Capillary rarefaction

BACKGROUND: Heart diseases are among the leading causes of death worldwide, many of which lead to pathological cardiomyocyte hypertrophy and capillary rarefaction in both patients and animal models, the quantification of which is both technically challenging and highly time-consuming. Here we developed a semiautomated pipeline for quantification of the size of cardiomyocytes and capillary density in cardiac histology, termed HeartJ, by generating macros in ImageJ, a broadly used, open-source, Java-based software...

Salt sensitivity concerns blood pressure alterations after a change in salt intake (sodium chloride). The heart is a pump, and vessels are tubes; sodium can affect both. A high salt intake increases cardiac output, promotes vascular dysfunction and capillary rarefaction, and chronically leads to increased systemic vascular resistance. More recent findings suggest that sodium also acts as an important second messenger regulating energy metabolism and cellular functions. Besides endothelial cells and fibroblasts, sodium also affects innate and adaptive immunometabolism, immune cell function, and influences certain microbes and microbiota-derived metabolites...

We employed an early training exercise program, immediately after recovery from surgery, and before severe cardiac hypertrophy, to study the underlying mechanism involved with the amelioration of cardiac dysfunction in aortic stenosis (AS) rats. As ET induces angiogenesis and oxygen support, we aimed to verify the effect of exercise on myocardial lipid metabolism disturbance. Wistar rats were divided into Sham, trained Sham (ShamT), AS and trained AS (AST). The exercise consisted of 5-week sessions of treadmill running for 16 weeks...

Whole brain irradiation (WBI), a commonly employed therapy for multiple brain metastases and as a prophylactic measure after cerebral metastasis resection, is associated with a progressive decline in neurocognitive function, significantly impacting the quality of life for approximately half of the surviving patients. Recent preclinical investigations have shed light on the multifaceted cerebrovascular injury mechanisms underlying this side effect of WBI. In this study, we aimed to test the hypothesis that WBI induces endothelial senescence, contributing to chronic disruption of the blood-brain barrier (BBB) and microvascular rarefaction...

Cardiovascular regulation of tissue oxygenation is generally viewed as an anti-drop process that prevents tissue oxygen concentration from falling below some minimum. I propose that cardiovascular regulation is predominately an anti-rise process designed to down-regulate oxygen delivery. This maintains an evolutionarily-conserved, reduced intracellular environment to prevent oxidation of redox-sensitive regulatory protein thiols. A number of points support this hypothesis. 1) Oxygen is the only nutrient with a positive, four-fold diffusion gradient from the environment to systemic tissues, minimizing the likelyhood that oxygen delivery is limited...

Studies have highlighted the significant involvement of kidney pericytes in renal fibrosis. Kidney pericytes, classified as interstitial mesenchymal cells, are extensively branched, collagen-producing cells that closely interact with endothelial cells. This article aims to provide an overview of the recent advancements in understanding the physiological functions of pericytes and their roles in kidney diseases. In a healthy kidney, pericytes have essential physiological function in angiogenesis, erythropoietin (EPO) production, and the regulation of renal blood flow...

Arterial hypertension is a common condition worldwide and an important risk factor for cardio- and cerebrovascular events, renal diseases, as well as microvascular eye diseases. Established hypertension leads to the chronic vasoconstriction of small arteries as well as to a decreased lumen diameter and the thickening of the arterial media or wall with a consequent increased media-to-lumen ratio (MLR) or wall-to-lumen ratio (WLR). This process, defined as vascular remodeling, was firstly demonstrated in small resistance arteries isolated from subcutaneous biopsies and measured by micromyography, and this is still considered the gold-standard method for the assessment of structural alterations in small resistance arteries; however, microvascular remodeling seems to represent a generalized phenomenon...

OBJECTIVES: This study aimed to evaluate the effects of the antidiabetics liraglutide, a GLP-1 analog, and empagliflozin, an SGLT-2 inhibitor, on the brain microcirculation of diabetic rats. METHODS: Type 2 diabetes mellitus (DM) was experimentally induced in male Wistar rats by combining a high-fat diet and a low dose of streptozotocin (35 mg/kg). Liraglutide (100 μg/kg s.c.) and empagliflozin (10 mg/kg, oral) were administered for 5 weeks...

The contribution of the right ventricle (RV) to cardiac output is negligible in normal resting conditions when pressures in the pulmonary circulation are low. However, the RV becomes relevant in healthy subjects during exercise, and definitely so in patients with increased pulmonary artery pressures both at rest and during exercise. The adaptation of RV function to loading rests basically on an increased contractility. This is assessed by RV end-systolic elastance (Ees) to match afterload assessed by arterial elastance (Ea)...

Because of structural and cellular differences (ie, degrees of matrix abundance and cross-linking, mural cell density, and adventitia), large and medium-sized vessels, in comparison to capillaries, react in a unique manner to stimuli that induce vascular disease. A stereotypical vascular injury response is ECM (extracellular matrix) remodeling that occurs particularly in larger vessels in response to injurious stimuli, such as elevated angiotensin II, hyperlipidemia, hyperglycemia, genetic deficiencies, inflammatory cell infiltration, or exposure to proinflammatory mediators...

