Microvascular research最新文献

{"title":"PCSK9 inhibitor improved cardiac function after acute myocardial infarction in rats","authors":"Hongjin An ,&nbsp;Junju Zhu ,&nbsp;Qianqian Li","doi":"10.1016/j.mvr.2025.104847","DOIUrl":"10.1016/j.mvr.2025.104847","url":null,"abstract":"<div><h3>Background</h3><div>This study investigated the effects and possible mechanisms of Protein expression of protein convertase subtilisin/kexin type 9 (PCSK9) inhibitor evolocumab on cardiac function in rats with acute myocardial infarction (AMI).</div></div><div><h3>Methods</h3><div>The AMI model was established by ligating the left anterior descending coronary artery in rats. The mRNA expression of PCSK9 in myocardial tissues was detected by real-time fluorescent quantitative PCR (RT-qPCR). Echocardiography was used to examine the cardiac function indexes. Hematoxylin-eosin (HE) and Masson stainings were used to detect myocardial pathologic injury. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to detect myocardial infarction area. Serum levels of low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), lactate dehydrogenase (LDH), creatine kinase isoenzymes (CK-MB), cardiac troponin T (cTnT), interleukin-1β (IL-1β), interleukin-17 (IL-17) and tumor necrosis factor-α (TNF-α) were detected by ELISA. CD31 and vascular endothelial growth factor (VEGF) positive expression was detected by immunohistochemistry. Protein expression levels of PCSK9, Bax, Bcl-2, cleaved-caspase3, receptor interacting protein kinase 1 (RIPK1), RIPK3, mixed lineage kinase domain-like (MLKL), and p-MLKL were detected in myocardial tissues by western blot.</div></div><div><h3>Results</h3><div>The mRNA level and protein expression of PCSK9 were significantly increased in AMI rats. PCSK9 inhibitor evolocumab reduced the levels of LDL-C and TC in serum, thereby improving dyslipidemia. And, evolocumab up-regulated the levels of left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS), and down-regulated the levels of left ventricular end systolic diameter (LVESD), left ventricular end diastolic diameter (LVEDD), left ventricular end systolic volume (LVESV), and left ventricular end diastolic volume (LVEDV), which in turn improved cardiac function. In addition, evolocumab attenuated myocardial pathological injury, reduced myocardial infarction area, lowered the levels of LDH, CK-MB, cTnT, IL-1β, IL-17, and TNF-α, and inhibited apoptosis rate, down-regulated Bax, cleaved-caspase3, RIPK1, RIPK3, MLKL, p-MLKL expression, and up-regulated Bcl-2 protein expression, CD31 and VEGF positive expression.</div></div><div><h3>Conclusion</h3><div>The PCSK 9 inhibitor evolocumab improved cardiac function in AMI rats, and the mechanism may be related to the RIPK1/RIPK3/MLKL pathway.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"162 ","pages":"Article 104847"},"PeriodicalIF":2.7,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144718116","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":"Novel in vivo porcine models of chronic ischemic tissue","authors":"Veronika Frelichova ,&nbsp;Robert Bem ,&nbsp;Jaroslav Chlupac ,&nbsp;Michal Dubsky ,&nbsp;Jitka Husakova ,&nbsp;Andrea Nemcova ,&nbsp;Ludek Voska ,&nbsp;Zuzana Simunkova ,&nbsp;Filip Tichanek ,&nbsp;Jiri Fronek","doi":"10.1016/j.mvr.2025.104845","DOIUrl":"10.1016/j.mvr.2025.104845","url":null,"abstract":"<div><div>There is a lack of reliable in vivo models that replicate limb-threatening ischemia in humans. To fill this gap, we developed and validated two novel porcine ischemic models: ischemic limb and dorsal flap models, both with and without streptozotocin-induced hyperglycemia (<em>N</em> = 3 per group, 12 in total). Hind limb ischemia model was induced via different arterial ligations, with two ischemic and three control wounds per animal. In the flap model, four full-thickness flaps were created on the dorsum with silicone sheets to block reperfusion, and excisional wounds were made on the top. One non-ischemic wound served as control. Transcutaneous oxygen pressure (TcPO₂), wound area, and microvascular density were measured, with TcPO₂ and wound area assessed longitudinally. Data analysis focused on detailed visualization and Bayesian hierarchical modelling to account for the small sample size. Developed models exhibited stable ischemia and prolonged wound healing, with TcPO₂ remaining under 30 mmHg over 28 days, and wound healing extending beyond two weeks. The flap model showed slower TcPO₂ recovery and greater chronicity compared to the limb model, without reliable effect of hyperglycemia. Thus, the porcine flap model shows the highest potential as a relevant model for chronic limb-threatening ischemia.