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Hultman M, Richter F, Larsson M, Strömberg T, Iredahl F, Fredriksson I. Robust analysis of microcirculatory flowmotion during post-occlusive reactive hyperemia. Microvasc Res 2024; 155:104715. [PMID: 39004173 DOI: 10.1016/j.mvr.2024.104715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2024] [Revised: 07/01/2024] [Accepted: 07/11/2024] [Indexed: 07/16/2024]
Abstract
BACKGROUND Flowmotion analysis of the microcirculatory blood flow is a method to extract information about the vessel regulatory function. It has previously shown promise when applied to measurements during a post-occlusive reactive hyperemia. However, the reperfusion peak and the following monotonic decline introduces false low frequencies that should not be interpreted as rhythmic vasomotion effect. AIM To develop and validate a robust method for flowmotion analysis of post-occlusive reactive hyperemia signals. METHOD The occlusion-induced reperfusion response contains a typical rapid increase followed by a monotonic decline to baseline. A mathematical model is proposed to detrend this transient part of the signal to enable further flowmotion analysis. The model is validated in 96 measurements on healthy volunteers. RESULTS Applying the proposed model corrects the flowmotion signal without adding any substantial new false flowmotion components. CONCLUSION Future studies should use the proposed method or equivalent when analyzing flowmotion during post-occlusive reactive hyperemia to ensure valid results.
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Affiliation(s)
- Martin Hultman
- Department of Biomedical Engineering, Linköping University, Sweden; Perimed AB, Datavägen 9A, Järfälla, Stockholm, Sweden.
| | - Freya Richter
- Primary Health Care Center, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Marcus Larsson
- Department of Biomedical Engineering, Linköping University, Sweden
| | - Tomas Strömberg
- Department of Biomedical Engineering, Linköping University, Sweden
| | - Fredrik Iredahl
- Primary Health Care Center, Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Ingemar Fredriksson
- Department of Biomedical Engineering, Linköping University, Sweden; Perimed AB, Datavägen 9A, Järfälla, Stockholm, Sweden
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Goligorsky MS. Glomerular microcirculation: Implications for diabetes, preeclampsia, and kidney injury. Acta Physiol (Oxf) 2023; 239:e14048. [PMID: 37688412 PMCID: PMC10615779 DOI: 10.1111/apha.14048] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/28/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023]
Abstract
This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow. Multiple points of cooperation exist between autoregulatory and distributional mechanisms. Mutual interactions between myogenic and tubuloglomerular feedback (TGF) mechanisms regulating the inflow are briefly discussed. In addition to this, TGF operation involving purinergic, autocoid, and NO signaling affects, however, not only afferent arteriolar tone, but mesangial cell tone as well. The latter reversibly reconfigures the distribution of blood flow between the shorter and longer pathways in the glomerular tuft. I advance a hypothesis that blood flow in these pathways spontaneously alternates, and mesangial cell tonicity serves as a rheostatic shift between them. Furthermore, humoral messengers from macula densa cells, themselves dependent on myogenic mechanisms, fine-tune the secretion of renin and, subsequently, the local, intrarenal generation of angiotensin II, which, in turn, provides additional vasomotor signaling to glomerular capillaries through changing the tone of mesangial cells. This complex regulatory network may partially explain the phenomenon of renal functional reserve, as well as suggest implications for changes in renal function during pregnancy, early diabetes mellitus, and acute kidney injury.
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Affiliation(s)
- Michael S Goligorsky
- Department of Medicine, New York Medical College at the Touro University, Valhalla, New York, USA
- Department of Pharmacology, New York Medical College at the Touro University, Valhalla, New York, USA
- Department of Physiology, New York Medical College at the Touro University, Valhalla, New York, USA
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3
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Homes RAP, Giddens F, Francis RS, Hubbard RE, Gordon EH, Midwinter MJ. The sublingual microcirculation and frailty index in chronic kidney disease patients. Microcirculation 2023; 30:e12819. [PMID: 37285445 PMCID: PMC10909441 DOI: 10.1111/micc.12819] [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: 03/27/2023] [Revised: 05/18/2023] [Accepted: 05/25/2023] [Indexed: 06/09/2023]
Abstract
OBJECTIVE To examine the relationship between sublingual microcirculatory measures and frailty index in those attending a kidney transplant assessment clinic. METHODS Patients recruited had their sublingual microcirculation taken using sidestream dark field videomicroscopy (MicroScan, Micro Vision Medical, Amsterdam, the Netherlands) and their frailty index score using a validated short form via interview. RESULTS A total of 44 patients were recruited with two being excluded due to microcirculatory image quality scores exceeding 10. The frailty index score indicated significant correlations with total vessel density (p < .0001, r = -.56), microvascular flow index (p = .004, r = -.43), portion of perfused vessels (p = .0004, r = -.52), heterogeneity index (p = .015, r = .32), and perfused vessel density (p < .0001, r = -.66). No correlation was shown between the frailty index and age (p = .08, r = .27). CONCLUSIONS There is a relationship between the frailty index and microcirculatory health in those attending a kidney transplant assessment clinic, that is not confounded by age. These findings suggest that the impaired microcirculation may be an underlying cause of frailty.
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Affiliation(s)
- Ryan A. P. Homes
- School of Biomedical Science, Faculty of MedicineThe University of QueenslandBrisbaneQueenslandAustralia
| | - Fiona Giddens
- Centre for Health Services Research, Faulty of MedicineThe University of QueenslandBrisbaneQueenslandAustralia
| | - Ross S. Francis
- Department of NephrologyPrincess Alexandra HospitalBrisbaneQueenslandAustralia
- Faculty of MedicineThe University of QueenslandBrisbaneQueenslandAustralia
| | - Ruth E. Hubbard
- Centre for Health Services Research, Faulty of MedicineThe University of QueenslandBrisbaneQueenslandAustralia
| | - Emily H. Gordon
- Centre for Health Services Research, Faulty of MedicineThe University of QueenslandBrisbaneQueenslandAustralia
| | - Mark J. Midwinter
- School of Biomedical Science, Faculty of MedicineThe University of QueenslandBrisbaneQueenslandAustralia
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4
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Flowmotion imaging analysis of spatiotemporal variations in skin microcirculatory perfusion. Microvasc Res 2023; 146:104456. [PMID: 36403668 DOI: 10.1016/j.mvr.2022.104456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 11/02/2022] [Accepted: 11/12/2022] [Indexed: 11/19/2022]
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5
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Korolev AI, Fedorovich AA, Gorshkov AY, Dadaeva VA, Omelyanenko KV, Chashchin MG, Drapkina OM. Structural and functional state of various parts of skin microcirculation at an early stage of hypertension in working-age men. Microvasc Res 2023; 145:104440. [PMID: 36150473 DOI: 10.1016/j.mvr.2022.104440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/05/2022] [Accepted: 09/16/2022] [Indexed: 02/03/2023]
Abstract
STUDY PURPOSE To conduct a cross-sectional study on the structural and functional characteristics of various parts of skin microcirculation in working-age men with newly diagnosed hypertension (HTN). MATERIALS AND METHODS The study included 118 male participants (ages 30 to 60) who were not regularly taking any medicine, had no medical complaints, and subjectively considered themselves healthy at the time of study. All participants underwent a cross-sectional comprehensive medical examination. The following tests were performed: complete blood count, biochemical blood tests, video capillaroscopy (VCS), laser Doppler flowmetry (LDF) and photoplethysmography (PPG) on the left hand fingers, determination of flow-mediated vasodilation of the brachial artery, echocardiography, ultrasound of extracranial and femoral arteries, 24-h ambulatory blood pressure monitoring (ABPM). According to ABPM data, the participants were divided into two equal groups called a control group(CG) and a hypertension group(HG). There were 59 participants with normal BP in CG, and 59 participants with newly diagnosed HTN in HG. RESULTS Nailfold VCS of the ring finger revealed no significant differences between the groups at the level of exchange microvessels. According to LDF data, there was no decrease in tissue perfusion and signs of an increase in the activity of endothelial, neurogenic, and myogenic regulation of the tone of precapillary arterioles in the HTN group. According to PPG of the index finger, in contrast to CG, HTN participants had significantly higher values of the following parameters: normalized augmentation index (Alp75) - 3.8 % and - 5.25 % (p < 0.005), stiffness index (SI) - 7.6 m/s and 7.35 m/s (p < 0.05), reflection index (RI) - 36.5 % and 28.4 % (p < 0.005), respectively. DISCUSSION Working-age men in the early stage of HTN have neither capillary rarefaction nor an increase in the tone of skin precapillary arterioles. The largest contribution to peripheral vascular resistance in the onset of HTN is most likely made by large muscular arterioles, in which the neurogenic regulation of vascular tone predominates.
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Affiliation(s)
- A I Korolev
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia.
| | - A A Fedorovich
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia; Institute of Biomedical Problems, Russian Academy of Sciences, Khoroshyovskoe sh., 76, building 4, Moscow 123007, Russia
| | - A Yu Gorshkov
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia
| | - V A Dadaeva
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia; Peoples' Friendship University of Russia, Miklukho-Maklaya str., 6, Moscow 117198, Russia
| | - K V Omelyanenko
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia
| | - M G Chashchin
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia
| | - O M Drapkina
- National Medical Research Center for Therapy and Preventive Medicine, Petroverigsky per., 10, building 3, Moscow 101990, Russia
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El Miedany Y, Ismail S, Wadie M, Hassan M. Nailfold capillaroscopy: tips and challenges. Clin Rheumatol 2022; 41:3629-3640. [PMID: 36040673 DOI: 10.1007/s10067-022-06354-1] [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: 06/07/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 11/03/2022]
Abstract
Although nailfold capillaroscopy (NFC) appears to have a bright future in clinical practice, the lack of familiarity with the technique and how to interpret its outcomes is major barriers which have made nailfold capillaroscopy an underutilized method in standard clinical practice. Traditional methods for assessment and measurement of capillary patterns, density, and blood flow are falling behind and face some challenges. In fact, there have been calls for improvement, hence the recent publication of the standardization of NFC by the EULAR Study Group on Microcirculation in Rheumatic Diseases. Nailfold capillaroscopy has the advantage of being a non-invasive technique that provides a window into the digital microcirculation. This paved the way for a rapidly growing interest in using capillaroscopy parameters as outcome measures in research. In standard clinical practice, whilst its main application is in the identification of an underlying systemic sclerosis spectrum disorder in patients presenting with Raynaud's phenomenon, its use has expanded to include other clinical features possibly suggestive of an underlying connective tissue disease. This article presents the challenges, provides tips, and highlights the exciting potential of nailfold capillaroscopy in standard practice.
