curve (iAUC) and times to peak (TTP) were calculated for each variable, and the level of agreement between collection methods was evaluated via Bland-Altman analyses and Spearman's Rho correlation analyses. RESULTS The only significant bivariate relationships observed were between the T2* vs. TSI iAUC and PIVOTperf vs. BFvpop values recorded from the MG. Significant mean differences were observed for all comparisons (all P ≤ 0.038), and significant proportional biases were observed for the PIVOTperf vs. tHb TTP (R2 = 0.848, P < 0.001) and T2* vs. TSI TTP comparisons in the TA (R2 = 0.488, P = 0.011), and the PIVOTperf vs. BFvpop iAUC (R2 = 0.477, P = 0.013) and time to peak (R2 = 0.851, P < 0.001) comparisons in the MG. CONCLUSIONS Our findings suggest that the PIVOT technique has, at best, a moderate level of agreement with Doppler ultrasound and NIRS assessment methods and is subject to significant proportional bias. These findings do not challenge the accuracy of either measurement technique but instead reflect differences in the vascular compartments, sampling volumes, and parameters being evaluated.
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Affiliation(s)
- J Carter Luck
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, PA, United States of America
| | - Christopher T Sica
- Department of Radiology, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, PA, United States of America
| | - Cheryl Blaha
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, PA, United States of America
| | - Aimee Cauffman
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, PA, United States of America
| | - Jeffrey Vesek
- Department of Molecular Biology, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, PA, United States of America
| | - John Eckenrode
- School of Medicine, University of South Carolina, Columbia, SC, United States of America
| | - Jon Stavres
- Penn State Heart and Vascular Institute, Pennsylvania State University College of Medicine, Milton S. Hershey Medical Center, Hershey, PA, United States of America; School of Kinesiology and Nutrition, University of Southern Mississippi, Hattiesburg, MS, United States of America.
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Pham T, Butler A, Weideman RA, Annaswamy TM. Phosphodiesterase 5 Inhibitor Use in Patients Undergoing Decompression Surgery for Lumbar Spinal Stenosis. Am J Phys Med Rehabil 2022; 101:341-347. [PMID: 34121069 DOI: 10.1097/phm.0000000000001821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Our objectives were to explore the association between phosphodiesterase 5 inhibitor use and lumbar decompression surgery by evaluating the prevalence of lumbar decompression surgery in a treatment group of patients with lumbar spinal stenosis compared with a control group. DESIGN We performed database review and extracted data including lumbar decompression surgery prevalence, phosphodiesterase 5 inhibitor dosage, and fill dates. Treatment group was defined as those with phosphodiesterase 5 inhibitor fill dates of less than 30 days before surgery, and control group was defined as those with phosphodiesterase 5 inhibitor fill dates at any other time. Lumbar decompression surgery prevalence rates for both groups were calculated. RESULTS Our study found 599 lumbar spinal stenosis patients who were prescribed phosphodiesterase 5 inhibitor. Three hundred thirty-eight underwent lumbar decompression surgery. Of these, 71 (21%) filled their prescription of less than 30 days before surgery, whereas 267 (79%) filled their prescription during a different period. The majority (94.6%) of surgical patients received decompression at two or more spinal levels. CONCLUSIONS Prevalence of lumbar decompression surgery for lumbar spinal stenosis was significantly lower in patients in the treatment group on phosphodiesterase 5 inhibitor therapy compared with the control group. Among many potential explanations, the vasodilatory effect of phosphodiesterase 5 inhibitor may have contributed to a lower surgical rate. This is the first study to explore this novel association. Future prospective studies are necessary to better define the utility of phosphodiesterase 5 inhibitor in lumbar spinal stenosis.
