Microcirculation最新文献_第2页

Hydrostatic Pressures in Lymphatic Networks of the Mouse 小鼠淋巴网络中的静水压力。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-12-18 DOI: 10.1111/micc.70046

Michael J. Davis

Objective

Current research on the lymphatic system makes nearly exclusive use of mouse models because that species is highly amenable to genetic manipulation. However, the lack of information about intraluminal hydrostatic pressures in mouse lymphatic networks limits the ability of investigators, for both in vivo and ex vivo studies, to interpret key physiological data. The goal of the present study was to provide some of that information for several commonly studied lymphatic vessel networks of young, healthy mice: the superficial cervical lymphatic network, the popliteal afferent network, and the mesentery network.

Methods

The servo-null micropressure method was used to measure intraluminal hydrostatic pressures in lymphatic vessels, taking advantage of Prox1-GFP and Prox1-tom mice, expressing eGFP and td-tomato reporters, respectively, in lymphatic endothelium, to visualize entire lymphatic networks and facilitate micropuncture of individual vessels.

Results

New methods were devised for making servo-null pressure measurements under fluorescence illumination. Intraluminal pressures oscillated with the lymphatic contraction cycle, and systolic pressure peaks coincided with lymphatic systole. The largest peaks occurred when contractions of consecutive lymphangions were entrained. In networks with active contractions, the pressure profile was “uphill”; in networks without contractions, the pressure profile was “downhill.”

Conclusions

Our results provide essential information about the “normal” values for intraluminal hydrostatic pressures in several of the most commonly studied lymphatic networks of the mouse.

目的：目前对淋巴系统的研究几乎只使用小鼠模型，因为该物种高度易受基因操纵。然而，缺乏关于小鼠淋巴网络腔内静水压力的信息限制了研究人员在体内和离体研究中解释关键生理数据的能力。本研究的目的是为年轻健康小鼠常用的几种淋巴管网络提供一些信息：颈浅淋巴管网络、腘窝传入网络和肠系膜网络。方法：利用分别表达eGFP和td-tomato报告基因的Prox1-GFP和Prox1-tom小鼠，采用伺服零微压法测量淋巴管腔内静水压力，在淋巴管内皮中显示整个淋巴网络，方便对单个血管进行微穿刺。结果：设计了荧光照明下伺服零压力测量的新方法。腔内压力随淋巴收缩周期振荡，收缩压峰值与淋巴收缩一致。最大的峰值发生在连续的淋巴管收缩时。在主动收缩的网络中，压力剖面为“上坡”；在没有收缩的网络中，压力分布是“下坡的”。“结论：我们的结果提供了关于小鼠几个最常研究的淋巴网络的腔内静水压力“正常”值的基本信息。

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引用次数: 0

Maternal Apocynin During Experimental Preeclampsia Prevents BBB Permeability and Increased Vascular Tone of Cerebral Arteries in Male but Not Female Rat Adult Offspring 实验性子痫前期母鼠罗布麻素对雄性大鼠成年后代血脑屏障通透性和脑动脉血管张力的抑制作用，但对雌性大鼠成年后代无抑制作用。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-12-17 DOI: 10.1111/micc.70044

Milena Esposito, Sarah M. Tremble, Marilyn J. Cipolla

Objective

We examined if exposure to experimental preeclampsia (ePE) impacts vascular permeability and reactivity of posterior cerebral arteries (PCAs) in adult offspring, and if maternal antioxidant treatment prevents these effects in adult male and female offspring.

Methods

Offspring (F1) from rats with Normal pregnancy (NormPreg_F1), ePE_F1 and ePE treated with apocynin (ePE + apo_F1) were weighed at p24, p31, p38, and p45. Maternal apocynin was administered weekly in drinking water at a dose of ∼24 mg/kg (3 mM) on gestational days 11–20. Blood–brain barrier (BBB) permeability, structure and function of PCAs were measured from male and female adult offspring (n = 8/group, 12–29 weeks). Circulating inflammatory factors were measured by multiplex array.

Results

Male ePE_F1 had smaller body weights than male NormPreg_F1 (p < 0.05) at all ages which was prevented by maternal apocynin. Female ePE_F1 body weights were less only at p24 which was prevented by maternal apocynin. PCAs from male ePE_F1 had increased BBB permeability versus male NormPreg_F1 which was prevented by apocynin (p < 0.05). These changes were not seen in female ePE_F1s. Maternal ePE did not affect PCA reactivity to inward potassium rectifier channel or voltage-operated calcium channel activation, nor reactivity to L-NAME and sodium nitroprusside. There were little differences in plasma inflammatory factors.

