Microcirculation : the Official Journal of the Microcirculatory Society, Inc

No abstract text is available yet for this article.

OBJECTIVE: To determine if insulin mediated hyperemia is partially dependent on local muscle oxygen concentration. METHODS: Sprague-Dawley rats were anesthetized, and the extensor digitorum longus (EDL) was reflected onto an inverted microscope. Intravital video microscopy sequences were recorded during baseline and hyperinsulinemic euglycemia. The muscle was reflected over a glass stage insert (Experiment 1a and 1b), or over a gas exchange chamber (Experiment 2), and microvascular capillary blood flow was recorded during sequential changes (7%-12%-2%-7%) of oxygen (O2 ) concentration...

Impaired microcirculation in acute coronary syndrome (ACS) patients manifests inadequate recovery and adverse clinical outcome. Here, we analyzed correlations between peripheral microcirculation and heart function in ACS patients. Opisthenar microvessel area (OMA) were measured with optical coherence tomography angiography (OCTA), cardiac functional indexes (echocardiograph) were assessed 48-72 hours after therapeutic interventions. Results showed that OMA normalized with heart rate (OMA-HR) were significantly greater in ACS patients with percutaneous intervention (ACS-PCI, n=25, stenosis > 80%) compared to those with pharmacological intervention (ACS-PI, n=23, stenosis < 50%, P=0...

Lymphangiogenesis is the mechanism by which the lymphatic system develops and expands new vessels facilitating fluid drainage and immune cell trafficking. Models to study lymphangiogenesis are necessary for a better understanding of the underlying mechanisms and to identify or test new therapeutic agents that target lymphangiogenesis. Across the lymphatic literature, multiple models have been developed to study lymphangiogenesis in vitro and in vivo. In vitro, lymphangiogenesis can be modeled with varying complexity, from monolayers to hydrogels to explants, with common metrics for characterizing proliferation, migration, and sprouting of lymphatic endothelial cells (LECs) and vessels...

Acute myeloid leukemia (AML) is a heterogeneous malignant condition characterized by massive infiltration of poorly differentiated white blood cells in the blood stream, bone marrow and extramedullary sites. During leukemic development, hepatosplenomegaly is expected to occur because large blood volumes are continuously filtered through these organs. We asked whether infiltration of leukemic blasts initiated a response that could be detected in the interstitial fluid phase of the spleen and liver in a rat model known to mimic human AML in growth characteristics and behavior...

Disease complications can alter vascular network morphology and disrupt tissue functioning. Diabetic retinopathy, for example, is a complication of types 1 and 2 diabetes mellitus that can cause blindness. Microvascular diseases are assessed by visual inspection of retinal images, but this can be challenging when diseases exhibit silent symptoms or patients cannot attend in-person meetings. We examine the performance of machine learning algorithms in detecting microvascular disease when trained on statistical and topological summaries of segmented retinal vascular images...

OBJECTIVE: Coronary microvascular dysfunction is an important component of ischemic heart disease. Here, we assessed the associations between anxiety/depression and coronary microvascular dysfunction using coronary microvascular function indicators. METHODS: The study included 81 patients (26 males and 55 females) with non-obstructive coronary artery disease. The symptoms of anxiety and depression were measured with Self-rating Anxiety Scale and Self-rating Depression Scale...

OBJECTIVE: Laser-based tissue perfusion monitoring techniques have been increasingly used in animal and human research to assess blood flow. However, these techniques use arbitrary units, and knowledge about their comparability is scarce. This study aimed to model the relationship between laser speckle contrast imaging (LSCI) and laser Doppler perfusion imaging (LDPI), for measuring tissue perfusion over a wide range of blood flux values. METHODS: Fifteen healthy volunteers (53% female, median age 29 [IQR 22-40] years) were enrolled in this study...

OBJECTIVE: Post-hepatectomy liver failure (PHLF) is the main limitation of extended liver resection. The molecular mechanism and the role of leukocytes in the development of PHLF remain to be unveiled. We aimed to address the impact of serine proteases (SPs) on the acute phase after liver resection by intravitally analyzing leukocyte recruitment and changes in hemodynamics and microcirculation of the liver. METHODS: C57BL/6 mice undergoing 60% partial hepatectomy were treated with aprotinin (broad-spectrum SP inhibitor), tranexamic acid (plasmin inhibitor), or vehicle...

OBJECTIVE: Endothelial cell (EC) coupling occurs through gap junctions and underlies cerebral blood flow regulation governed by inward-rectifying (KIR ) channels. This study addressed effects of KIR channel activity on EC coupling before and during Alzheimer's disease (AD). METHODS: Intact EC tubes (width: ~90-100 μm; length: ~0.5 mm) were freshly isolated from posterior cerebral arteries of young Pre-AD (1-3 months) and aged AD (13-18 months) male and female 3xTg-AD mice...