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Affiliation(s)
- Yasser El Miedany
- Canterbury Christ Church University, Institute of Medical Sciences, Canterbury, England, UK.
| | - Sherif Ismail
- Rheumatology and Rehabilitation, Internal Medicine Department, National Research Center, Cairo, Egypt
| | - Mary Wadie
- Internal Medicine Cairo University, Cairo, Egypt
| | - Mohammed Hassan
- Rheumatology and Rehabilitation, Tanta University, Tanta, Egypt
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7
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Fedorovich A, Loktionova Y, Zharkikh E, Gorshkov A, Korolev A, Dadaeva V, Drapkina O, Zherebtsov E. Skin microcirculation in middle-aged men with newly diagnosed arterial hypertension according to remote laser Doppler flowmetry data. Microvasc Res 2022; 144:104419. [DOI: 10.1016/j.mvr.2022.104419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 07/11/2022] [Accepted: 08/02/2022] [Indexed: 10/31/2022]
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8
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Effects of regular physical exercise on skin blood flow and cardiovascular risk factors in overweight and obese subjects. SCIENTIA MEDICA 2022. [DOI: 10.15448/1980-6108.2022.1.41980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Objective: it is well known that low omentin levels and reduced bioavailability of nitric oxide (NO) are outgrowth of obesity. Besides, in obese subjects, microvascular dysfunction can be an initial stage of cardiovascular diseases. This situation can be evaluated with skin laser–Doppler flowmetry (LDF).Methods: in this study we investigated the effects of 12 weeks moderate physical exercise on microvascular reactivity and plasma levels of omentin and NO in 25 overweight and obese subjects. Control group was composed of 28 sedentary participants who were neither obese nor overweight. Microvascular reactivity was handled by measurement of skin blood flow from the ring finger of the right hand with LDF, which is a non–invasive method for evaluation. With this method, it was aimed to examine the post–occlusive reactive hyperemia response of the patients. None of the participants in both groups have never followed a regular exercise schedule in their life span.Results: with regular exercise, there was a statistically significant decrease in glucose (p=0.008), cholesterol (p=0.05), and triglyceride (p=0.048) levels, while body mass index, high–density lipoprotein, and low–density lipoprotein levels did not change significantly in overweight/obese group. Also, the omentin level significantly increased (p=0.01), but NO level did not change significantly. Moreover, the amount of change in omentin and NO levels measured before and after the physical exercise were significantly correlated (r=0.57). Considering the microcirculation, rest flow (p=0.001) and peak flow value of LDF (p=0.001) increased after the physical exercise.Conclusion: our study shows that moderate physical exercise affects microvascular reactivity and plasma levels of omentin in overweight and obese subjects.
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Korolev AI, Fedorovich AA, Gorshkov AY, Dadaeva VA, Kim OT, Omelyanenko KV, Mikhaylova MA, Vasilyev DK, Dzhioeva ON, Akasheva DU, Drapkina OM. Parameters of cutaneous microvasculature in men of working age with newly diagnosed arterial hypertension. Clin Hemorheol Microcirc 2021; 80:373-387. [PMID: 34719487 DOI: 10.3233/ch-211292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To investigate structural and functional features of cutaneous microvasculature in men of working age with newly diagnosed arterial hypertension (AH). MATERIALS AND METHODS The study included 161 apparently healthy men from 30 to 60 years, who underwent a comprehensive examination of cardiovascular system "from the heart to the capillaries". Control group (CG) included 60 normotensive men. AH group included 101 men with elevated BP. RESULTS There is no rarefaction of the capillary bed and latent fluid retention in the interstitial space in the skin in men with AH. No data were obtained for increased endothelial, neurogenic and myogenic tone of resistive cutaneous precapillary arterioles in AH group, but a decrease in the perfusion efficiency of the endothelial and myogenic mechanisms of tissue perfusion modulation was noted. CONCLUSION Obtained results allow making the assumption that metabolic disorders at the level of capillaries that are of a systemic nature prevail in men with the onset of AH.
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Affiliation(s)
- A I Korolev
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - A A Fedorovich
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia.,FSBI SRC RF "Institute of Biomedical Problems" RAS, Moscow, Russia
| | - A Yu Gorshkov
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - V A Dadaeva
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - O T Kim
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - K V Omelyanenko
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - M A Mikhaylova
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - D K Vasilyev
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - O N Dzhioeva
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - D U Akasheva
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
| | - O M Drapkina
- FSBI "National Health and Research Center of Preventive Healthcare" of the Ministry of Health of Russia, Moscow, Russia
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10
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Theuerle JD, Al-Fiadh AH, Wong E, Patel SK, Ashraf G, Nguyen T, Wong TY, Ierino FL, Burrell LM, Farouque O. Retinal microvascular function predicts chronic kidney disease in patients with cardiovascular risk factors. Atherosclerosis 2021; 341:63-70. [PMID: 34756728 DOI: 10.1016/j.atherosclerosis.2021.10.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 09/27/2021] [Accepted: 10/13/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND AND AIMS Endothelial dysfunction is a precursor to atherosclerosis and is implicated in the coexistence between cardiovascular disease (CVD) and chronic kidney disease (CKD). We examined whether retinal microvascular dysfunction is present in subjects with renal impairment and predictive of long-term CKD progression in patients with CVD. METHODS In a single centre prospective observational study, 253 subjects with coronary artery disease and CVD risk factors underwent dynamic retinal vessel analysis. Retinal microvascular dysfunction was quantified by measuring retinal arteriolar and venular dilatation in response to flicker light stimulation. Serial renal function assessment was performed over a median period of 9.3 years using estimated GFR (eGFR). RESULTS Flicker light-induced retinal arteriolar dilatation (FI-RAD) was attenuated in patients with baseline eGFR <90 mL/min/1.73 m2, compared to those with normal renal function (eGFR ≥90 mL/min/1.73 m2) (1.0 [0.4-2.1]% vs. 2.0 [0.8-3.6]%; p < 0.01). In patients with normal renal function, subjects with the lowest FI-RAD responses exhibited the greatest annual decline in eGFR. In uni- and multivariable analysis, among subjects with normal renal function, a 1% decrease in FI-RAD was associated with an accelerated decline in eGFR of 0.10 (0.01, 0.15; p = 0.03) and 0.07 mL/min/1.73 m2 per year (0.00, 0.14; p = 0.06), respectively. FI-RAD was not predictive of CKD progression in subjects with baseline eGFR <90 mL/min/1.73 m2. CONCLUSIONS Retinal arteriolar endothelial dysfunction is present in patients with CVD who have early-stage CKD, and serves as an indicator of long-term CKD progression in those with normal renal function.
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Affiliation(s)
- James D Theuerle
- Department of Cardiology, Austin Health, Melbourne, Australia; Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Ali H Al-Fiadh
- Department of Cardiology, Austin Health, Melbourne, Australia; Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Edmond Wong
- Department of Cardiology, Austin Health, Melbourne, Australia
| | - Sheila K Patel
- Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Gizem Ashraf
- Department of Cardiology, Austin Health, Melbourne, Australia
| | - Thanh Nguyen
- The Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, Melbourne, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Duke-NUS Medical School, National University of Singapore, Singapore
| | | | - Louise M Burrell
- Department of Cardiology, Austin Health, Melbourne, Australia; Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia
| | - Omar Farouque
- Department of Cardiology, Austin Health, Melbourne, Australia; Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Australia.
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11
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Williams J, Gilchrist M, Strain WD, Fraser D, Shore A. An exploratory study of the relationship between systemic microcirculatory function and small solute transport in incident peritoneal dialysis patients. Perit Dial Int 2021; 42:513-521. [PMID: 34587842 DOI: 10.1177/08968608211047332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND The peritoneal capillary endothelium is widely considered to be the most influential structure in dictating the rate of small solute transport (SST) during peritoneal dialysis (PD). PD patients are at significant risk of systemic microcirculatory dysfunction. The relationship between peritoneal and systemic microcirculations in patients new to PD has not been well studied. We hypothesised that for patients on PD for less than 6 months, dysfunction in the systemic microcirculation would be reflected in the rate of SST. METHODS We recruited 29 patients to a cross-sectional, observational study. Rate of SST was measured using a standard peritoneal equilibration test. Laser Doppler Flowmetry was used to measure response to physical and pharmacological challenge (post-occlusive hyperaemic response and iontophoretic application of vasodilators) in the cutaneous microcirculation. Sidestream Darkfield imaging was used to assess sublingual microvascular density, flow and endothelial barrier properties. RESULTS We found no moderate or strong correlations between any of the measures of systemic microcirculatory function and rate of SST or albumin clearance. There was however a significant correlation between dialysate interleukin-6 concentrations and both SST (rs = 0.758 p ≤ 0.0001) and albumin clearance (rs = 0.53, p = 0.01). CONCLUSIONS In this study, systemic microvascular dysfunction did not significantly influence the rate of SST even early in patients PD careers. In conclusion, this study demonstrates that intraperitoneal factors particularly inflammation have a far greater impact on rate of SST than systemic factors.
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Affiliation(s)
- Jennifer Williams
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, UK
| | - Mark Gilchrist
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, UK
| | - William David Strain
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, UK
| | | | - Angela Shore
- Diabetes and Vascular Medicine Research Centre, NIHR Exeter Clinical Research Facility, University of Exeter College of Medicine and Health, UK
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12
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Theodorakopoulou MP, Dipla K, Zafeiridis A, Sarafidis P. Εndothelial and microvascular function in CKD: Evaluation methods and associations with outcomes. Eur J Clin Invest 2021; 51:e13557. [PMID: 33774823 DOI: 10.1111/eci.13557] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 02/19/2021] [Accepted: 03/14/2021] [Indexed: 12/29/2022]
Abstract
BACKGROUND Cardiovascular disease is the major cause of morbidity and mortality in patients with chronic kidney disease (CKD). Endothelial dysfunction, the hallmark of atherosclerosis, is suggested to be involved pathogenetically in cardiovascular and renal disease progression in these patients. METHODS This is a narrative review presenting the techniques and markers used for assessment of microvascular and endothelial function in patients with CKD and discussing findings of the relevant studies on the associations of endothelial dysfunction with co-morbid conditions and outcomes in this population. RESULTS Venous Occlusion Plethysmography was the first method to evaluate microvascular function; subsequently, several relevant techniques have been developed and used in patients with CKD, including brachial Flow-Mediated Dilatation, and more recently, Near-Infrared Spectroscopy and Laser Speckle Contrast Analysis. Furthermore, several circulating biomarkers are commonly used in clinical research. Studies assessing endothelial function using the above techniques and biomarkers suggest that endothelial dysfunction occurs early in CKD and contributes to the target organ damage, cardiovascular events, death and progression towards end-stage kidney disease. CONCLUSIONS Older and newer functional methods and several biomarkers have assessed endothelial dysfunction in CKD; accumulated evidence supports an association of endothelial dysfunction with outcomes. Future research with new, non-invasive and easily applicable methods could further delineate the role of endothelial dysfunction on cardiovascular and renal disease progression in patients with CKD.
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Affiliation(s)
- Marieta P Theodorakopoulou
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Konstantina Dipla
- Laboratory of Exercise Physiology and Biochemistry, Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Andreas Zafeiridis
- Laboratory of Exercise Physiology and Biochemistry, Department of Physical Education and Sports Science at Serres, Aristotle University of Thessaloniki, Serres, Greece
| | - Pantelis Sarafidis
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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13
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Andrade JM, Domínguez-Martín EM, Nicolai M, Faustino C, Rodrigues LM, Rijo P. Screening the dermatological potential of plectranthus species components: antioxidant and inhibitory capacities over elastase, collagenase and tyrosinase. J Enzyme Inhib Med Chem 2021; 36:257-269. [PMID: 33322969 PMCID: PMC7808741 DOI: 10.1080/14756366.2020.1862099] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A series of Plectranthus spp. plant extracts (aqueous, acetonic, methanolic and ethyl acetic) obtained from eight different species, and previously isolated compounds (ranging from polyphenols, diterpenes and triterpenes), were assayed for in vitro inhibition of the skin-related enzymes tyrosinase, collagenase and elastase, and for studying their antioxidant properties. The ethyl acetic extracts of P. grandidentatus and P. ecklonii registered the highest antioxidant activity, whereas acetonic, methanolic and ethyl acetic extracts of P. ecklonii, P. grandidentatus, P. madagascariensis and P. saccatus concerning the enzymatic inhibition assays revealed high anti-tyrosinase and anti-collagenase activities. From the isolated compounds tested, abietane diterpenes and triterpenes were highly active against tyrosinase and elastase activity. Overall, the experimental results showed the powerful antioxidant and inhibitory action on skin-related enzymes tyrosinase, collagenase and elastase of Plectranthus spp. extracts and/or isolated compounds, supporting their further research as bioactive metabolites against skin sagging and hyperpigmentation in cosmetic and pharmaceutical formulations.
