Microcirculation最新文献

{"title":"Microvascular Consequences of Methemoglobin Compared to Reduced Hemoglobin in the Microcirculation","authors":"Jacinda Martinez,&nbsp;Carlos Munoz,&nbsp;Daniela Lucas,&nbsp;Cynthia Muller,&nbsp;Krianthan Govender,&nbsp;Xiangming Gu,&nbsp;Andre F. Palmer,&nbsp;Pedro Cabrales","doi":"10.1111/micc.70022","DOIUrl":"https://doi.org/10.1111/micc.70022","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>The development of hemoglobin-based oxygen carriers (HBOCs) offers a promising alternative to traditional blood transfusions, addressing critical limitations such as the need for cold storage, blood type matching, and a short ex vivo shelf life. HBOCs mimic the oxygen-carrying function of red blood cells without the risk of transfusion-related complications. However, hemoglobin is prone to oxidation when freely circulating in the vasculature, resulting in methemoglobin formation. In this oxidized state, Hb does not transport oxygen, scavenges less nitric oxide, but it is more toxic. As continued research tries to develop effective HBOCs for use in emergency medicine, there needs to be an understanding of the microvascular and toxicological effects of the reduced and oxidized forms of Hb.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>The study involved Golden Syrian Hamsters instrumented with a dorsal skin window chamber model to observe the acute effects resulting from a hypervolemic infusion (10% of the animal's blood volume) of human Hb [HbFe²⁺ (hHb)] or methemoglobin [HbFe³⁺ (met-hHb)] and lactated Ringer's solution as a volume control. Microhemodynamics, mean arterial pressure, heart rate, blood gases, and blood properties were measured.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Mean arterial pressure (MAP) and heart rate (HR) were both altered; animals infused with hHb saw a significant increase in MAP and a decrease in HR, while animals infused with met-hHb saw a significant decrease in MAP and a decrease in HR. Infusion of hHb induced vasoconstriction and hypertension. However, infusion of met-hHb resulted in increased microvascular diameters compared to baseline, but a reduction in functional capillary density compared to baseline, alongside significant increases in inflammation, specifically in systemic and cardiac markers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>This study illuminates the complex impact of Hb oxidation on microvascular function and inflammation, pivotal to understanding the safety and efficacy of HBOC formulations. Future research should focus on strategies to regulate Hb oxidation to enhance therapeutic benefit and minimize detrimental effects in emergency medicine settings.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144905576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Coronary Microvascular Dysfunction Alters the Pulsatile Behavior of the Resting Coronary Blood Flow","authors":"Ahmet Tas,&nbsp;Yaren Alan,&nbsp;Ilke Kara Tas,&nbsp;Omer E. Aydin,&nbsp;Zeynep Atay,&nbsp;Sule Yilmaz,&nbsp;Alp Ozcan,&nbsp;Tim P. van de Hoef,&nbsp;Sabahattin Umman,&nbsp;Jan J. Piek MD,&nbsp;Murat Sezer","doi":"10.1111/micc.70021","DOIUrl":"https://doi.org/10.1111/micc.70021","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Variations in resting pulsatile coronary flow velocity acceleration/deceleration characteristics (dU/dt) with respect to epicardial lesions and coronary microvascular dysfunction (CMD) remain incompletely understood.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Method</h3>\u0000 \u0000 <p>The coronary dU/dt pattern was extracted from the first derivative of the intracoronary Doppler velocity signal. Univariable and multivariable models evaluated the relationships between the dU/dt amplitudes, epicardial disease as well as CMD, defined by a blunted coronary flow reserve (CFR) adjusted for the concomitant epicardial disease severity (fractional flow reserve, FFR) yielding the microvascular resistance reserve (MRR). Functional CMD was defined by a blunted MRR (≤ 3.0) but normal hyperemic microvascular resistance (hMR &lt; 2.5) whereas structural CMD was defined by a blunted MRR (≤ 3.0) combined with increased hMR (≥ 2.5). Six major acceleration or deceleration peaks were identified in each cardiac cycle; these were a (amplitude of peak diastolic acceleration), b (amplitude of early diastolic deceleration nadir), c (amplitude of peak diastolic re-acceleration), j (amplitude of end-diastolic deceleration nadir), x (amplitude of peak systolic acceleration), and z (amplitude of end-systolic deceleration nadir) waves.