Conclusions

ePE exposure had long-term consequences on the cerebral circulation of adult male offspring. Understanding the underlying mechanism by which PE adversely impacts the brain of offspring may lead to the prevention of cognitive decline and stroke in adulthood.

目的：研究实验性子痫前期（ePE）暴露是否会影响成年后代的血管通透性和脑后动脉（PCAs）的反应性，以及母体抗氧化治疗是否会阻止成年雄性和雌性后代的这些影响。方法：对正常妊娠大鼠（NormPreg_F1）、ePE_F1和经夹心素处理的ePE （ePE + apo_F1）的子代（F1）在p24、p31、p38和p45称重。在妊娠11-20天，每周在饮用水中给予母亲罗布麻素，剂量为~ 24 mg/kg （3 mM）。测定雄性和雌性成年后代血脑屏障（BBB）的通透性、结构和功能（n = 8/组，12-29周）。采用多重阵列法检测循环炎症因子。结论：ePE暴露对成年雄性后代的脑循环有长期影响。了解体育运动对后代大脑产生不利影响的潜在机制，可能有助于预防成年后的认知能力下降和中风。

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引用次数: 0

Microvascular Reactivity to Cutaneous Local Heating in the Paretic and Non-Paretic Legs of Chronic Stroke Survivors—A Pilot Study 慢性中风幸存者下肢麻痹和非麻痹对皮肤局部加热的微血管反应性——一项初步研究

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-12-17 DOI: 10.1111/micc.70036

Amanda E. Wietrzny, Austen R. Schweinert, Gabriel R. Merkow, Jennifer N. Nguyen, Alicen A. Whitaker-Hilbig, Allison S. Hyngstrom, Matthew J. Durand

Objective and Hypothesis

Cutaneous microvascular reactivity was investigated in chronic stroke survivors by comparing vasodilatory responses in the paretic and non-paretic legs to matched controls. It was hypothesized that vasodilatory responses would be blunted in the paretic leg of stroke survivors vs. the non-paretic leg and controls.

Methods

Cutaneous vascular conductance to local heating was measured in 20 stroke survivors and 20 controls using laser-Doppler flowmetry probes with integrated heaters. Probes were placed on both legs of stroke survivors and the dominant leg of controls. After 15 min rest, the skin was subjected to gradual (1°C/5 min) or rapid heating (0.1°C/s) to 39°C, then increased to 43°C to induce maximal vasodilation.

Results

Vasodilation to gradual heating did not differ between the paretic and non-paretic legs of stroke survivors (p = 0.07) and controls (p = 0.82). Neurogenic axon-mediated responses to rapid heating showed no differences across groups (paretic vs. non-paretic, p = 1.00; paretic vs. control, p = 0.23).

Conclusion

Cutaneous vasodilatory responses to gradual and rapid heating were comparable between stroke survivors and controls. Future studies combining local heating with dermal microdialysis should explore specific vasodilatory pathways, as limb-specific changes may not be evident by measuring vasodilatory magnitude alone.

目的和假设：通过比较麻痹性和非麻痹性腿与匹配对照组的血管舒张反应，研究慢性中风幸存者的皮肤微血管反应性。据推测，中风幸存者的瘫腿与非瘫腿和对照组相比，血管舒张反应会减弱。方法：采用集成加热器的激光多普勒血流仪测量20例脑卒中幸存者和20例对照者局部加热时的皮肤血管传导。探针被放置在中风幸存者的双腿和对照组的主腿上。休息15分钟后，皮肤逐渐（1°C/5 min）或快速加热（0.1°C/s）至39°C，然后升高至43°C以诱导最大血管舒张。结果：血管舒张到逐渐升温在中风幸存者的麻痹性和非麻痹性腿与对照组之间没有差异（p = 0.07）。神经源性轴突介导的快速加热反应在各组之间没有差异（双亲病与非双亲病，p = 1.00；双亲病与对照组，p = 0.23）。结论：在脑卒中幸存者和对照组之间，逐渐和快速加热的皮肤血管舒张反应是相似的。未来结合局部加热和皮肤微透析的研究应该探索特定的血管舒张途径，因为仅通过测量血管舒张幅度可能无法显示肢体特异性变化。