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Affiliation(s)
- Joana M Andrade
- Research Center for Biosciences and Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, Lisboa, Portugal
| | - Eva María Domínguez-Martín
- Research Center for Biosciences and Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, Lisboa, Portugal.,Department of Biomedical Sciences, Faculty of Pharmacy, University of Alcalá, Madrid, Spain
| | - Marisa Nicolai
- Research Center for Biosciences and Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, Lisboa, Portugal
| | - Célia Faustino
- Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon (ULisboa), Lisbon, Portugal
| | - Luís Monteiro Rodrigues
- Research Center for Biosciences and Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, Lisboa, Portugal
| | - Patrícia Rijo
- Research Center for Biosciences and Health Technologies (CBIOS), Universidade Lusófona de Humanidades e Tecnologias, Lisboa, Portugal.,Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon (ULisboa), Lisbon, Portugal
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14
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Gemae MR, Akerman AP, McGarr GW, Meade RD, Notley SR, Schmidt MD, Rutherford MM, Kenny GP. Myths and methodologies: Reliability of forearm cutaneous vasodilatation measured using laser‐Doppler flowmetry during whole‐body passive heating. Exp Physiol 2020; 106:634-652. [DOI: 10.1113/ep089073] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 11/23/2020] [Indexed: 12/15/2022]
Affiliation(s)
- Mohamed R. Gemae
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Ashley P. Akerman
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Gregory W. McGarr
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Robert D. Meade
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Sean R. Notley
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Madison D. Schmidt
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Maura M. Rutherford
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
| | - Glen P. Kenny
- Human and Environmental Physiology Research Unit University of Ottawa Ottawa Ontario Canada
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15
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Theodorakopoulou MP, Schoina M, Sarafidis P. Assessment of Endothelial and Microvascular Function in CKD: Older and Newer Techniques, Associated Risk Factors, and Relations with Outcomes. Am J Nephrol 2020; 51:931-949. [PMID: 33311014 DOI: 10.1159/000512263] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/12/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Endothelium is the inner cellular lining of the vessels that modulates multiple biological processes including vasomotor tone, permeability, inflammatory responses, hemostasis, and angiogenesis. Endothelial dysfunction, the basis of atherosclerosis, is characterized by an imbalance between endothelium-derived relaxing factors and endothelium-derived contracting factors. SUMMARY Starting from the semi-invasive venous occlusion plethysmography, several functional techniques have been developed to evaluate microvascular function and subsequently used in patients with CKD. Flow-mediated dilatation of the forearm is considered to be the "gold standard," while in the last years, novel, noninvasive methods such as laser speckle contrast imaging and near-infrared spectroscopy are scarcely used. Moreover, several circulating biomarkers of endothelial function have been used in studies in CKD patients. This review summarizes available functional methods and biochemical markers for the assessment of endothelial and microvascular function in CKD and discusses existing evidence on their associations with comorbid conditions and outcomes in this population. Key Messages: Accumulated evidence suggests that endothelial dysfunction occurs early in CKD and is associated with target organ damage, progression of renal injury, cardiovascular events, and mortality. Novel methods evaluating microvascular function can offer a detailed, real-time assessment of underlying phenomena and should be increasingly used to shed more light on the role of endothelial dysfunction on cardiovascular and renal disease progression in CKD.
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Affiliation(s)
- Marieta P Theodorakopoulou
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Maria Schoina
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Pantelis Sarafidis
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece,
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16
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Alexandrou ME, Gkaliagkousi Ε, Loutradis C, Dimitriadis C, Mitsopoulos E, Lazaridis A, Nikolaidou B, Dolgiras P, Douma S, Papagianni A, Sarafidis PA. Haemodialysis and peritoneal dialysis patients have severely impaired post-occlusive skin forearm vasodilatory response assessed with laser speckle contrast imaging. Clin Kidney J 2020; 14:1419-1427. [PMID: 33959270 PMCID: PMC8087130 DOI: 10.1093/ckj/sfaa136] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Indexed: 12/15/2022] Open
Abstract
Background Endothelial dysfunction is associated with cardiovascular events and mortality in various disease states, including end-stage renal disease (ESRD). Novel technological approaches have emerged for real-time assessment of endothelial reactivity. This study examined skin microcirculation using laser speckle contrast imaging (LSCI) before and after arterial occlusion in ESRD patients undergoing haemodialysis (HD) or peritoneal dialysis (PD). Methods The 38 HD patients were matched in a 1:1 ratio with 38 PD patients (for age, sex and dialysis vintage) and 38 controls (for age and sex). Skin microvascular reactivity parameters assessed with LSCI included baseline perfusion, occlusion perfusion and peak perfusion during post-occlusive reactive hyperaemia (PORH); time to peak perfusion; proportional change from baseline to peak perfusion; baseline and peak cutaneous vascular conductance (CVC); proportional change from baseline to peak CVC and amplitude of the PORH response (i.e. the difference between peak and baseline CVC). Results Baseline perfusion [HD: 46.97 ± 14.6; PD: 49.32 ± 18.07; controls: 42.02 ± 11.94 laser specle perfusion units (LSPU), P = 0.097] and peak post-occlusion perfusion (104.77 ± 28.68 versus 109.04 ± 40.77 versus 116.96 ± 30.96 LSPU, P = 0.238) did not differ significantly between groups. However, the post-occlusive vascular response was completely different since the proportional increase from baseline to peak perfusion (HD: 133 ± 66; PD: 149 ± 125; controls: 187 ± 61%, P = 0.001) was significantly lower in ESRD patients and time to peak response was lower in HD but similar in PD patients compared with controls (HD: 7.24 ± 6.99; PD: 10.68 ± 9.45; controls: 11.11 ± 5.1 s, Kruskal–Wallis P = 0.003; pairwise comparisons: HD versus controls, P = 0.002; HD versus PD, P = 0.154; PD versus controls, P = 0.406). ESRD patients also had lower levels of peak CVC, indicating the maximum capillary recruitment (HD: 1.05 ± 0.3; PD: 1.07 ± 0.44; controls: 1.57 ± 0.52 LSPU/mmHg, P < 0.001), lower proportional increase of CVC at peak (P < 0.001) and lower amplitude of the PORH response, a measure of the difference between baseline and maximum capillary recruitment (P = 0.001). Conclusions Using this novel non-invasive technology, endothelial post-occlusive forearm skin vasodilatory response was found to be similar between HD and PD patients and significantly impaired compared with controls. Future studies are needed to assess the prognostic implications of this microcirculatory functional defect.
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Affiliation(s)
- Maria-Eleni Alexandrou
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece.,Department of Nephrology, Papageorgiou General Hospital, Thessaloniki, Greece
| | - Εugenia Gkaliagkousi
- 3rd Department of Internal Medicine, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Charalampos Loutradis
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Chrysostomos Dimitriadis
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Antonios Lazaridis
- 3rd Department of Internal Medicine, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Barbara Nikolaidou
- 3rd Department of Internal Medicine, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Panagiotis Dolgiras
- 3rd Department of Internal Medicine, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Stella Douma
- 3rd Department of Internal Medicine, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Aikaterini Papagianni
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Pantelis A Sarafidis
- Department of Nephrology, Hippokration Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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17
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Roumeliotis S, Mallamaci F, Zoccali C. Endothelial Dysfunction in Chronic Kidney Disease, from Biology to Clinical Outcomes: A 2020 Update. J Clin Med 2020; 9:jcm9082359. [PMID: 32718053 PMCID: PMC7465707 DOI: 10.3390/jcm9082359] [Citation(s) in RCA: 115] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/20/2020] [Accepted: 07/21/2020] [Indexed: 02/06/2023] Open
Abstract
The vascular endothelium is a dynamic, functionally complex organ, modulating multiple biological processes, including vascular tone and permeability, inflammatory responses, thrombosis, and angiogenesis. Endothelial dysfunction is a threat to the integrity of the vascular system, and it is pivotal in the pathogenesis of atherosclerosis and cardiovascular disease. Reduced nitric oxide (NO) bioavailability is a hallmark of chronic kidney disease (CKD), with this disturbance being almost universal in patients who reach the most advanced phase of CKD, end-stage kidney disease (ESKD). Low NO bioavailability in CKD depends on several mechanisms affecting the expression and the activity of endothelial NO synthase (eNOS). Accumulation of endogenous inhibitors of eNOS, inflammation and oxidative stress, advanced glycosylation products (AGEs), bone mineral balance disorders encompassing hyperphosphatemia, high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23), and low levels of the active form of vitamin D (1,25 vitamin D) and the anti-ageing vasculoprotective factor Klotho all impinge upon NO bioavailability and are critical to endothelial dysfunction in CKD. Wide-ranging multivariate interventions are needed to counter endothelial dysfunction in CKD, an alteration triggering arterial disease and cardiovascular complications in this high-risk population.
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Affiliation(s)
- Stefanos Roumeliotis
- Division of Nephrology and Hypertension, 1st Department of Internal Medicine, School of Medicine, AHEPA Hospital, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece;
| | - Francesca Mallamaci
- CNR-IFC (National Research Council of Italy, Centre of Clinical Physiology, Clinical Epidemiology of Renal Diseases and Hypertension Unit, Reggio Cal., c/o Ospedali Riuniti, 89124 Reggio Cal, Italy;
| | - Carmine Zoccali
- CNR-IFC (National Research Council of Italy, Centre of Clinical Physiology, Clinical Epidemiology of Renal Diseases and Hypertension Unit, Reggio Cal., c/o Ospedali Riuniti, 89124 Reggio Cal, Italy;
- Correspondence: ; Tel.: +39-340-73540-62
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18
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Mottard N, Berkowitz DE, Santhanam L. Assessing Renal Microvascular Reactivity by Laser Speckle-Contrast Imaging in Angiotensin-II-Treated Mice. Int J Nephrol Renovasc Dis 2020; 13:45-51. [PMID: 32273746 PMCID: PMC7108873 DOI: 10.2147/ijnrd.s240147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 03/09/2020] [Indexed: 12/13/2022] Open
Abstract
Introduction The kidney is one of the main organs affected by microvascular damage wrought by hypertension. We developed an approach to investigate renal microcirculatory disturbance in live mice by measuring post-occlusive reactive hyperemia (PORH), a reactivity test exploring endothelial and neuro-microvascular functioning. Laser speckle-contrast analysis (LASCA) assesses microvascular blood flow; it provides real-time images of spatial and temporal blood flow dynamics. We compared basal blood flow and PORH test between control and angiotensin-II-treated mice (Ang-II) to validate the model. Objective The study objective was to develop an approach to investigate renal microcirculation, and then to compare microvascular reactivity assessed on LASCA in control versus Ang-II mice. Methods Thirty 7-week-old wild-type C57BL/6J mice were allocated into two groups. One received angiotensin-II via osmotic minipumps (Ang-II; n=15); the other served as control (n=15). Basal blood flow was measured on LASCA. The PORH test was then performed in the two groups. Results Control mice had significantly lower basal renal microcirculatory flow, expressed in perfusion units (PU), than Ang-II-treated mice (1448 ± 96 vs 1703 ± 185 PU, respectively; P < 0.05). Peak flow was lower in controls than in Ang-II mice (1617±104 vs.1724 ± 205 PU, respectively; P=0.21). Control mice had significantly higher kidney PORH than Ang-II mice (8±3 vs 1±4%, respectively; P < 0.05). Conclusion We developed an innovative technique to study renal microcirculation in mice. Ang-II-treated mice showed significantly higher basal blood flow than controls, while PORH was significantly higher in controls than in Ang-II mice.