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Affiliation(s)
- Tri Pham
- From the University of Texas Southwestern Medical Center, Dallas, Texas (TP); University of Cincinnati College of Medicine, Cincinnati, Ohio (AB); Pharmacy Service, VA North Texas Health Care System, Dallas, Texas (RAW); Physical Medicine and Rehabilitation Service, VA North Texas Health Care System, Dallas, Texas (TMA); and Department of Physical Medicine and Rehabilitation, University of Texas Southwestern Medical Center, Dallas, Texas (TMA)
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Skeletal Muscle Mitochondrial Dysfunction and Oxidative Stress in Peripheral Arterial Disease: A Unifying Mechanism and Therapeutic Target. Antioxidants (Basel) 2020; 9:antiox9121304. [PMID: 33353218 PMCID: PMC7766400 DOI: 10.3390/antiox9121304] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/15/2020] [Accepted: 12/16/2020] [Indexed: 12/12/2022] Open
Abstract
Peripheral artery disease (PAD) is caused by atherosclerosis in the lower extremities, which leads to a spectrum of life-altering symptomatology, including claudication, ischemic rest pain, and gangrene requiring limb amputation. Current treatments for PAD are focused primarily on re-establishing blood flow to the ischemic tissue, implying that blood flow is the decisive factor that determines whether or not the tissue survives. Unfortunately, failure rates of endovascular and revascularization procedures remain unacceptably high and numerous cell- and gene-based vascular therapies have failed to demonstrate efficacy in clinical trials. The low success of vascular-focused therapies implies that non-vascular tissues, such as skeletal muscle and oxidative stress, may substantially contribute to PAD pathobiology. Clues toward the importance of skeletal muscle in PAD pathobiology stem from clinical observations that muscle function is a strong predictor of mortality. Mitochondrial impairments in muscle have been documented in PAD patients, although its potential role in clinical pathology is incompletely understood. In this review, we discuss the underlying mechanisms causing mitochondrial dysfunction in ischemic skeletal muscle, including causal evidence in rodent studies, and highlight emerging mitochondrial-targeted therapies that have potential to improve PAD outcomes. Particularly, we will analyze literature data on reactive oxygen species production and potential counteracting endogenous and exogenous antioxidants.
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Saberi N, Akhgari M, Bahmanabadi L, Bazmi E, Mousavi Z. Determination of synthetic pharmaceutical adulterants in herbal weight gain supplements sold in herb shops, Tehran, Iran. Daru 2018; 26:117-127. [PMID: 30242673 PMCID: PMC6279663 DOI: 10.1007/s40199-018-0216-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/04/2018] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Nowadays with the growing popularity of herbal remedies across the world, large sections of population rely on herbal drug practitioners for their primary care. Therefore there is a need to ensure about the safety of herbal drugs and to detect adulteration with undeclared active pharmaceutical ingredients. Herbal drugs are used as first-line drug therapy in some instances. Unfortunately even if there are claims as to be natural, undeclared active pharmaceutical ingredients have been detected in these supplements. OBJECTIVES The purpose of the present study was to analyse herbal weight gain drugs collected from herb shops located in Tehran, Iran to detect hidden pharmaceutical ingredients using UHPLC and GC/MS instrumentations. METHODS Sixty herbal drugs advertised as weight gain supplements were gathered from herb shops Tehran province, Iran. All samples were analysed from analytical toxicology point of view to detect undeclared active pharmaceutical ingredients. Method was validated for quantitative analysis of cyproheptadine and dexamethasone. RESULTS Method validity parameters showed good results for quantitative analysis of pharmaceutical ingredients. Cyproheptadine, dexamethasone, sildenafil, tramadol, caffeine and acetaminophen were detected in herbal weight gain drugs. Analysed dosage forms contained cyproheptadine and dexamethasone in concentrations higher than therapeutic doses. Quantitative analysis of contaminated drugs showed that the content of pharmacologic ingredients were 0.2-67 and 5.5-10.1 mg/tablet or capsule for cyproheptadine and dexamethasone respectively. CONCLUSIONS Despite natural supplements producers' claim, herbal weight gain drugs were not natural at all. Undeclared active pharmaceutical ingredients can predispose patients to health problems and even life-threatening situations. Graphical Abstract ᅟ.
