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Animal Models and Experimental Medicine Aug 2023Pericytes are the main cellular components of tiny arteries and capillaries. Studies have found that pericytes can undergo morphological contraction or relaxation under... (Review)
Review
Pericytes are the main cellular components of tiny arteries and capillaries. Studies have found that pericytes can undergo morphological contraction or relaxation under stimulation by cytokines, thus affecting the contraction and relaxation of microvessels and playing an essential role in regulating vascular microcirculation. Moreover, due to the characteristics of stem cells, pericytes can differentiate into a variety of inflammatory cell phenotypes, which then affect the immune function. Additionally, pericytes can also participate in angiogenesis and wound healing by interacting with endothelial cells in vascular microcirculation disorders. Here we review the origin, biological phenotype and function of pericytes, and discuss the potential mechanisms of pericytes in vascular microcirculation disorders, especially in pulmonary hypertension, so as to provide a sound basis and direction for the prevention and treatment of vascular microcirculation diseases.
Topics: Pericytes; Microcirculation; Endothelial Cells; Capillaries; Biology
PubMed: 37317664
DOI: 10.1002/ame2.12334 -
Frontiers in Endocrinology 2023Diabetic nephropathy (DN) is one of the most common complications of diabetes, and its main manifestations are progressive proteinuria and abnormal renal function, which... (Review)
Review
Diabetic nephropathy (DN) is one of the most common complications of diabetes, and its main manifestations are progressive proteinuria and abnormal renal function, which eventually develops end stage renal disease (ESRD). The pathogenesis of DN is complex and involves many signaling pathways and molecules, including metabolic disorders, genetic factors, oxidative stress, inflammation, and microcirculatory abnormalities strategies. With the development of medical experimental techniques, such as single-cell transcriptome sequencing and single-cell proteomics, the pathological alterations caused by kidney cell interactions have attracted more and more attention. Here, we reviewed the characteristics and related mechanisms of crosstalk among kidney cells podocytes, endothelial cells, mesangial cells, pericytes, and immune cells during the development and progression of DN and highlighted its potential therapeutic effects.
Topics: Humans; Diabetic Nephropathies; Endothelial Cells; Microcirculation; Kidney; Mesangial Cells; Diabetes Mellitus
PubMed: 37538798
DOI: 10.3389/fendo.2023.1173933 -
Journal of Cardiothoracic and Vascular... Oct 2023Cardiogenic shock causes hypoperfusion within the microcirculation, leading to impaired oxygen delivery, cell death, and progression of multiple organ failure.... (Review)
Review
Cardiogenic shock causes hypoperfusion within the microcirculation, leading to impaired oxygen delivery, cell death, and progression of multiple organ failure. Mechanical circulatory support (MCS) is the last line of treatment for cardiac failure. The goal of MCS is to ensure end-organ perfusion by maintaining perfusion pressure and total blood flow. However, machine-blood interactions and the nonobvious translation of global macrohemodynamics into the microcirculation suggest that the use of MCS may not necessarily be associated with improved capillary flow. With the use of hand-held vital microscopes, it is possible to assess the microcirculation at the bedside. The paucity of literature on the use of microcirculatory assessment suggests the need for an in-depth look into microcirculatory assessment within the context of MCS. The purpose of this review is to discuss the possible interactions between MCS and microcirculation, as well as to describe the research conducted in this area. Regarding sublingual microcirculation, 3 types of MCS will be discussed: venoarterial extracorporeal membrane oxygenation, intra-aortic balloon counterpulsation, and microaxial flow pumps (Impella).
Topics: Humans; Microcirculation; Mouth Floor; Shock, Cardiogenic; Heart Failure; Hemodynamics; Heart-Assist Devices; Intra-Aortic Balloon Pumping
PubMed: 37330330
DOI: 10.1053/j.jvca.2023.05.028 -
Frontiers in Pediatrics 2023Cardiovascular instability and reduced oxygenation are regular perioperative critical events associated with anesthesia requiring intervention in neonates and young... (Review)
Review
Cardiovascular instability and reduced oxygenation are regular perioperative critical events associated with anesthesia requiring intervention in neonates and young infants. This review article addresses the current modalities of assessing this population's adequate end-organ perfusion in the perioperative period. Assuring adequate tissue oxygenation in critically ill infants is based on parameters that measure acceptable macrocirculatory hemodynamic parameters such as vital signs (mean arterial blood pressure, heart rate, urinary output) and chemical parameters (lactic acidosis, mixed venous oxygen saturation, base deficit). Microcirculation assessment represents a promising candidate for assessing and improving hemodynamic management strategies in perioperative and critically ill populations. Evaluation of the functional state of the microcirculation can parallel improvement in tissue perfusion, a term coined as "hemodynamic coherence". Less information is available to assess microcirculatory disturbances related to higher mortality risk in critically ill adults and pediatric patients with septic shock. Techniques for measuring microcirculation have substantially improved in the past decade and have evolved from methods that are limited in scope, such as velocity-based laser Doppler and near-infrared spectroscopy, to handheld vital microscopy (HVM), also referred to as videomicroscopy. Available technologies to assess microcirculation include sublingual incident dark field (IDF) and sublingual sidestream dark field (SDF) devices. This chapter addresses (1) the physiological basis of microcirculation and its relevance to the neonatal and pediatric populations, (2) the pathophysiology associated with altered microcirculation and endothelium, and (3) the current literature reviewing modalities to detect and quantify the presence of microcirculatory alterations.