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引用次数: 0

Microcirculation From Head to Toe 从头到脚微循环。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-12-08 DOI: 10.1111/micc.70037

Liping Zhang, Stephen T. Hammond, Julie Leonard-Duke, Galina Yu. Mironova, Reetu Singh, Sonia Taib, Nien-Wen Wu, Janaka Senarathna, Jamie E. Meegan

引用次数: 0

The Comparative Validity of the Sublabial Fossa to the Sublingual Triangle in Sidestream Dark Field Videomicroscopy for Measuring Microcirculatory Parameters 侧流暗场视频显微镜测量微循环参数的唇下窝与舌下三角的比较有效性。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-12-04 DOI: 10.1111/micc.70038

Trent Payne, Ryan Homes, Raushan Lala, Ruth E. Hubbard, Mark Midwinter

Objective

This study compared microcirculatory measures using sidestream dark field (SDF) videomicroscopy at sublingual and sublabial regions, examining whether novice examiners can achieve comparable reliability to experienced operators and the effect of operator experience on sublabial image quality.

Methods

Microcirculatory imaging was performed using SDF videomicroscopy at the sublingual and sublabial regions. Sublingually, the probe was placed under the tongue on the mucosa of the floor of the mouth, in a stable, flat position to minimize tissue distortion. Sub-labially, the probe was positioned on the mucosa medial to the superior labial frenulum and stabilized between the central and lateral incisors. Participants were positioned at a 40-degree incline. Both novice and experienced operators captured images, and manually analyzed clips in AVA 3.2 software. All images were evaluated using the microcirculatory image quality score. Total vessel density, perfused vessel density, portion of perfused vessels, microvascular flow index, and heterogeneity index were calculated.

Results

No statistically significant differences in image quality scores were found between observers at the sublabial site. Vessel density measures demonstrated reliable inter-observer agreement, while some flow indices showed proportional bias (MFI, p = 0.01). No significant differences were detected between sublingual and sublabial regions for most measures, except for the microvascular flow index.

Conclusions

The sublabial site is a valid alternative to the sublingual region for measuring certain microcirculatory parameters, though it requires further evaluation in flow metrics.

目的：本研究比较了侧流暗场（SDF）视频显微镜在舌下和下唇区域的微循环测量，考察新手检查人员是否能达到与经验丰富的操作人员相当的可靠性，以及操作人员经验对下唇图像质量的影响。方法：采用SDF视频显微镜对舌下和下唇区进行微循环成像。舌下将探针置于舌下，置于口腔底部粘膜上，处于稳定、平坦的位置，以尽量减少组织变形。唇下探针位于唇上系带内侧的粘膜上，稳定在中切牙和侧切牙之间。参与者被安排在一个40度的倾斜位置。新手和经验丰富的操作员都可以捕获图像，并在AVA 3.2软件中手动分析片段。使用微循环图像质量评分对所有图像进行评估。计算血管总密度、灌注血管密度、灌注血管比例、微血管流动指数、非均质性指数。结果：观察者在下颚部位的图像质量评分无统计学差异。血管密度测量显示出可靠的观察者间一致性，而一些流量指数显示出比例偏差（MFI, p = 0.01）。除了微血管流动指数外，舌下和下唇区域在大多数测量中没有显著差异。结论：唇下部位是测量某些微循环参数的有效替代方法，尽管它需要进一步的血流指标评估。

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引用次数: 0

AP-1 Is an Initial Convergent Transcriptional Response in Lymphatic Endothelium to VEGF-C or TNFα AP-1是淋巴内皮对VEGF-C或tnf - α的初始趋同转录反应。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-11-24 DOI: 10.1111/micc.70035

Ewa A. Kreft, Zuzanna J. Juśkiewicz, Brant E. Isakson

Objective

The lymphatic vasculature plays a central role in resolving inflammation by draining interstitial fluid, immune cells, and inflammatory mediators. While vascular endothelial growth factor C (VEGF-C) is a well-established driver of lymphangiogenesis, the effects of chronic pro-inflammatory cytokines on lymphatic remodeling remain incompletely defined.

Methods

Here, we investigated how tumor necrosis factor alpha (TNFα) compares with VEGF-C in regulating lymphatic endothelial structure and function using human dermal lymphatic endothelial cells (HDLECs).