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104845"},"PeriodicalIF":2.9,"publicationDate":"2025-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144682787","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":"Evaluation of neovascularization in murine osteoarthritis using micro-computed tomography","authors":"Reza Talaie,&nbsp;Pooya Torkian,&nbsp;Anthony Spano,&nbsp;Alexander Clayton,&nbsp;Jafar Golzarian","doi":"10.1016/j.mvr.2025.104844","DOIUrl":"10.1016/j.mvr.2025.104844","url":null,"abstract":"<div><h3>Purpose</h3><div>The study aimed to examine neovascularization in murine osteoarthritis (OA) using micro-computed tomography (μCT).</div></div><div><h3>Materials and methods</h3><div>OA was induced in eighteen mice through intra-articular collagenase injection, designating the left hindlimbs as OA models and the right hindlimbs as controls. Mice were monitored for 4, 8, or 12 weeks post-induction. Hindlimbs underwent overnight tissue fixation and were then subjected to μCT scanning. Quantification of unnamed arterial branches spanned from the femoral artery's terminal branching point to 2.5 mm below the tibial plateau.</div></div><div><h3>Results</h3><div>Baseline characteristics did not differ significantly between control and OA-induced groups (p &gt; 0.05). Collagenase-treated limbs showed a significantly higher number of unnamed arterial branches compared to controls (11.6 vs. 7.5, p &lt; 0.001), reflecting increased neovascularization. This elevation persisted across all post-induction time points, with no significant time-dependent trend (p = 0.09) or interaction between time and treatment group (p = 0.17). Spatial analysis revealed that neovessels were predominantly localized to peri-meniscal (61 %) and subchondral (29 %) regions.</div></div><div><h3>Conclusion</h3><div>Collagenase-induced OA in mice results in sustained and spatially patterned neovascularization, detectable using non-contrast μCT. These findings underscore the utility of μCT for tracking vascular remodeling in OA and highlight potential anatomical targets for angiogenesis-modulating therapies.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104844"},"PeriodicalIF":2.9,"publicationDate":"2025-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144667978","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":"The electrophysiological effects of angiotensin 1–7 on hypertrophic myocardium in spontaneously hypertensive rats","authors":"Xin Yu ,&nbsp;Zhen Yang ,&nbsp;Zhilan Ma ,&nbsp;Ru Yan ,&nbsp;Jianzhong Zhang","doi":"10.1016/j.mvr.2025.104843","DOIUrl":"10.1016/j.mvr.2025.104843","url":null,"abstract":"<div><div>This study aimed to explore the effects of Angiotensin 1–7 (Ang1–7) on electrophysiological remodeling of hypertensive hypertrophic myocardium in spontaneously hypertensive rats (SHR). Thirty male SHR rats were equally divided into three groups: SHR control group (SHR<img>C) treated with saline; Ang1–7 group (SHR-A) treated with Ang1–7[25 μg·(kg min)⁻¹] and Ang1–7 blocker group (SHR<img>B) treated with A779 [72 μg·(kg min)⁻¹]. Wistar-Kyoto (WKY) rats (<em>n</em> = 10) were used as a normotensive group. The treatment period was 5 weeks. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured. Echocardiography was used to evaluate cardiac function. The ventricular myocytes were isolated for evaluation of electrophysiological remodeling of myocardium using microelectrode and patch clamp techniques. When compared with those in WKY rats before treatment, systolic and diastolic pressures were significantly higher in SHR (<em>P</em> &lt; 0.01 and <em>P</em> &lt; 0.001 respectively), left ventricular end-diastolic diameter (LVEDd) was significantly lower (<em>P</em> &lt; 0.05), while diastolic interventricular septum thickness (IVSd), diastolic left ventricular posterior wall thickness (LVPWd) were significantly greater in SHR (<em>P</em> &lt; 0.01). After 5 weeks of treatment, compared with SHR-C group, SBP, DBP, IVSd, LVPWd in SHR-A group were lower significantly (<em>P</em> &lt; 0.05), while SBP in SHR-B