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Affiliation(s)
- Niosha Saberi
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran
| | - Maryam Akhgari
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran.
| | - Leila Bahmanabadi
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
| | - Elham Bazmi
- Legal Medicine Research Center, Legal Medicine Organization, Tehran, Iran
| | - Zahra Mousavi
- Department of Toxicology & Pharmacology, Faculty of Pharmacy, Pharmaceutical Sciences Branch, Islamic Azad University (IAUPS), Tehran, Iran
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Luck JC, Miller AJ, Aziz F, Radtka JF, Proctor DN, Leuenberger UA, Sinoway LI, Muller MD. Blood pressure and calf muscle oxygen extraction during plantar flexion exercise in peripheral artery disease. J Appl Physiol (1985) 2017; 123:2-10. [PMID: 28385920 DOI: 10.1152/japplphysiol.01110.2016] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/14/2017] [Accepted: 04/05/2017] [Indexed: 12/14/2022] Open
Abstract
Peripheral artery disease (PAD) is an atherosclerotic vascular disease that affects 200 million people worldwide. Although PAD primarily affects large arteries, it is also associated with microvascular dysfunction, an exaggerated blood pressure (BP) response to exercise, and high cardiovascular mortality. We hypothesized that fatiguing plantar flexion exercise that evokes claudication elicits a greater reduction in skeletal muscle oxygenation (SmO2) and a higher rise in BP in PAD compared with age-matched healthy subjects, but low-intensity steady-state plantar flexion elicits similar responses between groups. In the first experiment, eight patients with PAD and eight healthy controls performed fatiguing plantar flexion exercise (from 0.5 to 7 kg for up to 14 min). In the second experiment, seven patients with PAD and seven healthy controls performed low-intensity plantar flexion exercise (2.0 kg for 14 min). BP, heart rate (HR), and SmO2 were measured continuously using near-infrared spectroscopy (NIRS). SmO2 is the ratio of oxygenated hemoglobin to total hemoglobin, expressed as a percent. At fatigue, patients with PAD had a greater increase in mean arterial BP (18 ± 2 vs. vs. 10 ± 2 mmHg, P = 0.029) and HR (14 ± 2 vs. 6 ± 2 beats/min, P = 0.033) and a greater reduction in SmO2 (-54 ± 10 vs. -12 ± 4%, P = 0.001). However, both groups had similar physiological responses to low-intensity, nonpainful plantar flexion exercise. These data suggest that patients with PAD have altered oxygen uptake and/or utilization during fatiguing exercise coincident with an augmented BP response.NEW & NOTEWORTHY In this laboratory study, patients with peripheral artery disease performed plantar flexion exercise in the supine posture until symptoms of claudication occurred. Relative to age- and sex-matched healthy subjects we found that patients had a higher blood pressure response, a higher heart rate response, and a greater reduction in skeletal muscle oxygenation as determined by near-infrared spectroscopy. Our data suggest that muscle ischemia contributes to the augmented exercise pressor reflex in peripheral artery disease.
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Affiliation(s)
- J Carter Luck
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
| | - Amanda J Miller
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
| | - Faisal Aziz
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
| | - John F Radtka
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
| | - David N Proctor
- Department of Kinesiology, Noll Laboratory, The Pennsylvania State University, Hershey, Pennsylvania
| | - Urs A Leuenberger
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
| | - Lawrence I Sinoway
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
| | - Matthew D Muller
- Penn State Heart and Vascular Institute, The Pennsylvania State University College of Medicine, Hershey Pennsylvania; and
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9
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Omarjee L, Camarzana A, Henni S, Abraham P. Nonrevascularizable buttock claudication improved with Sildenafil: A case report. Medicine (Baltimore) 2017; 96:e6186. [PMID: 28225505 PMCID: PMC5569413 DOI: 10.1097/md.0000000000006186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
RATIONALE Sildenafil, a phosphodiesterase-5-inhibitor (PDE5i), could represent a new treatment in addition to the medical treatment and advice to walk in peripheral arterial disease (PAD). PATIENT CONCERNS AND DIAGNOSES We report a case of a 62-year-old heavy smoker man who developed a buttock claudication and a severe walking limitation following an aorto-bi-femoral bypass in 1992. Since 2003, each year, he has been referred for investigation of bilateral buttock claudication on treadmill using transcutaneous oxygen pressure (tcpO2) measurement during exercise to argue for the vascular origin of the walking impairment. He had a severe bilateral buttock ischemia and the maximum walking distance (MWD) he reached was 258 m in 2011 despite the medical optimal treatment and walking rehabilitation. Ethical approval is not necessary for this case report according to the French legislation and written consent to publication was obtained from the patient. INTERVENTIONS Sildenafil, 100 mg/d, was introduced in February 2015 and the MWD increased to 310 m only after 2 h after the first oral intake, then to 713 m after 3 weeks, and finally to 1313 m in January 2017. OUTCOMES Recently, the patient is treated with Sildenafil 100 mg/d. He has no more pain during walking and his quality of life has improved. MAIN LESSONS TO LEARN Sildenafil, a PDE5i, may represent a new therapeutic option in addition to the conventional optimal medical therapy in patients with arterial claudication. tcpO2 measurement during exercise is a promising technique for the diagnosis and monitoring of patients with PAD. A crossover, double-blind, prospective randomized monocenter study (ARTERIOFIL-NCT02832570) and a double-blind prospective randomized multicenter study (VALSTAR-NCT02930811) are ongoing to confirm our original observation.