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Functional CMD was associated with amplification of a (<i>β</i> = 55.944, 95% CI [21.112, 90.777], <i>p</i> = 0.002) and × (<i>β</i> = 44.069, 95% CI [20.182, 67.955], <i>p</i> &lt; 0.001), b (<i>β</i> = −34.019, 95% CI [−50.865, −17.173], <i>p</i> &lt; 0.001), j (<i>β</i> = −48.723, 95% CI [−71.272, −26.174], <i>p</i> &lt; 0.001), and z (<i>β</i> = −31.047, 95% CI [−53.596, −8.498], <i>p</i> = 0.007) waves. Structural CMD was associated with blunted a (<i>β</i> = −76.938, 95% CI [−113.125, −40.751], <i>p</i> &lt; 0.001) and j (<i>β</i> = 24.787, 95% CI [1.361, 48.213], <i>p</i> = 0.039).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Epicardial disease severity is minimally associated with alterations in the resting dU/dt pattern, whereas CMD endotypes are associated with distinctively altered intrabeat pulsatility characteristics. Stronger acceleration magnitudes at rest do not indicate a healthier microcirculation or absence of CMD.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Trial Registration</h3>\u0000 \u0000 <p>ClinicalTrials.gov (NCT02328820)</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.70021","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144869690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The British Microcirculation & Vascular Biology Society","authors":"","doi":"10.1111/micc.70020","DOIUrl":"https://doi.org/10.1111/micc.70020","url":null,"abstract":"","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 6","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144833275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Homocysteine Induces Brain and Retinal Microvascular Endothelial Cell Barrier Damage and Hyperpermeability via NLRP3 Inflammasome Pathway Differentially","authors":"O'lisa Yaa Waithe,&nbsp;Aliyah Anderson,&nbsp;Saravanakumar Muthusamy,&nbsp;Gabriela M. Seplovich,&nbsp;Binu Tharakan","doi":"10.1111/micc.70019","DOIUrl":"https://doi.org/10.1111/micc.70019","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>The amino acid homocysteine (HCY) has been implicated in the pathobiology of several conditions, including spaceflight-associated neuro-ocular syndrome (SANS)—a collection of symptoms affecting near vision in astronauts. Blood-retinal barrier (BRB) and blood–brain barrier (BBB) dysfunctions are implicated in the pathobiology of SANS. Our objective was to assess how HCY affects BRB/BBB permeability and the role of the NLRP3 inflammasome in the modulation of such effects.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Human brain and retinal microvascular endothelial cells (HBMECs and HRMECs) were treated with 100 μM HCY alone or in conjunction with NLRP3 inflammasome inhibitor MCC950 at 1 μM. The assays performed included fluorometric assays to measure cell viability, an enzyme assay for caspase-1, expression of BRB/BBB tight junction protein zonula occludens-1 (ZO-1) by RT-PCR, and barrier permeability using FITC-dextran.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>In HRMECs and HBMECs, HCY-induced endothelial monolayer hyperpermeability significantly (<i>p</i> &lt; 0.05). In HBMECs, the effect was attenuated by MCC950 (<i>p</i> &lt; 0.05). Increased Caspase-1 activity was observed in both cell types following the addition of HCY. Following HCY addition, gene expression results denoting barrier damage were observed, particularly that of ZO-1 (<i>p</i> &lt; 0.05).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>HCY induces hyperpermeability in retinal and brain endothelial cells. NLRP3-mediation in HCY-induced microvascular permeability is prominent in brain endothelial cells compared to retinal endothelial cells.