PURPOSE OF REVIEW: To review current literature examining the presence of subclinical micro- and macrovascular alterations in normotensive individuals and their clinical significance in terms of hypertension prediction. Emphasis is placed on alterations that can be detected in peripheral vascular beds using non-invasive, easily applicable methodology, as these are in general easier to capture and evaluate in clinical practice compared to more complex invasive or functional tests. RECENT FINDINGS: Arterial stiffness, increased carotid intima-media thickness, and altered retinal microvascular diameters predict the progression from the normotensive to the hypertensive state...

A relevant percentage of IgAN patients experience a progressive decline in kidney function. According to the KDIGO guidelines, proteinuria and eGFR are the only validated prognostic markers. The role of interstitial macrophages in kidney biopsies of IgAN patients and the outcome of patients treated with renin-angiotensin system inhibitors (RASBs) alone or combined with glucocorticoids were evaluated. Clinical and laboratory records (age, gender, hypertension, hematuria, proteinuria, eGFR, serum creatinine, and therapy), MEST-C parameters of the Oxford classification, C4d deposition, peritubular capillaries, and glomerular and interstitial macrophages in 47 IgAN patients undergoing kidney biopsy consecutively between 2003 and 2016 were examined...

Patients with chronic kidney disease (CKD) have an increased risk for cardiovascular morbidity and mortality. Capillary rarefaction may be both one of the causes as well as a consequence of CKD and cardiovascular disease. We reviewed the published literature on human biopsy studies and conclude that renal capillary rarefaction occurs independently of the cause of renal function decline. Moreover, glomerular hypertrophy may be an early sign of generalized endothelial dysfunction, while peritubular capillary loss occurs in advanced renal disease...

Angiogenesis is an important exercise-induced response to improve blood flow and decrease vascular resistance in spontaneously hypertensive rats (SHR), but some antihypertensive drugs attenuate this effect. This study compared the effects of captopril and perindopril on exercise-induced cardiac and skeletal muscle angiogenesis. Forty-eight Wistar rats and 48 SHR underwent 60 days of aerobic training or were kept sedentary. During the last 45 days, rats were treated with captopril, perindopril or water (Control)...

Local overexposure to ionizing radiation leads to chronic inflammation, vascular damage and cachexia. Here we investigate the kinetics of inflammatory cells from day (D)1 to D180 after mouse hindlimb irradiation and analyze the role of monocyte (Mo) subsets in tissue revascularization. At D1, we find that Mo and T cells are mobilized from spleen and bone marrow to the blood. New vessel formation during early phase, as demonstrated by ~1.4- and 2-fold increased angiographic score and capillary density, respectively, correlates with an increase of circulating T cells, and Mohi and type 1-like macrophages in irradiated muscle...

Perivascular spaces (PVS) and their enlargement (EPVS) have been gaining interest as EPVS can be visualized non-invasively by magnetic resonance imaging (MRI) when viewing T-2-weighted images. EPVS are most commonly observed in the regions of the basal ganglia and the centrum semiovale; however, they have also been identified in the frontal cortex and hippocampal regions. EPVS are known to be increased in aging and hypertension, and are considered to be a biomarker of cerebral small vessel disease (SVD). Interest in EPVS has been significantly increased because these PVS are now considered to be an essential conduit necessary for the glymphatic pathway to provide the necessary efflux of metabolic waste...

Lungs are constantly exposed to environmental perturbations and have therefore remarkable capacity to regenerate in response to injury. Sustained lung injuries, aging and increased genomic instability, however, make lungs particularly susceptible to dysrepair and fibrosis. Pulmonary fibrosis constitutes a major cause of morbidity and is often relentlessly progressive, leading to death from respiratory failure. The pulmonary vasculature, which is critical for gas exchanges and plays a key role during lung development, repair, and regeneration, becomes aberrantly remodeled in patients with progressive pulmonary fibrosis...

Damage to peritubular capillaries is a key process that contributes to acute kidney injury (AKI) progression. Vascular endothelial growth factor A (VEGFA) plays a critical role in maintaining the renal microvasculature. However, the physiological role of VEGFA in various AKI durations remains unclear. A severe unilateral ischemia‒reperfusion injury model was established to provide an overview of VEGFA expression and the peritubular microvascular density from acute to chronic injury in mouse kidneys. Therapeutic strategies involving early VEGFA supplementation protecting against acute injury and late anti-VEGFA treatment for fibrosis alleviation were analyzed...

BACKGROUND: Autosomal Recessive Bestrophinopathy (ARB) is an inherited retinal disease caused by biallelic mutations in the BEST1 gene. Herein, we report the multimodal imaging findings of ARB presenting with cystoid maculopathy and investigate the short-term response to combined systemic and topical carbonic anhydrase inhibitors (CAIs). MATERIAL AND METHODS: An observational, prospective, case series on two siblings affected by ARB is presented. Patients underwent genetic testing and optical coherence tomography (OCT), blue-light fundus autofluorescence (BL-FAF), near-infrared fundus autofluorescence (NIR-FAF), fluorescein angiography (FA), MultiColor imaging, and OCT angiography (OCTA)...

AIMS: To investigate the correlation between the retinal microvasculature using optical coherence tomography angiography (OCTA) and systemic factors in type 2 diabetes mellitus (T2DM) patients. METHODS: This cross-sectional study obtained OCTA data from patients with T2DM administered at hospital and referred to ophthalmic services. Patient data about demographics, comorbid conditions, and blood biomarkers were extracted from electronic medical records. Data from OCTA scans obtained by CIRRUS HD-OCT Model 5,000 were obtained...