group was significantly higher (<em>P</em> &lt; 0.05). Compared with WKY group, the resting potential (RP), action potential amplitude (APA) and transient sodium current (<em>I</em>_Na-T) in SHR group were significantly lower (<em>P</em> &lt; 0.05), and the action potential duration (APD₂₀, APD₅₀ and APD₉₀) in SHR group was greater (<em>P</em> &lt; 0.05). After Ang1–7 intervention, RP, APA and <em>I</em>_Na-T were significantly greater in SHR-A than those in SHR-C (<em>P</em> &lt; 0.05), and APD in SHR-A significantly lower than that in SHR-C (<em>P</em> &lt; 0.05). Taken together, these results demonstrated that Ang1–7 can not only decrease the blood pressure, but reverse the myocardial hypertrophy and electrophysiological remodeling as well in SHR rats.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104843"},"PeriodicalIF":2.9,"publicationDate":"2025-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144642932","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":"Acute effects of belt electrode-skeletal muscle electrical stimulation on microvascular responsiveness of the gastrocnemius muscle in healthy young men","authors":"Hajime Tamiya ,&nbsp;Hina Kawashiri ,&nbsp;Toshiaki Miyamoto ,&nbsp;Yuko Kurosawa ,&nbsp;Takafumi Hamaoka ,&nbsp;Atsuhiro Tsubaki","doi":"10.1016/j.mvr.2025.104840","DOIUrl":"10.1016/j.mvr.2025.104840","url":null,"abstract":"<div><h3>Purpose</h3><div>Belt electrode-skeletal muscle electrical stimulation (B-SES) improves muscle strength, mass, and exercise tolerance. However, its effects on skeletal muscle microvascular responsiveness remain unclear. In this study, we investigated the acute effects of a single B-SES session on gastrocnemius microvascular responsiveness in healthy young men.</div></div><div><h3>Methods</h3><div>In this randomized crossover study, 12 healthy young men (mean age: 20.8 ± 1.0 years) underwent two 20-min conditions: electrical stimulation at the sensory threshold (Sham, <em>n</em> = 12) and at the maximum intensity not causing discomfort (B-SES, n = 12). Gastrocnemius metabolic rate (tissue oxygen saturation [StO₂] downslope) and microvascular reperfusion rate (StO₂ upslope) were assessed using near-infrared spectroscopy and a vascular occlusion test.</div></div><div><h3>Results</h3><div>In the B-SES condition, the StO₂ downslope significantly steepened (Pre: −0.15 ± 0.03 %·s⁻¹, Post: −0.20 ± 0.03 %·s⁻¹, <em>p</em> = 0.002). The StO₂ upslope also significantly steepened (Pre: 1.58 ± 0.52 %·s⁻¹, Post: 2.56 ± 0.71 %·s⁻¹, <em>p</em> &lt; 0.001). A significant negative correlation was observed between the StO₂ downslope and StO₂ upslope (<em>r</em> = −0.581, <em>p</em> = 0.047). No significant changes were observed in the Sham condition.</div></div><div><h3>Conclusions</h3><div>A single B-SES session applied to the lower extremity significantly increased gastrocnemius metabolic rate and was associated with enhanced microvascular reperfusion. These findings suggest B-SES may be a useful therapeutic approach to improving microvascular responsiveness, particularly in individuals with limited exercise capacity.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104840"},"PeriodicalIF":2.9,"publicationDate":"2025-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144595548","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":"Letter to the editor: “Pitfalls in the assessment of microcirculation”","authors":"Arnaldo Dubin","doi":"10.1016/j.mvr.2025.104841","DOIUrl":"10.1016/j.mvr.2025.104841","url":null,"abstract":"","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104841"},"PeriodicalIF":2.9,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144572148","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":"Kinetics of thromboxane A2 receptor-driven vascular tone in the cerebral cortex ex vivo","authors":"Simone Woodruff ,&nbsp;Benjamin Zimmerman ,&nbsp;Kevin J. Elk ,&nbsp;Jennifer E. Jenks ,&nbsp;Danica Bojovic ,&nbsp;Anusha Mishra","doi":"10.1016/j.mvr.2025.104835","DOIUrl":"10.1016/j.mvr.2025.104835","url":null,"abstract":"<div><div><em>Ex vivo</em> imaging in acute cortical brain slices is a valuable tool to assess neurovascular coupling and is particularly useful for studying active, local changes in microvascular compartments in isolation from upstream or downstream changes in flow. However, the lack of vascular perfusion pressure <em>ex