Results

In tube formation and spheroid sprouting assays, both VEGF-C and TNFα supported early lymphangiogenic events, promoting robust sprouting and network development within 24 h. However, when pre-formed microvascular networks were challenged, prolonged TNFα exposure triggered progressive destabilization, characterized by tube fragmentation, reduced proliferation, and impaired metabolic activity, whereas VEGF-C preserved network stability. Mechanistically, both VEGF-C and TNFα induced rapid phosphorylation of p38 MAPK and upregulation of Activator Protein-1 (AP-1) transcription factor subunits within 30 min, suggesting a convergent early transcriptional response. Bulk RNA-sequencing confirmed shared induction of AP-1 family genes (FOS, JUN, ATF), highlighting AP-1 as a candidate regulator of the transition between adaptive and maladaptive outcomes. We propose that transient AP-1 activation promotes pro-lymphangiogenic programs, while sustained TNFα signaling redirects AP-1 activity toward stress, growth arrest, and apoptosis, leading to lymphatic regression.

Conclusion

These findings identify TNFα as a temporally bifunctional regulator of lymphatic endothelial fate.

目的：淋巴血管系统通过引流间质液、免疫细胞和炎症介质，在解决炎症中起核心作用。虽然血管内皮生长因子C （VEGF-C）是淋巴管生成的一个公认的驱动因素，但慢性促炎细胞因子对淋巴管重塑的影响仍不完全明确。方法：利用人真皮淋巴内皮细胞（HDLECs），比较肿瘤坏死因子α (TNFα)与VEGF-C对淋巴内皮结构和功能的调节作用。结果：在试管形成和球形发芽试验中，VEGF-C和tnf - α都支持早期淋巴管生成事件，促进24小时内稳健的发芽和网络发育。然而，当预先形成的微血管网络受到挑战时，长时间的TNFα暴露会引发进行性不稳定，其特征是管断裂、增殖减少和代谢活性受损，而VEGF-C则保持了网络的稳定性。在机制上，VEGF-C和tnf - α在30分钟内诱导p38 MAPK的快速磷酸化和激活蛋白1 （AP-1）转录因子亚基的上调，表明早期转录反应趋同。大量rna测序证实了AP-1家族基因（FOS， JUN， ATF）的共同诱导，强调AP-1是适应和不适应之间转变的候选调节因子。我们认为，短暂的AP-1激活促进了前淋巴管生成程序，而持续的tnf - α信号将AP-1活性重定向到应激、生长停滞和细胞凋亡，导致淋巴管退化。结论：这些发现确定TNFα是淋巴内皮命运的暂时性双功能调节剂。

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引用次数: 0

Immersion-Based Clearing and Autofluorescence Quenching in Myocardial Tissue 心肌组织浸泡清除和自身荧光猝灭。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-11-05 DOI: 10.1111/micc.70034

Victoria E. Sturgess, Nadia K. Korovesis, Domingo E. Uceda, Ali Citalan-Madrid, Eric V. Vu, Katherine Stangis, Françoise Van den Bergh, Salman I. Essajee, Binyamin Jacobovitz, Gregory B. Sands, Daniel A. Lawrence, Johnathan D. Tune, Daniel A. Beard, Geoffrey G. Murphy, C. Alberto Figueroa

Objective

Recent innovations in optical microscopy and tissue preparation permit 3D visualization of complex microvascular networks. Tissue clearing techniques improve light penetration and extend imaging depth. Typically, perfusion-based approaches are used for vascular labeling and tissue clearing. However, immersion-based methodologies provide enhanced practicality when processing tissues from larger animal models.

Methods

We present an immersion-based microvascular labeling and tissue clearing protocol for myocardial tissues using tomato lectin and CUBIC (Clear, Unobstructed Brain/Body Imaging Cocktails and Computational analysis), demonstrating success for imaging depths of up to 150 μm. This protocol optimized the delipidation and quenching stages for rat and pig myocardial tissues. Image quality was assessed using an automated analysis of signal-to-noise ratios (SNR) and average z-slice intensities.

Results

Optimal image quality was obtained with 24-h CUBIC Reagent I incubation times. Quenching agents TrueVIEW, Glycine, and Trypan Blue did not significantly impact SNR values. TrueBlack and Sudan Black B showed trends of reduced imaging depth compared to controls without quencher incubation. Overall, rat myocardial tissues had higher SNRs than pig tissue samples.