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Affiliation(s)
- Nicolas Mottard
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Anesthesiology and Critical Care, Clinique de la Sauvegarde, Ramsay Santé, Lyon, France
| | - Dan E Berkowitz
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
| | - Lakshmi Santhanam
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
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19
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Fabregate-Fuente M, Arbeitman CR, Cymberknop LJ, Bara-Ledesma N, Arriazu-Galindo M, Martin-Fernandez L, Armentano RL, Saban-Ruiz J. Characterization of Microvascular Post Occlusive Hyperemia Using Laser Doppler Flowmetry Technique in Subjects With Cardiometabolic Disorders. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2019:514-517. [PMID: 31945950 DOI: 10.1109/embc.2019.8856623] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
INTRODUCTION Laser Doppler flowmetry (LDF) provides a noninvasive real-time quantification of relative changes in cutaneous perfusion. Assessment of the microvascular function can provide information on the development of various cardiometabolic disorders. In recent years, non-invasive measurements have gain attention, due to the potential complications associated to invasive procedures. OBJECTIVE To differentiate the microvascular function between subjects with cardiometabolic disorders and healthy controls. METHODS Evaluation through LDF during post-occlusive reactive hyperemia (PORH) in patients with or without history of cardiometabolic disorders. RESULTS Peak values of microvascular flow during post-occlusive reactive hyperemia and both upload and recovery slopes were lesser in the pathological group. CONCLUSION A novel approach to characterize LDF during PORH was useful to differentiate patients with cardiometabolic disorders from healthy subjects.
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20
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Williams J, Gilchrist M, Strain D, Fraser D, Shore A. The systemic microcirculation in dialysis populations. Microcirculation 2020; 27:e12613. [PMID: 32065681 DOI: 10.1111/micc.12613] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/08/2020] [Accepted: 02/14/2020] [Indexed: 12/17/2022]
Abstract
In a rapidly expanding population of patients with chronic kidney disease, including 2 million people requiring renal replacement therapy, cardiovascular mortality is 15 times greater than the general population. In addition to traditional cardiovascular risk factors, more poorly defined risks related to uremia and its treatments appear to contribute to this exaggerated risk. In this context, the microcirculation may play an important early role in cardiovascular disease associated with chronic kidney disease. Experimentally, the uremic environment and dialysis have been linked to multiple pathways causing microvascular dysfunction. Coronary microvascular dysfunction is reflected in remote and more easily studied vascular beds such as the skin. There is increasing evidence for a correlation between systemic microvascular dysfunction and adverse cardiovascular outcomes. Systemic microcirculatory changes have not been extensively investigated across the spectrum of chronic kidney disease. Recent advances in non-invasive techniques studying the microcirculation in vivo in man are increasing the data available particularly in patients on hemodialysis. Here, we review current knowledge of the systemic microcirculation in dialysis populations, explore whether non-invasive techniques to study its function could be used to detect early stage cardiovascular disease, address challenges faced in studying this patient cohort and identify potential future avenues for research.
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Affiliation(s)
- Jennifer Williams
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK.,NIHR Exeter Clinical Research Facility, Royal Devon and Exeter Foundation NHS Trust, Exeter, UK
| | - Mark Gilchrist
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK.,NIHR Exeter Clinical Research Facility, Royal Devon and Exeter Foundation NHS Trust, Exeter, UK
| | - David Strain
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK.,NIHR Exeter Clinical Research Facility, Royal Devon and Exeter Foundation NHS Trust, Exeter, UK
| | - Donald Fraser
- Wales Kidney Research Unit, Cardiff University, Cardiff, UK
| | - Angela Shore
- Diabetes and Vascular Medicine Research Centre, Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter, UK.,NIHR Exeter Clinical Research Facility, Royal Devon and Exeter Foundation NHS Trust, Exeter, UK
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21
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Effects of hemodialysis on blood volume, macro- and microvascular function. Microvasc Res 2019; 129:103958. [PMID: 31734376 DOI: 10.1016/j.mvr.2019.103958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 11/11/2019] [Accepted: 11/13/2019] [Indexed: 11/24/2022]
Abstract
BACKGROUND Vascular dysfunction is considered to spur the progression of cardiovascular disease in hemodialysis (HD) patients. Whether the HD procedure itself contributes to vascular dysfunction remains incompletely investigated. The present study sought to comprehensively assess the effects of HD on arterial and venous function along with concomitant changes in blood volume (BV). METHODS AND RESULTS We determined BV with high-precision, automated carbon monoxide-rebreathing, arterial stiffness using applanation tonometry and intrinsic microvascular function via retinal vessel analysis prior to and after conventional 4-hour HD in fasting-controlled conditions in 10 patients. All HD patients were non-smokers and non-obese (body mass index = 22.8 ± 2.8 m·kg-2). Hypertension (70%), coronary artery disease (40%) and diabetes mellitus (20%) were the most prevalent comorbidities. Prior to HD, all patients presented with hypervolemia (+2208 ± 1213 ml). HD decreased body weight (-1.72 ± 1.25 kg, P = 0.002) and plasma volume (-689 ± 566 ml, P = 0.004), while hematocrit (Hct) was concomitantly increased (+4.8 ± 4.5%, P = 0.009). HD did not affect large elastic artery stiffness, as determined by carotid-femoral pulse wave velocity (P = 0.448) and carotid distensibility (P = 0.562). In contrast, flicker light-induced retinal venular dilation was reduced by three-fourths after HD (-2.4 ± 1.7%, P = 0.039), in parallel to increased retinal venular diameter (+11.2 ± 4.9 μm, P = 0.002). In regression analyses, a negative association was observed between HD-induced changes in Hct and retinal venular dilation (r ≥ -0.89, P ≤ 0.045). CONCLUSION Conventional HD resulting in substantial plasma volume removal do not alter large artery elastic properties, whereas intrinsic microvascular venular dilator function is markedly impaired, an effect directly associated with the increase in hemoconcentration.
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22
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Ministrini S, Fattori C, Ricci MA, Bianconi V, Paltriccia R, Boni M, Paganelli MT, Vaudo G, Lupattelli G, Pasqualini L. Microcirculatory Improvement Induced by Laparoscopic Sleeve Gastrectomy Is Related to Insulin Sensitivity Retrieval. Obes Surg 2019; 28:3151-3158. [PMID: 29752665 DOI: 10.1007/s11695-018-3290-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
AIMS Microvascular dysfunction is a potential factor explaining the association of obesity, insulin resistance, and vascular damage in morbidly obese subjects. The purpose of the study was to evaluate possible determinants of microcirculatory improvement 1 year after laparoscopic sleeve gastrectomy (LSG) intervention. METHODS Thirty-seven morbidly obese subjects eligible for bariatric surgery were included in the study. Post-occlusive reactive hyperemia (PORH) of the forearm skin was measured as area of hyperemia (AH) by laser-Doppler flowmetry before LSG and after a 1-year follow-up. RESULTS After intervention, we observed a significant reduction in BMI, HOMA index, HbA1c, and a significant increase of AH in all patients after surgery; this variation was significant only in those patients having insulin resistance or prediabetes/diabetes. Although significant correlation between the increase of AH and the reduction of both BMI, HOMA index, and HbA1c was observed, BMI was the only independent predictor of AH variation after LSG at the linear regression analysis. CONCLUSIONS Our study shows that LSG intervention is correlated with a significant improvement in the microvascular function of morbidly obese subjects; this improvement seems to be related to the baseline degree of insulin-resistance and to the retrieval of insulin-sensitivity post-intervention.
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Affiliation(s)
- Stefano Ministrini
- Department of Medicine, Università degli Studi di Perugia, Perugia, Italy.
| | - Chiara Fattori
- Department of Medicine, Università degli Studi di Perugia, Perugia, Italy
| | | | - Vanessa Bianconi
- Department of Medicine, Università degli Studi di Perugia, Perugia, Italy
| | - Rita Paltriccia
- Department of Medicine, Università degli Studi di Perugia, Perugia, Italy
| | - Marcello Boni
- General Surgery, ASL Umbria2, "S.Giovanni Battista" Hospital, Foligno, PG, Italy
| | | | - Gaetano Vaudo
- Department of Medicine, Università degli Studi di Perugia, Perugia, Italy
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Du Y, Taylor CG, Zahradka P. Modulation of endothelial cell responses and vascular function by dietary fatty acids. Nutr Rev 2019; 77:614-629. [PMID: 31228246 DOI: 10.1093/nutrit/nuz026] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023] Open
Abstract
Healthy and functional endothelial cells play important roles in maintaining vascular homeostasis, whereas endothelial dysfunction initiates and exacerbates vascular disease progression. Interventional studies with dietary fatty acids have shown that these molecules have varying effects on vascular function. It is hypothesized that the actions of dietary fatty acids on vascular function may be mediated in part through endothelial cells. This review summarizes the results of studies that have examined the acute and chronic effects of dietary fatty acids on endothelial function and vascular properties in humans, as well as the potential mechanisms by which n-3 polyunsaturated fatty acids regulate endothelial function. Altogether, this article provides an extensive review of how fatty acids contribute to vascular function through their ability to modulate endothelial cells and discusses relationships between dietary fatty acids and endothelial cells in the context of vascular dysfunction.
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Affiliation(s)
- Youjia Du
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Carla G Taylor
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
| | - Peter Zahradka
- Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Food and Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Canadian Centre for Agri-Food Research in Health and Medicine, St Boniface Albrechtsen Research Centre, Winnipeg, Manitoba, Canada
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24
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Martini R, Bagno A. The wavelet analysis for the assessment of microvascular function with the laser Doppler fluxmetry over the last 20 years. Looking for hidden informations. Clin Hemorheol Microcirc 2018; 70:213-229. [DOI: 10.3233/ch-189903] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Romeo Martini
- Department of Cardio-Thorax and Vascular Sciences, Unit of Angiology, Azienda Ospedaliera Universitaria di Padova, Italy
| | - Andrea Bagno
- Department of Industrial Engineering, Università di Padova, Italy
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25
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Sebzda KN, Kuczmarski AV, Pohlig RT, Lennon SL, Edwards DG, Wenner MM. Ovarian hormones modulate endothelin-1 receptor responses in young women. Microcirculation 2018; 25:e12490. [PMID: 29999581 DOI: 10.1111/micc.12490] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/30/2018] [Accepted: 07/10/2018] [Indexed: 12/16/2022]
Abstract
OBJECTIVE We recently demonstrated ETBR mediate vasodilation in young but not postmenopausal women; it is unclear if this is related to age or a decline in ovarian hormones. The purpose of this study was to test the hypothesis that ETBR responses are modulated by ovarian hormones. METHODS We measured cutaneous vasodilatory responses in 12 young women (22 ± 1 years, 23 ± 1 kg/m2 ) during the ML (days 20-25) and EF (days 2-5) phases of the menstrual cycle. Cutaneous microdialysis perfusions of lactated Ringer (control), ETBR antagonist (BQ-788, 300 nmol/L), and ETAR antagonist (BQ-123, 500 nmol/L) were performed, followed by local heating to 42°C. RESULTS Serum estradiol (ML: 118 ± 16 vs EF: 44 ± 9 pg/mL, P < 0.05) and progesterone (ML: 8.3 ± 1.0 vs EF: 0.7 ± 0.2 ng/mL, P < 0.05) were higher during ML vs EF phase. ETBR blockade decreased vasodilation during ML (control: 91 ± 2 vs BQ-788: 83 ± 2%CVCmax, P < 0.05) but not EF (control: 89 ± 2 vs BQ-788: 89 ± 1%CVCmax). ETAR blockade also decreased vasodilation during ML (control: 91 ± 2 vs BQ-123: 87 ± 2%CVCmax, P < 0.05) but not EF (control: 89 ± 2 vs BQ-123: 92 ± 2%CVCmax). CONCLUSIONS These data suggest that fluctuations in ovarian hormones modulate ETBR and ETAR responses in young women.