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Affiliation(s)
- Loukman Omarjee
- Vascular Investigations and Physiology Department, Angers University Hospital
- MitoVasc Institute, UMR CNRS 6015, INSERM U1083, Angers University, Angers, France
| | - Audrey Camarzana
- Vascular Investigations and Physiology Department, Angers University Hospital
| | - Samir Henni
- Vascular Investigations and Physiology Department, Angers University Hospital
- MitoVasc Institute, UMR CNRS 6015, INSERM U1083, Angers University, Angers, France
| | - Pierre Abraham
- Vascular Investigations and Physiology Department, Angers University Hospital
- MitoVasc Institute, UMR CNRS 6015, INSERM U1083, Angers University, Angers, France
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The maintenance ability and Ca 2+ availability of skeletal muscle are enhanced by sildenafil. Exp Mol Med 2016; 48:e278. [PMID: 27932789 PMCID: PMC5192075 DOI: 10.1038/emm.2016.134] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Revised: 09/08/2016] [Accepted: 09/22/2016] [Indexed: 12/23/2022] Open
Abstract
Sildenafil relaxes vascular smooth muscle cells and is used to treat pulmonary artery hypertension as well as erectile dysfunction. However, the effectiveness of sildenafil on skeletal muscle and the benefit of its clinical use have been controversial, and most studies focus primarily on tissues and organs from disease models without cellular examination. Here, the effects of sildenafil on skeletal muscle at the cellular level were examined using mouse primary skeletal myoblasts (the proliferative form of skeletal muscle stem cells) and myotubes, along with single-cell Ca2+ imaging experiments and cellular and biochemical studies. The proliferation of skeletal myoblasts was enhanced by sildenafil in a dose-independent manner. In skeletal myotubes, sildenafil enhanced the activity of ryanodine receptor 1, an internal Ca2+ channel, and Ca2+ movement that promotes skeletal muscle contraction, possibly due to an increase in the resting cytosolic Ca2+ level and a unique microscopic shape in the myotube membranes. Therefore, these results suggest that the maintenance ability of skeletal muscle mass and the contractility of skeletal muscle could be improved by sildenafil by enhancing the proliferation of skeletal myoblasts and increasing the Ca2+ availability of skeletal myotubes, respectively.
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Alexander MS, Gasperini MJ, Tsai PT, Gibbs DE, Spinazzola JM, Marshall JL, Feyder MJ, Pletcher MT, Chekler ELP, Morris CA, Sahin M, Harms JF, Schmidt CJ, Kleiman RJ, Kunkel LM. Reversal of neurobehavioral social deficits in dystrophic mice using inhibitors of phosphodiesterases PDE5A and PDE9A. Transl Psychiatry 2016; 6:e901. [PMID: 27676442 PMCID: PMC5048211 DOI: 10.1038/tp.2016.174] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 07/18/2016] [Indexed: 12/31/2022] Open
Abstract
Duchenne muscular dystrophy is caused by mutations in the DYSTROPHIN gene. Although primarily associated with muscle wasting, a significant portion of patients (approximately 25%) are also diagnosed with autism spectrum disorder. We describe social behavioral deficits in dystrophin-deficient mice and present evidence of cerebellar deficits in cGMP production. We demonstrate therapeutic potential for selective inhibitors of the cGMP-specific PDE5A and PDE9A enzymes to restore social behaviors in dystrophin-deficient mice.