Conclusions

This protocol provides a rigorous foundation for the optimization of immersion-based approaches for myocardial tissue clearing. Future studies will quantify anatomical and topological coronary microvascular to compare disease states.

目的：最近在光学显微镜和组织制备方面的创新使得复杂微血管网络的三维可视化成为可能。组织清除技术提高光穿透和扩展成像深度。通常，基于灌注的方法用于血管标记和组织清除。然而，基于浸泡的方法在处理大型动物模型的组织时提供了增强的实用性。方法：我们提出了一种基于浸泡的心肌组织微血管标记和组织清除方案，使用番茄凝集素和CUBIC（清晰，无阻碍的脑/体成像鸡尾酒和计算分析），证明了成像深度高达150 μm的成功。本方案优化了大鼠和猪心肌组织的脱脂和猝灭阶段。使用信噪比（SNR）和平均z片强度的自动分析来评估图像质量。结果：CUBIC Reagent I孵育时间为24 h，图像质量最佳。猝灭剂TrueVIEW、甘氨酸和台锥蓝对信噪比值没有显著影响。TrueBlack和苏丹黑B与没有淬灭剂孵育的对照组相比，显示出成像深度降低的趋势。总体而言，大鼠心肌组织的信噪比高于猪组织样本。结论：该方案为优化浸入式心肌组织清除方法提供了严格的基础。未来的研究将量化解剖和拓扑冠状动脉微血管来比较疾病状态。

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引用次数: 0

CaMKII Antagonism Improves Vascular Dysfunction in the Visceral Adipose Microvasculature of Obese Subjects CaMKII拮抗剂改善肥胖受试者内脏脂肪微血管的血管功能障碍

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-10-23 DOI: 10.1111/micc.70033

Bulbul Ahmed, Melissa G. Farb, Sophia D'Alessandro, Luise Pernar, Brain Carmine, Donald T. Hess, Kenneth Walsh, Noyan Gokce

Objective

We have previously demonstrated angiogenic impairment, inflammation, and endothelial vasomotor dysfunction in the visceral adipose vasculature of obese individuals. Here, we investigated the role of calcium/calmodulin-dependent protein kinase II (CaMKII) in the regulation of vascular phenotype in the adipose microvasculature.

Methods

Using visceral and subcutaneous fat specimens biopsied from obese subjects (BMI 48 ± 9 kg/m², age 38 ± 11 years), we examined the effect of CaMKII antagonism on acetylcholine-mediated, endothelium-dependent vasodilation of isolated arterioles using videomicroscopy and studied angiogenic capillary sprouting capacity ex vivo.

Results

Pharmacological inhibition of CaMKII with KN-93 improved endothelium-dependent vasodilation of isolated visceral arterioles by 3-fold (p < 0.001 vs. control) and increased visceral fat sprouting capacity by 2.5-fold (p < 0.001). Inhibition of endothelial nitric oxide synthase with N(ω)-nitro-l-arginine methyl ester blunted KN-93-induced improvements in vasodilation and angiogenesis, suggesting dependence on increased nitric oxide bioavailability. KN-93 had no effect on subcutaneous angiogenic capacity, which exhibited preserved angiogenic growth compared to visceral fat. KN-93 exposure was associated with reduced reactive oxygen species generation and decreased vascular gene expression of JUN, NFAT5, and CAMKII signaling components.

Conclusion

Our findings suggest that CaMKII signaling may negatively modulate microvascular function, contribute to increased oxidative stress, and pro-inflammation observed in the visceral adipose microenvironment in obesity.

目的：我们之前已经证明肥胖个体的内脏脂肪血管存在血管生成障碍、炎症和内皮血管舒缩功能障碍。在这里，我们研究了钙/钙调素依赖性蛋白激酶II （CaMKII）在脂肪微血管血管表型调节中的作用。方法：利用肥胖受试者（BMI 48±9 kg/m2，年龄38±11岁）的内脏和皮下脂肪标本，通过视频显微镜观察CaMKII拮抗剂对乙酰胆碱介导的内皮依赖性离体小动脉血管舒张的影响，并研究血管生成毛细血管的离体发芽能力。结论：我们的研究结果表明，CaMKII信号可能负向调节微血管功能，促进氧化应激的增加，并在肥胖的内脏脂肪微环境中观察到促炎症。