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Affiliation(s)
- Kelly N Sebzda
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Andrew V Kuczmarski
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Ryan T Pohlig
- Biostatistic Core Facility, College of Health Sciences, University of Delaware, Newark, Delaware
| | - Shannon L Lennon
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Megan M Wenner
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
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26
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Ugenti V, Romano AC, Tibirica E. Microvascular endothelial dysfunction during cardiopulmonary bypass in surgery for correction of cyanotic and acyanotic congenital heart disease. Microvasc Res 2018; 120:55-58. [PMID: 29958862 DOI: 10.1016/j.mvr.2018.06.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/08/2018] [Accepted: 06/25/2018] [Indexed: 11/19/2022]
Abstract
OBJECTIVE To evaluate endothelium-dependent microvascular reactivity during cardiopulmonary bypass (CPB) in surgery for the correction of cyanotic and acyanotic congenital heart disease (CHD) in children and infants using laser Doppler perfusion monitoring (LDPM). METHODS This cross-sectional observational study included one hundred consecutive acyanotic (AC, n = 61) and cyanotic (C, n = 39) pediatric patients scheduled for cardiac surgery for correction of CHD. The endothelium-dependent microvascular vasodilation of the skin of the forehead was evaluated using a single-point LDPM coupled with local thermal hyperemia (LTH). RESULTS LTH induced significant increases in microvascular conductance both in AC and C patients after the induction of anesthesia, during CPB and after weaning from CPB. Nevertheless, the vasodilation induced by LTH was significantly blunted during CPB when compared with values obtained after the induction of anesthesia both in AC and C patients. Microvascular endothelial reactivity nearly normalized after the discontinuation of CPB. CONCLUSION The evaluation of systemic microvascular reactivity on the forehead skin of infants and children using LDPM appears to be a valuable tool for optimizing microvascular perfusion during CPB in pediatric cardiac surgery.
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Affiliation(s)
- Viviana Ugenti
- National Institute of Cardiology, Rio de Janeiro, Brazil
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Yuan X, Wu Q, Shang F, Li B, Liu M, Wang B, Sheng Y, Zhang H, Xiu R. A comparison of the cutaneous microvascular properties of the Spontaneously Hypertensive and the Wistar-Kyoto rats by Spectral analysis of Laser Doppler. Clin Exp Hypertens 2018; 41:342-352. [PMID: 29939761 DOI: 10.1080/10641963.2018.1481424] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
This work was aimed to study skin blood perfusion, vasomotion and vascular responses of the Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) in different stages of age using spectral. Laser-Doppler flowmetry (LDF) was used to examine the ears and limbs of WKY (12 and 48 weeks old) and SHR (12 and 48 weeks old). The skin blood flow oscillations (SBFOs) were studied by wavelet spectral analysis of LDF tracings. Then, we observed that old groups showed decreased perfusion and SBFO in the ears of both SHR and WKY. The SHR showed obviously lower postocclusive reactive hypera (PORH) ratio at the same age. A decreased peak-time occurred in the SHR of old age group. After PORH test, a statistically significant increase was observed within all subintervals in the absolute amplitude of 12-week WKY and only within IV and III subintervals in the absolute amplitude of 12-week SHR. But, the absolute amplitude of 48-week WKY and SHR showed no statistically significant increase within all subintervals. Results indicated that local regulating function of peripheral vascular was impaired in rat with hypertension and aging. Abbreviations LDF: Laser-Doppler flowmetry; SBF: Skin blood flow; SBFO: Skin blood flow oscillation; PORH: Postocclusive reactive hyperemia; SHR: Spontaneously hypertensive rats; WKY: Wistar-Kyoto rats; LDF: Laser-Doppler flowmetry; LDI: Laser Doppler Imaging; BP: Blood pressure.
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Affiliation(s)
- Xiaochen Yuan
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Qingbin Wu
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Fei Shang
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Bingwei Li
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Mingming Liu
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Bing Wang
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Youming Sheng
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Honggang Zhang
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
| | - Ruijuan Xiu
- a Key Laboratory for Microcirculation , Ministry of Health.,b Institute of Microcirculation , Chinese Academy Medical Sciences & Pecking Union Medical College , Beijing , China
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Craighead DH, Smith CJ, Alexander LM. Blood pressure normalization via pharmacotherapy improves cutaneous microvascular function through NO-dependent and NO-independent mechanisms. Microcirculation 2018; 24. [PMID: 28510986 DOI: 10.1111/micc.12382] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 05/11/2017] [Indexed: 12/20/2022]
Abstract
Hypertension is associated with endothelial dysfunction and vascular remodeling. OBJECTIVE To assess effects of antihypertensive pharmacotherapy on eNOS- and iNOS-dependent mechanisms and maximal vasodilator capacity in the cutaneous microvasculature. METHODS Intradermal microdialysis fibers were placed in 15 normotensive (SBP 111±2 mm Hg), 12 unmedicated hypertensive (SBP 142±2 mm Hg), and 12 medicated hypertensive (SBP 120±2 mm Hg) subjects. Treatments were control, iNOS-inhibited (1400w), and NOS-inhibited (l-NAME). Red cell flux, measured during local heating (42°C) and ACh dose-response protocols, was normalized to CVC (flux MAP-1 ) and a percentage of maximal vasodilation (%CVCmax ). RESULTS Compared to normotensives, ACh-mediated vasodilation was attenuated in the hypertensive (P<.001), but not in medicated subjects (P=.83). NOS inhibition attenuated ACh-mediated vasodilation in normotensives compared to hypertensive (P<.001) and medicated (P<.001) subjects. With iNOS inhibition, there was no difference in ACh-mediated vasodilation between groups. Compared to the normotensives, local heat-induced vasodilation was attenuated in the hypertensives (P<.001), but iNOS inhibition augmented vasodilation in the hypertensives so this attenuation was abolished (P=.31). Compared to normotensives, maximal vasodilator capacity was reduced in the hypertensive (P=.014) and medicated subjects (P=.004). CONCLUSIONS In the cutaneous microvasculature, antihypertensive pharmacotherapy improved endothelial function through NO-dependent and NO-independent mechanisms, but did not improve maximal vasodilator capacity.
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Affiliation(s)
- Daniel H Craighead
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
| | - Caroline J Smith
- Department of Health & Exercise Science, Appalachian State University, Boone, NC, USA
| | - Lacy M Alexander
- Department of Kinesiology, The Pennsylvania State University, University Park, PA, USA
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Bagno A, Martini R. Bridging the gap between basic research on microcirculation and clinical world: The translational marriage between engineering and medicine. Clin Hemorheol Microcirc 2018; 71:357-363. [PMID: 29865047 DOI: 10.3233/ch-180415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The words "Translational" and "Medicine" have been recently coupled to indicate a combination of disciplines, resources, expertise, and techniques aimed at enhancing prevention, diagnosis, and therapies. As stated in 2015 by the European Society for Translational Medicine, translational medicine is "an interdisciplinary branch of the biomedical field supported by three main pillars: benchside, bedside and community". By definition, Translational Medicine is a highly interdisciplinary field, which gathers several specialties aimed at improving the global healthcare system.With regard to the assessment of the microcirculatory function, it is worthwhile to mention the growing interest from both basic research and clinical practice. Microcirculation is where the exchange of substances between blood and tissues takes place. Thus, it plays a key role in the pathophysiology of many diseases. Nonetheless, a gap does exist between the theoretical analysis of the microcirculatory function and its clinical exploitation. This gap can be due to the weak dissemination of analytical methods and theoretical results within the clinical community, which also delays the establishment of specific operative guidelines.This paper aims at encouraging, and possibly accelerating, the translation of basic research outcomes on microcirculatory function assessment into clinical applications.
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Affiliation(s)
- Andrea Bagno
- Department of Industrial Engineering, University of Padova, Padova, Italy
| | - Romeo Martini
- UOC of Angiology, Azienda Ospedale Università di Padova, Padova, Italy
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Zhang X, Low S, Ang K, Yeoh LY, Tavintharan S, Sum CF, Lim SC. Microvascular endothelial function is an independent predictor for albuminuria progression among Asians with type 2 diabetes-A prospective cohort study. Microcirculation 2018; 25:e12453. [PMID: 29602193 DOI: 10.1111/micc.12453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 03/21/2018] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We aim to investigate whether microvascular endothelial dysfunction is an independent predictor for future albuminuria progression in T2DM cohort. METHODS A total of 1098 patients with T2DM were clinically assessed at baseline and 3.2-year follow-up. Progression was defined as transition from normoalbuminuria (ACR <30 mg/g) to microalbuminuria (ACR = 30-299 mg/g) or macroalbuminuria (ACR >300 mg/g), or microalbuminuria to macroalbuminuria. Microvascular endothelial vasodilation at baseline was quantified using LDF. The increase in perfusion in response to ACh and NaNP was calculated. Logistic regression model was used to estimate the OR for albuminuria progression. RESULTS Albuminuria progression occurred in 226 (20.6%) patients. Baseline ACh was significantly higher in nonprogression than progression group (80.0 ± 53.2% vs 72.0 ± 49.7%, P = .04). There is no significant difference in NaNP between the two groups (111.1 ± 80.3% vs 121.1 ± 87.4%, P = .12). After multivariable adjustment, 1-SD increase in ACh was marginally associated with albuminuria progression (OR = 0.87, 95% CI, 0.72-1.02, P = .08) in all patients. When stratified by baseline albuminuria, 1-SD increase in ACh was significantly associated with albuminuria progression in normoalbuminuria (OR = 0.76, 95% CI, 0.59-0.97, P = .03), but not in microalbuminuria patients (OR = 1.18, 95% CI, 0.81-1.70, P = .39). CONCLUSIONS Impaired endothelial-dependent microvascular reactivity predicts the onset of albuminuria progression among T2DM patients with normoalbuminuria.