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Affiliation(s)
- M S Alexander
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
- Departments of Pediatrics and Genetics, Harvard Medical School, Boston, MA, USA
- The Stem Cell Program, Boston Children's Hospital, Boston, MA, USA
| | - M J Gasperini
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - P T Tsai
- The F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - D E Gibbs
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - J M Spinazzola
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
- Departments of Pediatrics and Genetics, Harvard Medical School, Boston, MA, USA
| | - J L Marshall
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - M J Feyder
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
| | - M T Pletcher
- Rare Disease Research Unit, Pfizer, Cambridge, MA, USA
| | - E L P Chekler
- Rare Disease Research Unit, Pfizer, Cambridge, MA, USA
| | - C A Morris
- Rare Disease Research Unit, Pfizer, Cambridge, MA, USA
| | - M Sahin
- The F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - J F Harms
- Neuroscience Research Unit, Pfizer Global Research and Development, Cambridge, MA, USA
| | - C J Schmidt
- Neuroscience Research Unit, Pfizer Global Research and Development, Cambridge, MA, USA
| | - R J Kleiman
- The F.M. Kirby Neurobiology Center, Translational Neuroscience Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - L M Kunkel
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA
- Departments of Pediatrics and Genetics, Harvard Medical School, Boston, MA, USA
- The Stem Cell Program, Boston Children's Hospital, Boston, MA, USA
- The Manton Center for Orphan Diseases, Boston, MA, USA
- Harvard Stem Cell Institute, Cambridge, MA, USA
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Neff D, Kuhlenhoelter AM, Lin C, Wong BJ, Motaganahalli RL, Roseguini BT. Thermotherapy reduces blood pressure and circulating endothelin-1 concentration and enhances leg blood flow in patients with symptomatic peripheral artery disease. Am J Physiol Regul Integr Comp Physiol 2016; 311:R392-400. [PMID: 27335279 DOI: 10.1152/ajpregu.00147.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/15/2016] [Indexed: 11/22/2022]
Abstract
Leg thermotherapy (TT) application reduces blood pressure (BP) and increases both limb blood flow and circulating levels of anti-inflammatory mediators in healthy, young humans and animals. The purpose of the present study was to determine the impact of TT application using a water-circulating garment on leg and systemic hemodynamics and on the concentrations of circulating cytokines and vasoactive mediators in patients with symptomatic peripheral artery disease (PAD). Sixteen patients with PAD and intermittent claudication (age: 63 ± 9 yr) completed three experimental sessions in a randomized order: TT, control intervention, and one exercise testing session. The garment was perfused with 48°C water for 90 min in the TT session and with 33°C water in the control intervention. A subset of 10 patients also underwent a protocol for the measurement of blood flow in the popliteal artery during 90 min of TT using phase-contrast MRI. Compared with the control intervention, TT promoted a significant reduction in systolic (∼11 mmHg) and diastolic (∼6 mmHg) BP (P < 0.05) that persisted for nearly 2 h after the end of the treatment. The serum concentration of endothelin-1 (ET-1) was significantly lower 30 min after exposure to TT (Control: 2.3 ± 0.1 vs. TT: 1.9 ± 0.09 pg/ml, P = 0.026). In addition, TT induced a marked increase in peak blood flow velocity (∼68%), average velocity (∼76%), and average blood flow (∼102%) in the popliteal artery (P < 0.01). These findings indicate that TT is a practical and effective strategy to reduce BP and circulating ET-1 concentration and enhance leg blood flow in patients with PAD.