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引用次数: 0

Observational Study of Sublingual Microcirculation in Patients With Chronic Cardiovascular Disease 慢性心血管疾病患者舌下微循环的观察研究。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-10-13 DOI: 10.1111/micc.70032

Jacob Niculcea, James W. Schurr, Fatima M. Talebi, Joyce W. Wald, John C. Greenwood

Background

Sublingual video microscopy is increasingly used to study the microcirculation in acute illness. However, the sublingual microcirculation in patients with chronic cardiovascular diseases (CVD) is understudied. Our objective was to quantify sublingual microcirculatory parameters in a large cohort of patients with CVD.

Methods

One hundred and thirteen patients with CVD were enrolled. Incident dark-field handheld video microscopy (IDF-HVM) was used to quantify microvascular flow index (MFI), microvascular heterogeneity index (MHI), proportion of perfused vessels (PPV), perfused vessel density (PVD), and total vessel density (TVD). Data were stratified by age quartiles (20–39, 40–59, 60–79, 80+), cardiovascular comorbidities (hypertension, diabetes, chronic kidney disease, coronary artery disease, heart failure), and systemic hemodynamics (mean arterial pressure and pulse pressure).

Results

In our 113 patient cohort, overall MFI = 2.86 ± 0.20; MHI = 0.15 ± 0.20; PPV = 94.3% ± 4.9%; PVD = 23.1 ± 4.7 mm/mm²; and TVD = 24.5 ± 4.8 mm/mm². Diabetic patients had lower mean MHI (0.10 vs. 0.17; p = 0.046) compared to those without diabetes. There was no difference in sublingual parameters attributable to other CVDs, age, or hemodynamics.

Conclusion

In patients with stable cardiovascular disease, sublingual microvascular parameters are similar across age, blood pressure, and comorbidity cohorts, with the exception of decreased MHI in diabetic patients.

背景：舌下视频显微镜越来越多地用于研究急性疾病的微循环。然而，慢性心血管疾病（CVD）患者的舌下微循环尚未得到充分研究。我们的目的是量化一大群CVD患者的舌下微循环参数。方法：纳入113例CVD患者。采用入射暗场手持式视频显微镜（IDF-HVM）对微血管流动指数（MFI）、微血管异质性指数（MHI）、灌注血管比例（PPV）、灌注血管密度（PVD）、总血管密度（TVD）进行量化。数据按年龄四分位数（20-39岁、40-59岁、60-79岁、80岁以上）、心血管合并症（高血压、糖尿病、慢性肾病、冠状动脉疾病、心力衰竭）和全身血流动力学（平均动脉压和脉压）进行分层。结果：在113例患者队列中，总体MFI = 2.86±0.20；mhi = 0.15±0.20；ppv = 94.3%±4.9%；PVD = 23.1±4.7 mm/mm2；TVD = 24.5±4.8 mm/mm2。与非糖尿病患者相比，糖尿病患者的平均MHI较低（0.10 vs. 0.17; p = 0.046）。其他心血管疾病、年龄或血流动力学引起的舌下参数没有差异。结论：在稳定性心血管疾病患者中，除了糖尿病患者的MHI降低外，舌下微血管参数在年龄、血压和合并症队列中相似。

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引用次数: 0

Effects of Different Isometric Exercise Modalities on Microvascular and Metabolic Function 不同等长运动方式对微血管和代谢功能的影响。

IF 2 4区医学 Q3 HEMATOLOGY

Microcirculation

Pub Date : 2025-10-13 DOI: 10.1111/micc.70031

Minyoung Kwak, Brian Benitez, Clara J. Mitchinson, Erik R. Snell, Haley C. Bergstrom

Objective

This study compared near-infrared spectroscopy (NIRS)-derived microvascular function, muscle oxygenation (SmO₂) dynamics, and fatigability during sustained isometric forearm flexion under two conditions: a rating of perceived exertion (RPE) level of 3 (RPE-Clamp) versus a constant torque (CT) matched to the torque produced during the first second of RPE-Clamp.

Methods

Thirteen healthy males (22.2 ± 4.7 year) completed both tasks on separate days. SmO₂ was measured during exercise, maximal voluntary isometric contractions (MVIC) were performed before and after exercise, and time to task failure (TTF) was recorded. Vascular occlusion tests (VOT) were used to assess microvascular function pre- and post-exercise.