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mechanically Tunable Poly(Ethylene Glycol) Diacrylate Hydrogels Reveal Stiffness-Related Impairments in Capillary Sprouting in Experimental Lung Fibrosis","authors":"Julie Leonard-Duke,&nbsp;Samuel M. J. Agro,&nbsp;David J. Csordas,&nbsp;Riley T. Hannan,&nbsp;Anthony C. Bruce,&nbsp;Jeffrey M. Sturek,&nbsp;Shayn M. Peirce,&nbsp;Lakeshia J. Taite","doi":"10.1111/micc.70018","DOIUrl":"https://doi.org/10.1111/micc.70018","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>Synthetic hydrogels that support 3D cell culture are widely used as platforms for modeling disease, such as tissue fibrosis, which leads to mechanical stiffening of the extracellular matrix (ECM). To interrogate how mechanical stiffness of the ECM affects microvascular remodeling, we developed a bioactive poly(ethylene glycol) diacrylate (PEGDA) hydrogel model with tunable stiffness that permits microvascular sprouting.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Lung explants harvested from healthy and fibrotic mice were cultured ex vivo on PEGDA hydrogels for 7 days. Capillary sprouting from lung segments was evaluated via imaging and secreted angiogenic markers.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Healthy lung explants had decreased sprout formation and length on stiffer hydrogels. The sprouts from fibrotic lung explants, however, were not impacted by hydrogel stiffness. This difference was associated with higher expression of angiogenic markers and matrix remodeling enzymes in the fibrotic lung explants.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Our results suggest a compensation in vasculature derived from fibrotic tissue to matrix mechanics in promoting angiogenic sprouting.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.70018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144647120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"COVID-19 Patients Have Peripheral Microvascular Dysfunction and Tissue Hypoxia in Spite of Successful Treatment of Lung Failure: A Proof of Concept Study","authors":"Knut Kvernebo,&nbsp;L. Liv Kristin Wikslund,&nbsp;Kamila Drezek,&nbsp;Andrea Jaramillo,&nbsp;Luigino Capone,&nbsp;Maged Helmy,&nbsp;Yunong Zhao,&nbsp;Aaron Aguirre,&nbsp;David D'Alessandro","doi":"10.1111/micc.70014","DOIUrl":"https://doi.org/10.1111/micc.70014","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>Availability of oxygen (O₂) is essential for life and function of all cells of the human body (<i>n</i> ≈ 10¹³–10¹⁴ cells). COVID-19 patients often have impaired lung function with compromised oxygen uptake, but little is known about microvascular oxygen delivery and tissue oxygenation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Use the Oxygen Delivery Index (ODIN) concept to assess peripheral microvascular regulation and oxygen extraction in COVID-19 patients.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>The ODIN concept includes two technologies (diffuse reflectance spectroscopy—DRS and computer assisted microscopy—CAM) for data acquisition from subepidermal nutritive capillaries. Output parameters are microvascular oxygen saturation (SmvO₂) and functional capillary density (FCD).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Forty patients hospitalized for COVID-19 grouped into early discharge (&lt; 7 days, <i>n</i> = 11), severe (beyond 7 days, <i>n</i> = 24) and non-survivors (<i>n</i> = 5), and healthy controls (<i>n</i> = 23) were examined.</p>\u0000 \u0000 <p>Microvascular oxygen saturation (SmvO₂) and the corresponding O₂ extraction (SaO₂—SmvO₂) was 56% ± 4%/42% ± 9% (mean ± SD) in healthy controls (<i>n</i> = 11), 61 ± 10/37 ± 10 for historic controls (<i>n</i> = 12), significantly different (<i>p</i> &lt; 0.01) as compared with all COVID-19 groups (early discharge: 40% ± 13%/54% ± 13%, severe: 34% ± 15%/60% ± 15%, non-survivors 22% ± 15%/73% ± 16%). FCD expressed as the relative number of red pixels (belonging to a capillary erythrocyte) in a CAM frame were reduced in alle patient groups as compared to historic controls (<i>p</i> &lt; 0⋅05).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Results show skin microvascular dysregulation and tissue hypoxia in patients, indicative of hypoxia also in other tissues. We hypothesize that tissue hypoxia is a cause of reversible and non-reversible long COVID-19 symptoms and of mortality.