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Affiliation(s)
- Dustin Neff
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana
| | | | - Chen Lin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, Indiana
| | - Brett J Wong
- Department of Kinesiology and Health, Georgia State University, Atlanta, Georgia; and
| | | | - Bruno T Roseguini
- Department of Health and Kinesiology, Purdue University, West Lafayette, Indiana;
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13
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Evans RG. Oxygen regulation in biological systems. Am J Physiol Regul Integr Comp Physiol 2016; 310:R673-8. [PMID: 26911461 DOI: 10.1152/ajpregu.00004.2016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Accepted: 02/17/2016] [Indexed: 01/25/2023]
Affiliation(s)
- Roger G Evans
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, Melbourne, Australia
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14
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Ellis SS, Pepple DJ. Sildenafil Increases the p50 and Shifts the Oxygen-Hemoglobin Dissociation Curve to the Right. J Sex Med 2015; 12:2229-32. [PMID: 26553865 DOI: 10.1111/jsm.13038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Sildenafil (Viagra®) is a selective phosphodiesterase type 5 (PDE5) inhibitor that block the breakdown of cyclic guanyl monophosphate (cGMP) leading to relaxation of the smooth muscles of the corpus cavernous and an increase in blood flow resulting in penile erection. It is hypothesized that sildenafil will increase the release of oxygen from erythrocytes and shift the oxygen-hemoglobin curve to the right. AIM The aim of this study was to investigate the effect of varying doses of sildenafil on the p50 of the oxygen-hemoglobin dissociation curve in blood samples from eight (8) healthy adult male volunteers with normal hemoglobin HbAA. METHOD The hemox-analyzer was used to generate the p50 and the oxygen-hemoglobin dissociation curves. MAIN OUTCOME MEASURES The effect of different doses of sildenafil on the p50 values and shift of the oxygen-hemoglobin curve were the main outcome measures. RESULT Sildenafil caused a statistically significant increase in the p50 values and rightward shift of the oxygen-hemoglobin dissociation curve. CONCLUSION Sildenafil caused a dose-dependent increase in the release of oxygen from the erythrocytes as shown by the increased p50 values and rightward shift of the oxygen-hemoglobin dissociation curve. Ellis SS and Pepple DJ. Sildenafil increases the p50 and shifts the oxygen-hemoglobin dissociation curve to the right.
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Affiliation(s)
- Shantol Sastrice Ellis
- Department of Basic Medical Sciences, The University of the West Indies, Kingston, Jamaica
| | - Dagogo John Pepple
- Department of Basic Medical Sciences, The University of the West Indies, Kingston, Jamaica
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15
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Nyberg M, Piil P, Egelund J, Sprague RS, Mortensen SP, Hellsten Y. Potentiation of cGMP signaling increases oxygen delivery and oxidative metabolism in contracting skeletal muscle of older but not young humans. Physiol Rep 2015; 3:3/8/e12508. [PMID: 26272735 PMCID: PMC4562591 DOI: 10.14814/phy2.12508] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Aging is associated with progressive loss of cardiovascular and skeletal muscle function. The impairment in physical capacity with advancing age could be related to an insufficient peripheral O2 delivery to the exercising muscles. Furthermore, the mechanisms underlying an impaired blood flow regulation remain unresolved. Cyclic guanosine monophosphate (cGMP) is one of the main second messengers that mediate smooth muscle vasodilation and alterations in cGMP signaling could, therefore, be one mechanism by which skeletal muscle perfusion is impaired with advancing age. The current study aimed to evaluate the effect of inhibiting the main enzyme involved in cGMP degradation, phosphodiesterase 5 (PDE5), on blood flow and O2 delivery in contracting skeletal muscle of young and older humans. A group of young (23 ± 1 years) and a group of older (72 ± 2 years) male human subjects performed submaximal knee-extensor exercise in a control setting and following intake of the highly selective PDE5 inhibitor sildenafil. Sildenafil increased leg O2 delivery (6-9%) and leg O2 uptake (10-12%) at all three exercise intensities in older but not young subjects. The increase in leg O2 delivery with sildenafil in the older subjects correlated with the increase in leg O2 uptake (r (2) = 0.843). These findings suggest an insufficient O2 delivery to the contracting skeletal muscle of aged individuals and that reduced cGMP availability is a novel mechanism underlying impaired skeletal muscle perfusion with advancing age.