vivo</em> results in loss of vascular tone, which must be restored prior to experiments to unmask dilatory signals. The thromboxane A2 receptor agonist U46619 is a widely used preconstrictor, yet its dose-response properties and kinetics of action on different vascular segments are not fully known. Here, we characterize the effects of U46619 on cortical arterioles and capillaries in <em>ex vivo</em> slices from rats and mice. Dose response curves tested in acute rat brain slices using 0 to 1000 nM U46619 showed that maximal constriction is reached at ∼300 nM in both arterioles and capillaries. Extended application of 200 nM U46619 (∼66 % maximal dose) over 2 h revealed that, on average, capillaries constrict faster than arterioles in rat brain slices. Cross-species examination in mouse tissue showed that vessels in mouse brain slices respond faster and constrict stronger on average than in rat brain slices, and that mouse capillaries also constrict faster than mouse arterioles. Our observations suggest that near-maximal preconstriction can be achieved in <em>ex vivo</em> experiments using 200–300 nM U46619, with a minimum incubation time of 20 min for studies involving capillaries and at least 30 min for studies involving arterioles.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104835"},"PeriodicalIF":2.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144556874","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":"Influence of isometric RPE-clamp exercise on fatigability, muscle oxygenation dynamics, and microvascular function in healthy young adults","authors":"Minyoung Kwak ,&nbsp;Brian Benitez ,&nbsp;Clara J. Mitchinson ,&nbsp;Erik R. Snell ,&nbsp;Haley C. Bergstrom","doi":"10.1016/j.mvr.2025.104839","DOIUrl":"10.1016/j.mvr.2025.104839","url":null,"abstract":"<div><h3>Purpose</h3><div>This study investigated fatigability, reflected by torque responses and time to task failure (TTF), and time course of muscle oxygenation (SmO₂) dynamics, as well as microvascular function assessed by near-infrared spectroscopy-vascular occlusion test (NIRS-VOT), in response to low-intensity, isometric forearm flexion anchored to a constant rating of perceived exertion (RPE) level of 3 (0–10 scale).</div></div><div><h3>Methods</h3><div>Twenty-five healthy young adults (22.9 ± 4.8 yr) completed a pre-exercise VOT, maximal voluntary isometric contraction (MVIC), and RPE-clamp exercise (RPE = 3), followed by post-exercise MVIC and VOT. Initial torque, TTF, and SmO₂ dynamics were recorded during the RPE-clamp exercise. The time course of SmO₂ was analyzed in 5 % TTF segments. During the VOTs, slope 1 (desaturation rate), minimum SmO₂, slope 2 (reperfusion rate), maximum SmO₂, and area under the curve (AUC) were recorded.</div></div><div><h3>Results</h3><div>MVIC torque significantly decreased from pre- to post-exercise (−13.9 % ± 14.0 %; <em>p</em> &lt; 0.001). Initial torque was 23.3 ± 10.3 % MVIC, and TTF was 436.3 ± 252.0 s. SmO₂ declined significantly from 0 % to 5 % TTF (<em>p</em> = 0.005), but returned to the initial value and remained stable across subsequent time intervals. Compared to pre-VOT, post-VOT exhibited significantly lower slope 1 (<em>p</em> &lt; 0.001) and minimum SmO₂ (<em>p</em> = 0.002), and greater maximum SmO₂ (<em>p</em> = 0.013), while slope 2 (<em>p</em> = 0.065) and AUC (<em>p</em> = 0.379) were unchanged.</div></div><div><h3>Conclusions</h3><div>During the RPE-clamp exercise, the voluntary reduction in torque to maintain the assigned RPE likely resulted in stable muscle oxygen availability, preventing the development of hypoxic stimulus needed to enhance microvascular responsiveness. However, the low-intensity isometric RPE-clamp exercise combined with a post-VOT may enhance muscle aerobic metabolism through sustained oxygen utilization.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104839"},"PeriodicalIF":2.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144548508","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":"Structural and causal links between retinal vascular geometry and neural layer thickness","authors":"Mayinuer Yusufu ,&nbsp;Robert N. Weinreb ,&nbsp;Mengtian Kang ,&nbsp;Algis J. Vingrys ,&nbsp;Xianwen Shang ,&nbsp;Lei Zhang ,&nbsp;Danli Shi ,&nbsp;Mingguang He","doi":"10.1016/j.mvr.2025.104834","DOIUrl":"10.1016/j.mvr.2025.104834","url":null,"abstract":"<div><h3>Purpose</h3><div>To investigate structural relationships between retinal vasculometry from color fundus photography (CFP) and neural layers obtained from Optical Coherence Tomography (OCT) scans.