Results

CT induced significantly greater performance fatigability than RPE-Clamp (p < 0.001), despite similar TTF (p = 0.171). SmO₂ significantly decreased during early (p = 0.001) and final (p = 0.028) phases of CT, while increasing during mid (p < 0.001) phases in RPE-Clamp. Post-VOT indicated a significantly reduced desaturation rate (slope 1; p < 0.001), a greater extent of tissue hypoxia (minimum SmO₂; p = 0.003), and increased microvascular reactivity (slope 2; p = 0.021) than pre-VOT, with greater peak re-saturation (MaxSmO₂; p = 0.010) observed in CT than RPE-Clamp.

Conclusions

Despite greater fatigability and desaturation in CT, both exercise modalities may enhance microvascular reactivity. Prolonged isometric exercise and subsequent hypoxic stress may contribute to a reduced desaturation rate post-exercise.

目的：本研究比较了近红外光谱（NIRS）衍生的微血管功能、肌肉氧合（SmO2）动力学和持续等距前臂屈曲在两种情况下的疲劳程度：感知用力（RPE）等级为3 （RPE- clamp）与恒定扭矩（CT）相匹配的RPE- clamp第一秒产生的扭矩。方法：13名健康男性（22.2±4.7岁）在不同的日期完成两项任务。运动时测量SmO2，运动前后测量最大自主等长收缩（MVIC），记录任务失败时间（TTF）。血管闭塞试验（VOT）用于评估运动前后微血管功能。结果：CT诱导的疲劳性能明显高于RPE-Clamp (p值在CT早期（p = 0.001）和末期（p = 0.028）降低，在CT中期（p值p = 0.003）升高，微血管反应性（斜率2；p = 0.021）高于vot前，峰值再饱和度（MaxSmO2; p = 0.010）高于RPE-Clamp。结论：尽管CT表现出更大的疲劳和去饱和，但两种运动方式都可以增强微血管反应性。长时间的等长运动和随后的低氧应激可能有助于降低运动后的去饱和率。

{"title":"Effects of Different Isometric Exercise Modalities on Microvascular and Metabolic Function","authors":"Minyoung Kwak, Brian Benitez, Clara J. Mitchinson, Erik R. Snell, Haley C. Bergstrom","doi":"10.1111/micc.70031","DOIUrl":"10.1111/micc.70031","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>This study compared near-infrared spectroscopy (NIRS)-derived microvascular function, muscle oxygenation (SmO<sub>2</sub>) dynamics, and fatigability during sustained isometric forearm flexion under two conditions: a rating of perceived exertion (RPE) level of 3 (RPE-Clamp) versus a constant torque (CT) matched to the torque produced during the first second of RPE-Clamp.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Thirteen healthy males (22.2 ± 4.7 year) completed both tasks on separate days. SmO<sub>2</sub> was measured during exercise, maximal voluntary isometric contractions (MVIC) were performed before and after exercise, and time to task failure (TTF) was recorded. Vascular occlusion tests (VOT) were used to assess microvascular function pre- and post-exercise.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>CT induced significantly greater performance fatigability than RPE-Clamp (<i>p</i> < 0.001), despite similar TTF (<i>p</i> = 0.171). SmO<sub>2</sub> significantly decreased during early (<i>p</i> = 0.001) and final (<i>p</i> = 0.028) phases of CT, while increasing during mid (<i>p</i> < 0.001) phases in RPE-Clamp. Post-VOT indicated a significantly reduced desaturation rate (slope 1; <i>p</i> < 0.001), a greater extent of tissue hypoxia (minimum SmO<sub>2</sub>; <i>p</i> = 0.003), and increased microvascular reactivity (slope 2; <i>p</i> = 0.021) than pre-VOT, with greater peak re-saturation (MaxSmO<sub>2</sub>; <i>p</i> = 0.010) observed in CT than RPE-Clamp.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>Despite greater fatigability and desaturation in CT, both exercise modalities may enhance microvascular reactivity. Prolonged isometric exercise and subsequent hypoxic stress may contribute to a reduced desaturation rate post-exercise.</p>\u0000 </section>\u0000 </div>","PeriodicalId":18459,"journal":{"name":"Microcirculation","volume":"32 7","pages":""},"PeriodicalIF":2.0,"publicationDate":"2025-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145280618","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}

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