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Affiliation(s)
- Xiao Zhang
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Serena Low
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Keven Ang
- Clinical Research Unit, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Lee Ying Yeoh
- Department of Medicine, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Subramaniam Tavintharan
- Department of Medicine, Khoo Teck Puat Hospital, Singapore, Singapore.,Diabetes Centre, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Chee Fang Sum
- Department of Medicine, Khoo Teck Puat Hospital, Singapore, Singapore.,Diabetes Centre, Khoo Teck Puat Hospital, Singapore, Singapore
| | - Su Chi Lim
- Department of Medicine, Khoo Teck Puat Hospital, Singapore, Singapore.,Diabetes Centre, Khoo Teck Puat Hospital, Singapore, Singapore.,Saw Swee Hock School of Public Health, National University of Singapore, Singapore, Singapore
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Kirkman DL, Muth BJ, Ramick MG, Townsend RR, Edwards DG. Role of mitochondria-derived reactive oxygen species in microvascular dysfunction in chronic kidney disease. Am J Physiol Renal Physiol 2017; 314:F423-F429. [PMID: 29117995 DOI: 10.1152/ajprenal.00321.2017] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cardiovascular disease is the leading cause of mortality in chronic kidney disease (CKD). Mitochondrial dysfunction secondary to CKD is a potential source of oxidative stress that may impair vascular function. This study sought to determine if mitochondria-derived reactive oxygen species contribute to microvascular dysfunction in stage 3-5 CKD. Cutaneous vasodilation in response to local heating was assessed in 20 CKD patients [60 ± 13 yr; estimated glomerular filtration rate (eGFR) 46 ± 13 ml·kg-1·1.73 m-2] and 11 matched healthy participants (58 ± 2 yr; eGFR >90 ml·kg-1·1.73 m-2). Participants were instrumented with two microdialysis fibers for the delivery of 1) Ringer solution, and 2) the mitochondria- specific superoxide scavenger MitoTempo. Skin blood flow was measured via laser Doppler flowmetry during standardized local heating (42°C). Cutaneous vascular conductance (CVC) was calculated as a percentage of the maximum conductance achieved with sodium nitroprusside infusion at 43°C. Urinary isofuran/F2-isoprostane ratios were assessed by gas-chromatography mass spectroscopy. Isofuran-to-F2-isoprostane ratios were increased in CKD patients (3.08 ± 0.32 vs. 1.69 ± 0.12 arbitrary units; P < 0.01) indicative of mitochondria-derived oxidative stress. Cutaneous vasodilation was impaired in CKD compared with healthy controls (87 ± 1 vs. 92 ± 1%CVCmax; P < 0.01). Infusion of MitoTempo significantly increased the plateau phase CVC in CKD patients (CKD Ringer vs. CKD MitoTempo: 87 ± 1 vs. 93 ± 1%CVCmax; P < 0.01) to similar levels observed in healthy controls ( P = 0.9). These data provide in vivo evidence that mitochondria-derived reactive oxygen species contribute to microvascular dysfunction in CKD and suggest that mitochondrial dysfunction may be a potential therapeutic target to improve CKD-related vascular dysfunction.
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Affiliation(s)
- Danielle L Kirkman
- Department of Kinesiology and Applied Physiology, University of Delaware , Newark, Delaware
| | - Bryce J Muth
- Department of Kinesiology and Applied Physiology, University of Delaware , Newark, Delaware
| | - Meghan G Ramick
- Department of Kinesiology and Applied Physiology, University of Delaware , Newark, Delaware
| | - Raymond R Townsend
- Clinical and Translational Research Center, University of Pennsylvania , Philadelphia, Pennsylvania
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware , Newark, Delaware
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Yeh YC, Chao A, Lee CY, Lee CT, Yeh CC, Liu CM, Tsai MK. An observational study of microcirculation in dialysis patients and kidney transplant recipients. Eur J Clin Invest 2017; 47:630-637. [PMID: 28683162 DOI: 10.1111/eci.12784] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Accepted: 07/04/2017] [Indexed: 12/15/2022]
Abstract
BACKGROUND Microcirculatory dysfunction contributes to acute and chronic kidney diseases. To the best of our knowledge, no study has compared differences in microcirculation among healthy volunteers, dialysis patients and kidney transplant recipients. MATERIALS AND METHODS Sublingual microcirculation was examined using sidestream dark field imaging and was compared among 90 healthy volunteers, 40 dialysis patients and 40 kidney transplant recipients. The gender effect on microcirculation and the correlations among the microcirculation parameters, age, body mass index, heart rate and blood pressure were analysed. RESULTS Total small vessel density, perfused small vessel density and the proportion of perfused small vessels were lower in the dialysis patients than in the healthy volunteers and kidney transplant recipients [total small vessel density; healthy volunteers vs. dialysis patients vs. kidney transplant recipients, 25·2 (2·3) vs. 22·8 (2·6) vs. 24·2 (2·9) mm/mm2 , P < 0·001]. Systolic blood pressure showed a weak negative correlation with the microvascular flow index scores in the healthy volunteers. By contrast, systolic blood pressure, diastolic blood pressure and mean arterial pressure showed weak positive correlations with proportion of perfused small vessels and the microvascular flow index scores in the dialysis patients. CONCLUSIONS Microcirculatory dysfunction is noted in dialysis patients, and this alteration is ameliorated in KT recipients. The positive correlation between blood pressure and microcirculation in dialysis patients suggests that additional studies should investigate the optimal goal of blood pressure management for dialysis patients.
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Affiliation(s)
- Yu Chang Yeh
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan
| | - Anne Chao
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chih-Yuan Lee
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Chen-Tse Lee
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Chuan Yeh
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
| | - Chih-Min Liu
- Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan
| | - Meng-Kun Tsai
- Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan
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Response of Blood Perfusion at ST 36 Acupoint after Drinking Cold Glucose or Saline Injection. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:4212534. [PMID: 28465703 PMCID: PMC5390596 DOI: 10.1155/2017/4212534] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 03/05/2017] [Indexed: 12/16/2022]
Abstract
Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in digestive system. According to acupuncture theory, change of SkBF at ST 36 might reflect the functional changes of digestive system. The aim of this study is to analyze the changes of SkBF after drinking 3°C 0.9% saline or 5% glucose injection by monitor blood flux at bilateral ST 36. The results indicated that, after drinking different cold water, the change ratio of SkBF at right side ST 36 has been different. Because all solutions have the same temperature (3°C) and both saline and glucose solution have the same osmolality, suggesting that the SkBF changes resulting from drinking cold water are not regulated just by the vagal tone and osmolality, there must have been other factors. These results have not been consistent with the frequency domain results of heart rate variability (HRV) analysis. Coherence analysis of blood flux signals at bilateral ST 36 indicated that there have been different coherence-frequency curves among different groups in special frequency bands, which suggested that coherence analysis might provide a potential tool to evaluate different status.
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Laterality and coherence analysis of Laser Doppler Flowmetry signals in bilateral Nèi guān (内关 PC 6): a potential non-invasive method to assess microdrculatory changes of people in different ages. WORLD JOURNAL OF ACUPUNCTURE-MOXIBUSTION 2017. [DOI: 10.1016/s1003-5257(17)30099-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
The heart and the vascular tree undergo major structural and functional changes when kidney function declines and renal replacement therapy is required. The many cardiovascular risk factors and adaptive changes the heart undergoes include left ventricular hypertrophy and dilatation with concomitant systolic and diastolic dysfunction. Myocardial fibrosis is the consequence of impaired angio-adaptation, reduced capillary angiogenesis, myocyte-capillary mismatch, and myocardial micro-arteriopathy. The vascular tree can be affected by both atherosclerosis and arteriosclerosis with both lipid rich plaques and abundant media calcification. Development of cardiac and vascular disease is rapid, especially in young patients, and the phenotype resembles all aspects of an accelerated ageing process and latent cardiac failure. The major cause of left ventricular hypertrophy and failure and the most common problem directly affecting myocardial function is fluid overload and, usually, hypertension. In situations of stress, such as intradialytic hypotension and hypoxaemia, the hearts of these patients are more vulnerable to developing cardiac arrest, especially when such episodes occur frequently. As a result, cardiac and vascular mortality are several times higher in dialysis patients than in the general population. Trials investigating one pharmacological intervention (eg, statins) have shown limitations. Pragmatic designs for large trials on cardio-active interventions are mandatory for adequate cardioprotective renal replacement therapy.
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Affiliation(s)
- Christoph Wanner
- Comprehensive Heart Failure Center and Renal Division, University Hospital of Würzburg, Würzburg, Germany.
| | - Kerstin Amann
- Department of Nephropathology at the Department of Pathology, University of Erlangen-Nürnberg, Erlangen, Germany
| | - Tetsuo Shoji
- Department of Geriatrics and Vascular Medicine, Osaka City University Graduate School of Medicine, Osaka, Japan
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Seliger SL, Salimi S, Pierre V, Giffuni J, Katzel L, Parsa A. Microvascular endothelial dysfunction is associated with albuminuria and CKD in older adults. BMC Nephrol 2016; 17:82. [PMID: 27412615 PMCID: PMC4944235 DOI: 10.1186/s12882-016-0303-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Accepted: 07/07/2016] [Indexed: 02/07/2023] Open
Abstract
Background Impairment in glomerular endothelial function likely plays a major role in the development of albuminuria and CKD progression. Glomerular endothelial dysfunction may reflect systemic microvascular dysfunction, accounting in part for the greater cardiovascular risk in patients with albuminuria. Prior studies of vascular function in CKD have focused on conduit artery function or those with ESRD, and have not examined microvascular endothelial function with albuminuria. Methods We conducted a cross-sectional study among older hypertensive male veterans with stage 1–4 CKD, and hypertensive controls without CKD. Microvascular function was quantified by two distinct Laser-Doppler flowmetry (LDF) measures: peak responses to 1) post-occlusive reactive hyperemia (PORH) and 2) thermal hyperemia (TH), measured on forearm skin. Associations of each LDF measure with albuminuria, eGFR, and CKD status were estimated using correlation coefficients and multiple linear regression, accounting for potential confounders. Results Among 66 participants (mean age 69.2 years), 36 had CKD (mean eGFR 46.1 cc/min/1.73 m2; 30.6 % with overt albuminuria). LDF responses to PORH and TH were 43 and 39 % significantly lower in multivariate analyses among those with macroalbuminuria compared to normoalbuminuria, (β= − 0.42, p = 0.009 and β= −0.37, p = 0.01, respectively). Those with CKD had a 23.9 % lower response to PORH compared to controls (p = 0.02 after adjustment). In contrast, TH responses did not differ between those with and without CKD. Conclusions Microvascular endothelial function was strongly associated with greater albuminuria and CKD, independent of diabetes and blood pressure. These findings may explain in part the excess systemic cardiovascular risk associated with albuminuria and CKD.