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144525030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regulatory T Cells Control Vascular Adhesion Molecule Expression in Skin Under Inflammatory and Homeostatic Conditions","authors":"M. Ursula Norman,&nbsp;Brandon Lim,&nbsp;Lucinda Jenkins,&nbsp;Pam Hall,&nbsp;Sarah L. Snelgrove,&nbsp;Michael J. Hickey","doi":"10.1111/micc.70017","DOIUrl":"https://doi.org/10.1111/micc.70017","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>During skin inflammation, inhibition of adhesion of regulatory T cells (Tregs) to the dermal microvascular endothelium leads to exacerbation of inflammation, evidence that the dermal endothelium is a key target of the anti-inflammatory actions of Tregs. The aim of this study was to investigate the capacity of Tregs to control the expression of endothelial adhesion molecules in inflamed and resting skin.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Treg function was assessed in a two-challenge contact hypersensitivity (CHS) model, measuring dermal adhesion molecule expression via imaging of cleared skin. Treg depletion was achieved using <i>Foxp3</i>^<i>DTR</i> mice.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>CHS induced upregulation of E-selectin and ICAM-1 but not P-selectin and VCAM-1. Elimination of Tregs following CHS challenge resulted in exacerbated skin inflammation and enhanced expression of E-selectin, P-selectin and ICAM-1 in the dermal microvasculature. Multiphoton imaging revealed that at this phase of the response, Tregs were enriched near blood vessels and underwent dynamic migration adjacent to the microvasculature. Additionally, in skin that was not undergoing hapten challenge, absence of Tregs also resulted in upregulation of E-selectin and ICAM-1 in skin vessels.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>These observations demonstrate that the microvascular endothelium is a target of the anti-inflammatory actions of Tregs in the skin, both during CHS and in steady-state skin.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.70017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144514649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulatory Role of Nitric Oxide on the Vasomotor Actions of NPY in Porcine Cerebral Arteries","authors":"Gabriela Delgado,&nbsp;Cameron J. Morse,&nbsp;Breanna Barlage,&nbsp;M. Harold Laughlin,&nbsp;Craig A. Emter,&nbsp;Erika M. Boerman,&nbsp;Jaume Padilla,&nbsp;Corey R. Tomczak,&nbsp;T. Dylan Olver","doi":"10.1111/micc.70016","DOIUrl":"https://doi.org/10.1111/micc.70016","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <p>Neuropeptide Y (NPY) is a sympathetic co-transmitter that mediates vasoconstriction. However, there is evidence that it may also mediate dilation through a nitric oxide (NO)-dependent mechanism.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>We used a swine model to examine how NPY influences cerebral vascular regulation and hypothesized that NPY would elicit both vasoconstrictor and vasodilatory effects, and that such effects would be modulated partially by NO signaling.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Briefly, cerebral perfusion and blood pressure were monitored during intracarotid saline or NPY infusion (0.1 μg/kg) in the presence and absence of NO synthase (NOS) inhibition (<i>N</i>^G-nitro-l-arginine methyl ester; 0.35 mg/kg/min). Separately, Y1 receptor distribution (immunohistochemistry) and vasomotor responses to intra- and extraluminal NPY under control and NOS inhibition conditions were examined in isolated arteries.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Intracarotid NPY infusions elicited transient dilation that was blocked by NOS inhibition. In isolated pial arteries, distinct populations of NPY-Y1 receptors were observed on both the vascular smooth muscle (VSM) and endothelium. Extraluminal application of NPY elicited vasoconstriction, while intraluminal delivery elicited vasodilation. NOS inhibition enhanced the magnitude of vasoconstriction in isolated pial arteries. Endothelial denudation, Y1 receptor antagonism, and NOS inhibition each blunted NPY-induced vasodilation.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>These data suggest both vasoconstrictor and vasodilatory effects of NPY are modulated partially by NO signaling.