OBJECTIVE: The long-term survival of kidney transplant patients has substantially improved. However, there is a higher risk for cardiovascular events after transplantation, partly due to immunosuppression. A diminished number of endothelial progenitor cells (EPCs), which play an important role in angiogenesis and the repair of endothelial damage, is associated with an increased cardiovascular risk. The aim of this study was to evaluate whether kidney transplantation affects EPCs in women...

The lymphatic vascular system is crucial for optimizing body fluid level, regulating immune function, and transporting lipid. Relative to the experimental models to investigate blood vasculature, there are significantly fewer tools to explore lymphatics. Although in vivo studies have contributed to major discoveries in the field, finding and characterizing lymphatic specific markers has opened the door to isolating lymphatic vessels and cells for building ex vivo and in vitro platforms. These preparations have enabled the study and analysis of lymphatic vasculature in various physiological and pathophysiological conditions leading to a better understanding of cellular expressions and signaling...

Dysfunction of the lymphatic system following injury, disease, or cancer treatment can lead to lymphedema, a debilitating condition with no cure. Despite the various physical therapy and surgical options available, most treatments are palliative and fail to address the underlying lymphatic vascular insufficiency driving lymphedema progression. Stem cell therapy provides a promising alternative in the treatment of various chronic diseases with a wide range of therapeutic effects that reduce inflammation, fibrosis, and oxidative stress, while promoting lymphatic vessel (LV) regeneration...

No abstract text is available yet for this article.

OBJECTIVE: Coronary microvascular dysfunction (CMD) is a key pathophysiological feature of hypertrophic cardiomyopathy (HCM), contributing to myocardial ischemia and representing a critical determinant of patients' adverse outcome. The molecular mechanisms underlying the morphological and functional changes of CMD are still unknown. Aim of this study was to obtain insights on the molecular pathways associated with microvessel remodelling in HCM. METHODS: Interventricular septum myectomies from patients with obstructive HCM (n=20) and donors' hearts (CTR, discarded for technical reasons, n=6) were collected...

Lymphatic vessels collect interstitial fluid, immune cells and digested lipids and return these bodily fluids to blood through two pairs of lymphovenous valves (LVVs). Like other cardiovascular valves LVVs prevent the backflow of blood into the lymphatic vessels. In addition to LVVs platelets are necessary to prevent the entry of blood into the lymphatic vessels. Platelet thrombi are observed at LVVs suggesting that LVVs and platelets function in synergy to regulate blood/lymphatic separation. However, whether platelets can regulate blood/lymph separation independently of LVVs is not known...

Microcirculation facilitates the blood-tissue exchange of nutrients and regulates blood perfusion. It is, therefore, essential in maintaining tissue health. Aberrations in microcirculation are potentially indicative of underlying cardiovascular and metabolic pathologies. Thus, quantitative information about it is of great clinical relevance. Photoacoustic imaging (PAI) is a capable technique that relies on the generation of imaging contrast via the absorption of light and can image at micron-scale resolution...

Goreisan is a traditional herbal formulation with diuretic properties tested as a clinical therapeutic to alleviate lymphedema in Japan. The present study aimed to determine how Goreisan and its five different components affect lymphatic pump function. Mesenteric collecting lymphatics were isolated from anesthetized Sprague Dawley rats and mounted on resistance-matched glass micropipettes in a 37 °C physiological salt solution bath for studies. Diameter was continuously measured to obtain the following lymphatic pump parameters: contraction frequency (CF), end diastolic diameter (EDD), and end systolic diameter (ESD), contraction amplitude (AMP), ejection fraction (EF), and fractional pump flow (FPF)...

PURPOSE: NLRP3 inflammasome mediates myocardial ischemia/reperfusion (MI/R) injury and diabetic vascular endothelia dysfunction. However, the role of NLRP3 inflammasome in MI/R injury with diabetes has not been fully described. Irisin plays an important role in anti-inflammation and improves endothelial function in type 2 diabetes. The current study aimed to investigate the effect of irisin on regulating NLRP3 inflammasome activation in diabetic vascular endothelia dysfunction. METHODS: Cardiac microvascular endothelial cells (CMECs) were cultured and subjected to high glucose/high fat (HG/HF) receiving hypoxia/reoxygenation (H/R) with irisin incubation or not...

Over the last century, scientific discoveries have revealed the critical role of the microcirculation in maintaining homeostasis and the etiology of diseases ranging from cancer to COVID-19. These advances have coincided with and even been made possible by the exponential progress in imaging and visualization techniques capable of characterizing the structural and functional diversity of the microcirculation. Consequently, this special issue (SI) showcases a broad selection of tools and methods for elucidating the role of the microcirculation in health and disease...