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Affiliation(s)
- Stephen L Seliger
- Department of Medicine, University of Maryland School of Medicine, 22 S. Greene Street, Room N3W143, Baltimore, MD, 21201, USA. .,Medicine, VA Maryland Healthcare System, Baltimore, USA.
| | - Shabnam Salimi
- Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore, USA
| | | | - Jamie Giffuni
- GRECC, VA Maryland Healthcare System, Baltimore, USA
| | - Leslie Katzel
- Department of Medicine, University of Maryland School of Medicine, 22 S. Greene Street, Room N3W143, Baltimore, MD, 21201, USA.,GRECC, VA Maryland Healthcare System, Baltimore, USA
| | - Afshin Parsa
- Department of Medicine, University of Maryland School of Medicine, 22 S. Greene Street, Room N3W143, Baltimore, MD, 21201, USA.,Medicine, VA Maryland Healthcare System, Baltimore, USA
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Munisamy S, Daud KM, Mokhtar SS, Rasool AH. Effects of 1α-Calcidol (Alfacalcidol) on Microvascular Endothelial Function, Arterial Stiffness, and Blood Pressure in Type II Diabetic Nephropathy Patients. Microcirculation 2016; 23:53-61. [DOI: 10.1111/micc.12256] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2015] [Accepted: 11/05/2015] [Indexed: 12/21/2022]
Affiliation(s)
- Seetha Munisamy
- Pharmacology Vascular Laboratory; Universiti Sains Malaysia; Kota Bharu Malaysia
| | - Kamaliah M. Daud
- Medical Department; School of Medical Sciences; Universiti Sains Malaysia; Kota Bharu Malaysia
| | - Siti S. Mokhtar
- Pharmacology Vascular Laboratory; Universiti Sains Malaysia; Kota Bharu Malaysia
| | - Aida H.G Rasool
- Pharmacology Vascular Laboratory; Universiti Sains Malaysia; Kota Bharu Malaysia
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Cavka A, Cosic A, Jukic I, Jelakovic B, Lombard JH, Phillips SA, Seric V, Mihaljevic I, Drenjancevic I. The role of cyclo-oxygenase-1 in high-salt diet-induced microvascular dysfunction in humans. J Physiol 2015; 593:5313-24. [PMID: 26498129 DOI: 10.1113/jp271631] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 10/19/2015] [Indexed: 01/11/2023] Open
Abstract
KEY POINTS Recent studies have shown that some of the deleterious effects of a high-salt (HS) diet are independent of elevated blood pressure and are associated with impaired endothelial function. Increased generation of cyclo-oxygenase (COX-1 and COX-2)-derived vasoconstrictor factors and endothelial activation may contribute to impaired vascular relaxation during HS loading. The present study aimed to assess the regulation of microvascular reactivity and to clarify the role of COX-1 and COX-2 in normotensive subjects on a short-term HS diet. The present study demonstrates the important role of COX-1 derived vasoconstrictor metabolites in regulation of microvascular blood flow during a HS diet. These results help to explain how even short-term HS diets may impact upon microvascular reactivity without changes in blood pressure and suggest that a vasoconstrictor metabolite of COX-1 could play a role in this impaired tissue blood flow. ABSTRACT The present study aimed to assess the effect of a 1-week high-salt (HS) diet on the role of cyclo-oxygenases (COX-1 and COX-2) and the vasoconstrictor prostaglandins, thromboxane A2 (TXA2 ) and prostaglandin F2α (PGF2α ), on skin microcirculatory blood flow, as well as to detect its effect on markers of endothelial activation such as soluble cell adhesion molecules. Young women (n = 54) were assigned to either the HS diet group (N = 30) (∼14 g day(-1) NaCl ) or low-salt (LS) diet group (N = 24) (<2.3 g day(-1) NaCl ) for 7 days. Post-occlusive reactive hyperaemia (PORH) in the skin microcirculation was assessed by laser Doppler flowmetry. Plasma renin activity, plasma aldosterone, plasma and 24 h urine sodium and potassium, plasma concentrations of TXB2 (stable TXA2 metabolite) and PGF2α , soluble cell adhesion molecules and blood pressure were measured before and after the diet protocols. One HS diet group subset received 100 mg of indomethacin (non-selective COX-1 and COX-2 inhibitor), and another HS group subset received 200 mg of celecoxib (selective COX-2 inhibitor) before repeating laser Doppler flowmetry measurements. Blood pressure was unchanged after the HS diet, although it significantly reduced after the LS diet. Twenty-four hour urinary sodium was increased, and plasma renin activity and plasma aldosterone levels were decreased after the HS diet. The HS diet significantly impaired PORH and increased TXA2 but did not change PGF2α levels. Indomethacin restored microcirculatory blood flow and reduced TXA2 . By contrast, celecoxib decreased TXA2 levels but had no significant effects on blood flow. Restoration of of PORH by indomethacin during a HS diet suggests an important role of COX-1 derived vasoconstrictor metabolites in the regulation of microvascular blood flow during HS intake.
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Affiliation(s)
- Ana Cavka
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Anita Cosic
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Ivana Jukic
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
| | - Bojan Jelakovic
- School of Medicine University of Zagreb, Department of Nephrology, Hypertension, Dialysis and Transplantation, University Hospital Centre Zagreb, Zagreb, Croatia
| | - Julian H Lombard
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Shane A Phillips
- Department of Physical Therapy, College of Applied Health Sciences, University of Illinois in Chicago, Chicago, IL, USA
| | - Vatroslav Seric
- Department of Clinical Laboratory Diagnostics, University Hospital Osijek, Osijek, Croatia
| | - Ivan Mihaljevic
- Clinical Institute of Nuclear Medicine and Radiation Protection, University Hospital Osijek, Osijek, Croatia
| | - Ines Drenjancevic
- Department of Physiology and Immunology, Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Osijek, Croatia
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Murbach M, Neufeld E, Cabot E, Zastrow E, Córcoles J, Kainz W, Kuster N. Virtual population-based assessment of the impact of 3 Tesla radiofrequency shimming and thermoregulation on safety and B1 + uniformity. Magn Reson Med 2015; 76:986-97. [PMID: 26400841 DOI: 10.1002/mrm.25986] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 07/20/2015] [Accepted: 08/21/2015] [Indexed: 01/22/2023]
Abstract
PURPOSE To assess the effect of radiofrequency (RF) shimming of a 3 Tesla (T) two-port body coil on B1 + uniformity, the local specific absorption rate (SAR), and the local temperature increase as a function of the thermoregulatory response. METHODS RF shimming alters induced current distribution, which may result in large changes in the level and location of absorbed RF energy. We investigated this effect with six anatomical human models from the Virtual Population in 10 imaging landmarks and four RF coils. Three thermoregulation models were applied to estimate potential local temperature increases, including a newly proposed model for impaired thermoregulation. RESULTS Two-port RF shimming, compared to circular polarization mode, can increase the B1 + uniformity on average by +32%. Worst-case SAR excitations increase the local RF power deposition on average by +39%. In the first level controlled operating mode, induced peak temperatures reach 42.5°C and 45.6°C in patients with normal and impaired thermoregulation, respectively. CONCLUSION Image quality with 3T body coils can be significantly increased by RF shimming. Exposure in realistic scan scenarios within guideline limits can be considered safe for a broad patient population with normal thermoregulation. Patients with impaired thermoregulation should not be scanned outside of the normal operating mode. Magn Reson Med 76:986-997, 2016. © 2015 Wiley Periodicals, Inc.
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Affiliation(s)
| | | | | | - Earl Zastrow
- IT'IS Foundation, Zurich, Switzerland.,Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
| | - Juan Córcoles
- Department of Electronic and Communication Technology, Universidad Autónoma de Madrid (UAM), Escuela Politécnica Superior, Madrid, Spain
| | - Wolfgang Kainz
- US Food and Drug Administration (FDA), Center for Devices and Radiological Health (CDRH), Silver Spring, Maryland, USA
| | - Niels Kuster
- IT'IS Foundation, Zurich, Switzerland.,Swiss Federal Institute of Technology (ETH), Zurich, Switzerland
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Goligorsky MS. Pathogenesis of endothelial cell dysfunction in chronic kidney disease: a retrospective and what the future may hold. Kidney Res Clin Pract 2015; 34:76-82. [PMID: 26484026 PMCID: PMC4570605 DOI: 10.1016/j.krcp.2015.05.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 05/04/2015] [Accepted: 05/15/2015] [Indexed: 12/31/2022] Open
Abstract
Cardiovascular complications dominate the landscape of chronic kidney diseases (CKD). Endothelial cell dysfunction (ECD) is a well-known culprit of cardiovascular morbidity and it develops in CKD with remarkable frequency. This brief overview of ECD in CKD scans two decades of studies performed in my laboratory, from genetic analyses to proteomic and metabolomics screens. I provide a detailed description of findings related to the premature senescence of endothelial cells, cell transition from the endothelial to mesenchymal phenotype, and stages of development of ECD. Clinical utility of some of these findings is illustrated with data on laser-Doppler flowmetry and imaging in patients with CKD. Some currently available and emerging therapeutic options for the management of ECD are briefly presented.
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Affiliation(s)
- Michael S Goligorsky
- Departments of Medicine, Pharmacology and Physiology, Renal Research Institute, New York Medical College, Valhalla, NY, USA ; Departments of Pharmacology and Physiology, Pharmacology and Physiology, Renal Research Institute, New York Medical College, Valhalla, NY, USA
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41
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Wavelet-analysis of skin temperature oscillations during local heating for revealing endothelial dysfunction. Microvasc Res 2015; 97:109-14. [DOI: 10.1016/j.mvr.2014.10.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Revised: 10/16/2014] [Accepted: 10/17/2014] [Indexed: 11/23/2022]
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Wierzbowska J, Wojtkiewicz S, Zbieć A, Wierzbowski R, Liebert A, Maniewski R. Prolonged postocclusive hyperemia response in patients with normal-tension glaucoma. Med Sci Monit 2014; 20:2607-16. [PMID: 25502623 PMCID: PMC4266367 DOI: 10.12659/msm.891069] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Background It is believed that endothelial dysfunction may be a link between systemic and ocular dysregulation in glaucoma. The aim of this study was to evaluate peripheral vascular reactive hyperemia in response to occlusion test and to correlate peripheral vascular findings with retrobulbar hemodynamics parameters in patients with normal-tension glaucoma. Material/Methods Forty-eight patients with normal-tension glaucoma (mean age 58.1 years, 38 women) and 40 control subjects (mean age 54.1 years, 36 women) were subjected to a brachial arterial occlusion test and color Doppler imaging (LOGIQ 9, GE Medical Systems) of the retrobulbar arteries. Finger hyperemia was assessed by using a 2-channel laser Doppler flowmeter (MBF-3D, Moor Instruments, Ltd.). Time parameters (time to peak flow, half-time of hyperemia, time of recovery) and amplitude parameters (maximum hyperemia response, biological zero) of the post-occlusive reactive hyperemia signal pattern as well as velocities and resistance index of the ophthalmic, central retinal, and short posterior ciliary arteries were evaluated and compared between study groups. Results In glaucoma patients, time to peak flow and half-time of hyperemia were significantly longer (21.4 vs. 12.0 s, p=0.02 and 74.1 vs. 44.2 s, p=0.03, respectively) and biological zero was significantly lower (2.4 vs. 3.2, p=0.01) comparing with healthy subjects. In glaucoma patients, peak-systolic and end-diastolic velocities of central retinal artery were significantly lower (12.8 vs.14.1, p=0.03 and 3.9 vs. 4.7, p=0.01, respectively) and resistance index of this artery was significantly higher (0.69 vs. 0.67, p=0.03) compared to controls. In the glaucoma group, maximum hyperemic response was negatively correlated with the resistance index of temporal short posterior ciliary arteries (r=−0.4, p=0.01), whereas in the control group half-time of hyperemia was negatively correlated with end-diastolic velocity of the central retinal artery (r=−0.3, p=0.03). Conclusions Arterial occlusion test elicited a prolonged systemic hyperemia response in patients with glaucoma as compared with healthy subjects. Retrobulbar blood flow alterations in glaucoma patients may be related to systemic vascular dysregulation.