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.70016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Effect of Renal Denervation on Capillary Density in Patients With Uncontrolled Hypertension","authors":"Lefki Nikolopoulou,&nbsp;Kyriakos Dimitriadis,&nbsp;Nikolaos Pyrpyris,&nbsp;Fotios Tatakis,&nbsp;Panagiotis Iliakis,&nbsp;Costas Thomopoulos,&nbsp;Dimitrios Konstantinidis,&nbsp;Loukianos Rallidis,&nbsp;Dimitrios Tousoulis,&nbsp;Konstantinos Tsioufis","doi":"10.1111/micc.70015","DOIUrl":"https://doi.org/10.1111/micc.70015","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>Hypertension is related to the pathogenesis of microvascular dysfunction. Renal denervation is a guideline-endorsed intervention for the management of uncontrolled hypertension. However, the effect of renal denervation on skin capillary density, as assessed by nailfold capillaroscopy, is unknown.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Individuals with stage I/II uncontrolled hypertensions were enrolled and allocated to either undergo renal denervation or serve as controls. Nailfold capillaroscopy was performed at baseline and at 12 months. Furthermore, the albumin to creatinine ratio (ACR) and office/ambulatory blood pressure (BP) levels were monitored throughout the study.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>A total of 45 individuals (28 renal denervation, 17 control) were enrolled in our study. No difference was found in baseline capillary density. At 12 months, all patients had controlled BP, while the denervation arm had a significantly greater number of capillaries, compared with control (90.9 ± 14.0 vs. 82.5 ± 10.6 capillaries/mm²; <i>p</i> = 0.036). However, the change from baseline capillary density was not significantly different between groups (4.6 ± 6.1 vs. 1.39 ± 8.8 capillaries/mm²; <i>p</i> = 0.150). Moreover, the change of ACR was not different between groups (−2.7 ± 13.8 vs. 0.46 ± 5.2; <i>p</i> = 0.365).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>In patients with uncontrolled stage I/II hypertension, renal denervation may have a beneficial effect on skin capillary density.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 5","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/micc.70015","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144339192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical Investigation of Hemodynamic Factors in Cellular Blood Flow: Insights From Curved Microvessels","authors":"Mojtaba Amir Aslan Pour,&nbsp;Wenbin Mao","doi":"10.1111/micc.70013","DOIUrl":"https://doi.org/10.1111/micc.70013","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>This study investigates the effects of hemodynamic factors on blood cell suspension flows and their properties in curved microvessels. A parametric study is employed to compare these properties between curved and straight vessels.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A 3D fluid solver coupled with a cell membrane modeling framework via the immersed boundary method was used to simulate cell-resolved blood flow in straight and curved vessels featuring a 90° bend with moderate curvature.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Blood flow in curved vessels shows lower and higher shear rates in the inner and outer bulk regions, respectively, compared to straight vessels. Asymmetry in hematocrit profiles is linked to less dense suspensions, smaller diameters, and higher Capillary numbers, while the maximum velocity location remains consistent with straight vessels. At physiological shear rates, moderate curvatures, and large diameters, curvature has minimal impact on apparent viscosity. However, diffusivity is elevated at the center of curved vessels compared to straight ones.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>This study reveals new insights into blood suspension flows in curved microvessels with a 90° bend, highlighting key differences from straight vessels under certain hemodynamic conditions. These findings lay the groundwork for future research on realistic microvessel geometries and their implications.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 4","pages":""},"PeriodicalIF":1.9,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144135534","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}