</div></div><div><h3>Methods</h3><div>This cross-sectional study used the Retina-based Microvascular Health Assessment System (RMHAS) to extract retinal vascular measurements in the 6*6 mm area centered on the macular region and analyzed their associations with OCT parameters. We investigated both pairwise correlations between individual retinal layers and vascular parameters and associations between sets of variables. Mendelian randomization was employed to investigate potential causality.</div></div><div><h3>Results</h3><div>Data from 67,918 eyes of 43,029 participants were included. Among neural layers, Ganglion Cell-Inner Plexiform Layer (GC-IPL) showed the most notable correlations with vascular Density and Complexity (<em>r</em> = 0.199 for arterial Vessel Area Density and <em>r</em> = 0.175 for Number of Segments). Inner Nuclear Layer (INL) thickness correlated with Width (<em>r</em> = 0.122) and arterial Vessel Area Density (<em>r</em> = 0.127). Mendelian randomization indicated a bidirectional causal relationship. Genetically predicted higher Vessel Density was associated with increased thickness across various retinal layers, with standardized effect size of 1.50 on Inner Segment/Outer Segment + Photoreceptor Segment thickness. Genetically predicted increases in retinal layer thicknesses, particularly the Outer Plexiform Layer, were linked to higher Vessel Density (standardized effect size 0.45) and Fractal Dimension (standardized effect size 0.48).</div></div><div><h3>Conclusions</h3><div>GC-IPL and INL were positively associated with vascular Density and Caliber. Multidimensional relationships indicate a complementary nature between retinal vascular and neural parameters, highlighting their value as a composite biomarker. Mendelian Randomization uncovered a bidirectional causal relationship, providing insights into novel therapeutic approaches targeting vascular and neuronal components.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104834"},"PeriodicalIF":2.9,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144522807","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":"A theoretical model for oxygen transport to the cerebral cortex: effects of flow redistribution by penetrating arterioles","authors":"Akshita Sharma ,&nbsp;Timothy W. Secomb","doi":"10.1016/j.mvr.2025.104836","DOIUrl":"10.1016/j.mvr.2025.104836","url":null,"abstract":"<div><div>The goal of this study is to analyze the effects of changes of blood flow in penetrating arterioles (PAs) on the spatial distribution of tissue oxygen levels in the cerebral cortex. A theoretical model is used to simulate blood flow and oxygen transport in the cortical microcirculation. Networks containing up to 20,000 vessel segments, covering regions up to 1.1 mm², are generated by combining multiple hexagonal units, each fed by one PA. Varying numbers of adjacent PAs are constricted to 50 % of their original diameters, resulting in PA flow reduction by 93 %. With constriction of one or two PAs, the predicted minimum oxygen partial pressure is in the range 10–20 mmHg, corresponding to mild hypoxia. When three or more adjacent PAs are constricted, severe hypoxia (partial pressure below 10 mmHg) is predicted. Thus, oxygenation of the cortex is predicted to be only mildly affected by flow reduction in isolated PAs, but vulnerable to flow reduction in multiple adjacent PAs. Further simulations are used to explore the effects of flow redistribution while holding overall perfusion constant. If one PA is constricted and one adjacent PA is dilated, mild hypoxia is present. With three PAs constricted and four adjacent PAs dilated, regions of both mild and severe hypoxia are predicted. These results show that redistribution of blood flow, caused for instance by disruption of mechanisms for local blood flow regulation, can result in tissue hypoxia, even in the absence of reduced perfusion.</div></div>","PeriodicalId":18534,"journal":{"name":"Microvascular research","volume":"161 ","pages":"Article 104836"},"PeriodicalIF":2.9,"publicationDate":"2025-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518521","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}