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Affiliation(s)
- Joanna Wierzbowska
- Department of Ophthalmology, Military Institute of Medicine, Warsaw, Poland
| | - Stanisław Wojtkiewicz
- Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Anna Zbieć
- Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Robert Wierzbowski
- Department of Cardiology, Military Institute of Medicine, Warsaw, Poland
| | - Adam Liebert
- Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Roman Maniewski
- Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
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Johnson JM, Minson CT, Kellogg DL. Cutaneous vasodilator and vasoconstrictor mechanisms in temperature regulation. Compr Physiol 2014; 4:33-89. [PMID: 24692134 DOI: 10.1002/cphy.c130015] [Citation(s) in RCA: 241] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
In this review, we focus on significant developments in our understanding of the mechanisms that control the cutaneous vasculature in humans, with emphasis on the literature of the last half-century. To provide a background for subsequent sections, we review methods of measurement and techniques of importance in elucidating control mechanisms for studying skin blood flow. In addition, the anatomy of the skin relevant to its thermoregulatory function is outlined. The mechanisms by which sympathetic nerves mediate cutaneous active vasodilation during whole body heating and cutaneous vasoconstriction during whole body cooling are reviewed, including discussions of mechanisms involving cotransmission, NO, and other effectors. Current concepts for the mechanisms that effect local cutaneous vascular responses to local skin warming and cooling are examined, including the roles of temperature sensitive afferent neurons as well as NO and other mediators. Factors that can modulate control mechanisms of the cutaneous vasculature, such as gender, aging, and clinical conditions, are discussed, as are nonthermoregulatory reflex modifiers of thermoregulatory cutaneous vascular responses.
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Affiliation(s)
- John M Johnson
- Department of Physiology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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El-Nahid MS, El-Ashmaoui AM. Functional and structural abnormalities of the skin microcirculation in hemodialysis patients. THE EGYPTIAN JOURNAL OF INTERNAL MEDICINE 2014. [DOI: 10.4103/1110-7782.145307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Salgado MAM, Salgado-Filho MF, Reis-Brito JO, Lessa MA, Tibirica E. Effectiveness of laser Doppler perfusion monitoring in the assessment of microvascular function in patients undergoing on-pump coronary artery bypass grafting. J Cardiothorac Vasc Anesth 2014; 28:1211-6. [PMID: 25125374 DOI: 10.1053/j.jvca.2014.03.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Indexed: 11/11/2022]
Abstract
OBJECTIVES To evaluate the effectiveness of single-point laser Doppler perfusion monitoring (LDPM) in the assessment of microvascular reactivity in the skin during cardiopulmonary bypass (CPB). DESIGN Cross-sectional observational study. SETTING Government-affiliated teaching hospital. PARTICIPANTS Twenty male patients aged 60 ± 2 years who underwent coronary artery bypass grafting under CPB. INTERVENTIONS The authors assessed the endothelium-dependent vasodilation of the skin microcirculation at the forehead and forearm using LDPM coupled with thermal hyperemia. This measurement was performed before and after the induction of anesthesia, during and after CPB, and 24 h after the end of the surgical procedure. RESULTS The basal values of microvascular flow before the induction of anesthesia were significantly higher in the skin of the forehead compared with that of the forearm. There were no significant alterations in microvascular reactivity throughout the recording periods for both recording sites, as assessed by the vasodilation range expressed as cutaneous vascular conductance (arbitrary perfusion units/mean arterial pressure). CONCLUSIONS Using LDPM, the authors showed that the microcirculatory bed of the skin of the forehead, which is readily accessible during cardiac surgery, is a suitable model for the study of microvascular reactivity and tissue perfusion in cardiovascular surgical procedures using CPB. This technique could, thus, be suitable for evaluating the effects of drugs or technical procedures on tissue perfusion during cardiac surgery under cardiopulmonary bypass.
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Affiliation(s)
| | | | | | - Marcos A Lessa
- Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil
| | - Eduardo Tibirica
- National Institute of Cardiology, Ministry of Health; Laboratory of Cardiovascular Investigation, Oswaldo Cruz Institute, FIOCRUZ, Rio de Janeiro, Brazil.
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DuPont JJ, Ramick MG, Farquhar WB, Townsend RR, Edwards DG. NADPH oxidase-derived reactive oxygen species contribute to impaired cutaneous microvascular function in chronic kidney disease. Am J Physiol Renal Physiol 2014; 306:F1499-506. [PMID: 24761000 PMCID: PMC4059972 DOI: 10.1152/ajprenal.00058.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/21/2014] [Indexed: 01/11/2023] Open
Abstract
Oxidative stress promotes vascular dysfunction in chronic kidney disease (CKD). We utilized the cutaneous circulation to test the hypothesis that reactive oxygen species derived from NADPH oxidase and xanthine oxidase impair nitric oxide (NO)-dependent cutaneous vasodilation in CKD. Twenty subjects, 10 stage 3 and 4 patients with CKD (61 ± 4 yr; 5 men/5 women; eGFR: 39 ± 4 ml·min(-1)·1.73 m(-2)) and 10 healthy controls (55 ± 2 yr; 4 men/6 women; eGFR: >60 ml·min(-1)·1.73 m(-2)) were instrumented with 4 intradermal microdialysis fibers for the delivery of 1) Ringer solution (Control), 2) 10 μM tempol (scavenge superoxide), 3) 100 μM apocynin (NAD(P)H oxidase inhibition), and 4) 10 μM allopurinol (xanthine oxidase inhibition). Skin blood flow was measured via laser-Doppler flowmetry during standardized local heating (42°C). N(g)-nitro-l-arginine methyl ester (L-NAME; 10 mM) was infused to quantify the NO-dependent portion of the response. Cutaneous vascular conductance (CVC) was calculated as a percentage of the maximum CVC achieved during sodium nitroprusside infusion at 43°C. Cutaneous vasodilation was attenuated in patients with CKD (77 ± 3 vs. 88 ± 3%, P = 0.01), but augmented with tempol and apocynin (tempol: 88 ± 2 (P = 0.03), apocynin: 91 ± 2% (P = 0.001). The NO-dependent portion of the response was reduced in patients with CKD (41 ± 4 vs. 58 ± 2%, P = 0.04), but improved with tempol and apocynin (tempol: 58 ± 3 (P = 0.03), apocynin: 58 ± 4% (P = 0.03). Inhibition of xanthine oxidase did not alter cutaneous vasodilation in either group (P > 0.05). These data suggest that NAD(P)H oxidase is a source of reactive oxygen species and contributes to microvascular dysfunction in patients with CKD.
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Affiliation(s)
- Jennifer J DuPont
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Meghan G Ramick
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; Department of Biological Sciences, University of Delaware, Newark, Delaware; and
| | - Raymond R Townsend
- Clinical and Translational Research Center, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; Department of Biological Sciences, University of Delaware, Newark, Delaware; and
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Fedorovich AA, Rogoza AN, Chikhladze NM. Characteristics of functional state of arteriolar and venular skin microvessels in patients with essential arterial hypertension. Microvasc Res 2014; 93:105-13. [DOI: 10.1016/j.mvr.2014.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Revised: 04/11/2014] [Accepted: 04/12/2014] [Indexed: 11/30/2022]
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Fujii N, Brunt VE, Minson CT. Tempol improves cutaneous thermal hyperemia through increasing nitric oxide bioavailability in young smokers. Am J Physiol Heart Circ Physiol 2014; 306:H1507-11. [PMID: 24682395 DOI: 10.1152/ajpheart.00886.2013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We recently found that young cigarette smokers display cutaneous vascular dysfunction relative to nonsmokers, which is partially due to reduced nitric oxide (NO) synthase (NOS)-dependent vasodilation. In this study, we tested the hypothesis that reducing oxidative stress improves NO bioavailability, enhancing cutaneous vascular function in young smokers. Ten healthy young male smokers, who had smoked for 6.3 ± 0.7 yr with an average daily consumption of 9.1 ± 0.7 cigarettes, were tested. Cutaneous vascular conductance (CVC) during local heating to 42°C at a rate of 0.1°C/s was evaluated as laser-Doppler flux divided by mean arterial blood pressure and normalized to maximal CVC, induced by local heating to 44°C plus sodium nitroprusside administration. We evaluated plateau CVC during local heating, which is known to be highly dependent on NO, at four intradermal microdialysis sites with 1) Ringer solution (control); 2) 10 μM 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol), a superoxide dismutase mimetic; 3) 10 mM N(ω)-nitro-l-arginine (l-NNA), a nonspecific NOS inhibitor; and 4) a combination of 10 μM tempol and 10 mM l-NNA. Tempol increased plateau CVC compared with the Ringer solution site (90.0 ± 2.3 vs. 77.6 ± 3.9%maximum, P = 0.028). Plateau CVC at the combination site (56.8 ± 4.5%maximum) was lower than the Ringer solution site (P < 0.001) and was not different from the l-NNA site (55.1 ± 4.6%maximum, P = 0.978), indicating the tempol effect was exclusively NO dependent. These data suggest that in young smokers, reducing oxidative stress improves cutaneous thermal hyperemia to local heating by enhancing NO production.
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Affiliation(s)
- Naoto Fujii
- Department of Human Physiology, The University of Oregon, Eugene, Oregon
| | - Vienna E Brunt
- Department of Human Physiology, The University of Oregon, Eugene, Oregon
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Wang G, Tian Y, Jia S, Zhou W, Zhang W. Pilot study of blood perfusion coherence along the meridian in forearm. Altern Ther Health Med 2013; 13:327. [PMID: 24267384 PMCID: PMC3842661 DOI: 10.1186/1472-6882-13-327] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 11/19/2013] [Indexed: 11/28/2022]
Abstract
Background Many studies have explored the relationship between skin microcirculation and meridian activation. However, few studies have examined blood perfusion coherence along the meridians, and other studies have suggested that the skin vasodilator response relates to age. This study investigated blood perfusion coherence characteristics along the meridian of the forearm in healthy volunteers. Methods A total of 15 young subjects (25.53 ± 2.20) and 15 middle-aged subjects (50.07 ± 3.37) were recruited for this study. Before experiments, each subject was placed in a temperature-controlled room for 60 min. Skin blood perfusion from five points was recorded simultaneously using a full-field laser perfusion imager before and after inflatable occlusion. The five points comprised three points located on the pericardium meridian, and two points from different locations. Coherence analysis between these points was performed at different frequency intervals from 0.0095 to 2 Hz. Results In young subjects, the coherence value was unchanged before and after occlusion, and there was no significant difference in coherence value between meridian-meridian points (M-M) and meridian-parameridian points (M-P). In middle-aged subjects, the coherence value increased significantly in both M-M and M-P at frequency intervals of 0.14-0.4 Hz, 0.4-1.6 Hz, and 1.6-2 Hz. However, there was no significant difference in coherence values between M-M and M-P. Conclusions Inflatable occlusion can increase middle-aged subjects’ blood perfusion coherence value of the forearm. However, there is no specificity in meridian location.
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HIF isoforms in the skin differentially regulate systemic arterial pressure. Proc Natl Acad Sci U S A 2013; 110:17570-5. [PMID: 24101470 DOI: 10.1073/pnas.1306942110] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Vascular flow through tissues is regulated via a number of homeostatic mechanisms. Localized control of tissue blood flow, or autoregulation, is a key factor in regulating tissue perfusion and oxygenation. We show here that the net balance between two hypoxia-inducible factor (HIF) transcription factor isoforms, HIF-1α and HIF-2α, is an essential mechanism regulating both local and systemic blood flow in the skin of mice. We also show that balance of HIF isoforms in keratinocyte-specific mutant mice affects thermal adaptation, exercise capacity, and systemic arterial pressure. The two primary HIF isoforms achieve these effects in opposing ways that are associated with HIF isoform regulation of nitric oxide production. We also show that a correlation exists between altered levels of HIF isoforms in the skin and the degree of idiopathic hypertension in human subjects. Thus, the balance between HIF-1α and HIF-2α expression in keratinocytes is a control element of both tissue perfusion and systemic arterial pressure, with potential implications in human hypertension.
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