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Affiliation(s)
- Michael Nyberg
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Peter Piil
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Jon Egelund
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Randy S Sprague
- Department of Pharmacological and Physiological Science, Saint Louis, Missouri, USA
| | - Stefan P Mortensen
- Department of Cardiovascular and Renal Research, University of Southern Denmark, Odense, Denmark The Centre of Inflammation and Metabolism and the Centre for Physical Activity Research, Department of Infectious Diseases, Rigshospitalet University of Copenhagen, Copenhagen, Denmark
| | - Ylva Hellsten
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
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16
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Hiatt WR, Armstrong EJ, Larson CJ, Brass EP. Pathogenesis of the limb manifestations and exercise limitations in peripheral artery disease. Circ Res 2015; 116:1527-39. [PMID: 25908726 DOI: 10.1161/circresaha.116.303566] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Patients with peripheral artery disease have a marked reduction in exercise performance and daily ambulatory activity irrespective of their limb symptoms of classic or atypical claudication. This review will evaluate the multiple pathophysiologic mechanisms underlying the exercise impairment in peripheral artery disease based on an evaluation of the current literature and research performed by the authors. Peripheral artery disease results in atherosclerotic obstructions in the major conduit arteries supplying the lower extremities. This arterial disease process impairs the supply of oxygen and metabolic substrates needed to match the metabolic demand generated by active skeletal muscle during walking exercise. However, the hemodynamic impairment associated with the occlusive disease process does not fully account for the reduced exercise impairment, indicating that additional pathophysiologic mechanisms contribute to the limb manifestations. These mechanisms include a cascade of pathophysiological responses during exercise-induced ischemia and reperfusion at rest that are associated with endothelial dysfunction, oxidant stress, inflammation, and muscle metabolic abnormalities that provide opportunities for targeted therapeutic interventions to address the complex pathophysiology of the exercise impairment in peripheral artery disease.
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Affiliation(s)
- William R Hiatt
- From the Division of Cardiology, Department of Medicine (W.R.H., E.J.A.), CPC Clinical Research (W.R.H.), University of Colorado School of Medicine, Aurora; Cardiovascular & Metabolic Diseases Drug Discovery Unit, Takeda Pharmaceuticals, San Diego, CA (C.J.L.); and Department of Medicine, Harbor-UCLA Center for Clinical Pharmacology, Torrance, CA (E.P.B.).
| | - Ehrin J Armstrong
- From the Division of Cardiology, Department of Medicine (W.R.H., E.J.A.), CPC Clinical Research (W.R.H.), University of Colorado School of Medicine, Aurora; Cardiovascular & Metabolic Diseases Drug Discovery Unit, Takeda Pharmaceuticals, San Diego, CA (C.J.L.); and Department of Medicine, Harbor-UCLA Center for Clinical Pharmacology, Torrance, CA (E.P.B.)
| | - Christopher J Larson
- From the Division of Cardiology, Department of Medicine (W.R.H., E.J.A.), CPC Clinical Research (W.R.H.), University of Colorado School of Medicine, Aurora; Cardiovascular & Metabolic Diseases Drug Discovery Unit, Takeda Pharmaceuticals, San Diego, CA (C.J.L.); and Department of Medicine, Harbor-UCLA Center for Clinical Pharmacology, Torrance, CA (E.P.B.)
| | - Eric P Brass
- From the Division of Cardiology, Department of Medicine (W.R.H., E.J.A.), CPC Clinical Research (W.R.H.), University of Colorado School of Medicine, Aurora; Cardiovascular & Metabolic Diseases Drug Discovery Unit, Takeda Pharmaceuticals, San Diego, CA (C.J.L.); and Department of Medicine, Harbor-UCLA Center for Clinical Pharmacology, Torrance, CA (E.P.B.)
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17
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Efficacy of Sildenafil in a Patient With Restless Legs Syndrome/Willis-Ekbom Disease. Clin Neuropharmacol 2015; 38:67-8. [DOI: 10.1097/wnf.0000000000000072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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