PubMed: 37842022
DOI: 10.3389/fped.2023.1123405 -
Stroke Oct 2023The only established pharmacological treatment option improving outcomes for patients suffering from subarachnoid hemorrhage (SAH) is the L-type-calcium channel...
BACKGROUND
The only established pharmacological treatment option improving outcomes for patients suffering from subarachnoid hemorrhage (SAH) is the L-type-calcium channel inhibitor nimodipine. However, the exact mechanisms of action of nimodipine conferring neuroprotection after SAH have yet to be determined. More recently, spasms of the cerebral microcirculation were suggested to play an important role in reduced cerebral perfusion after SAH and, ultimately, outcome. It is unclear whether nimodipine may influence microvasospasms and, thus, microcirculatory dysfunction. The aim of the current study was, therefore, to assess the effect of nimodipine on microvasospasms after experimental SAH.
METHODS
Male C57Bl/6 N mice (n=3-5/group) were subjected to SAH using the middle cerebral artery perforation model. Six hours after SAH induction, a cranial window was prepared, and the diameter of cortical microvessels was assessed in vivo by 2-photon-microscopy before, during, and after nimodipine application.
RESULTS
Nimodipine significantly reduced the number of posthemorrhagic microvasospasms. The diameters of nonspastic vessels were not affected.
CONCLUSIONS
Our results show that nimodipine reduces the formation of microvasospasms, thus, shedding new light on the mode of action of a drug routinely used for the treatment of SAH for >3 decades. Furthermore, L-type Ca2+ channels may be involved in the pathophysiology of microvasospasm formation.
Topics: Humans; Animals; Mice; Male; Nimodipine; Subarachnoid Hemorrhage; Microcirculation; Mice, Inbred C57BL; Microvessels
PubMed: 37675614
DOI: 10.1161/STROKEAHA.123.043976 -
Medicinski Glasnik : Official... Aug 2023Aim To investigate the effect of direct epineural electrical stimulation of the nerve on the nature of reparative processes in the bone stump. Methods Three series of...
Aim To investigate the effect of direct epineural electrical stimulation of the nerve on the nature of reparative processes in the bone stump. Methods Three series of experiments were carried out with amputation of the thigh in the middle third and muscle plasty. In the 1st and 2nd experimental series a perineural catheter was brought to the stump of the sciatic nerve, through which mechanical irritation of the nerve was performed for 20 days daily for 20 minutes. In the 2nd series, an electrode was added to the nerve and epineural electrical stimulation was performed daily for 20 days. Animals of the 3rd series served as control. The observation periods were 1, 3, 6 months. Histological research method with filling vessels with ink-gelatin mixture was applied. Results In the 1st series, there was a sharp distortion of the reparative process, which consisted of a violation of microcirculation, changes in shape, resorption of the cortical diaphyseal plate, fractures, deformations. In most experiments of the 2nd series, organotypic stumps were formed with normalization of microcirculation. In the 3rd series, results of the formation of the stump were better than in the 1st, but worse than in the 2nd series. Conclusions Painful nerve irritation after amputation leads to a significant disturbance of microcirculation and reparative regeneration at the end of the bone stump with the development of pathological restructuring of bone tissue. Electrostimulation of the nerve improves microcirculation and reparative regeneration of the bone tissue.
PubMed: 37421178
DOI: 10.17392/1602-23 -
Microvascular Research May 2024Coronary microvascular dysfunction (CMD) is a key mechanism underlying ischemic heart disease (IHD), yet its diagnosis and treatment remain challenging. This article... (Review)
Review
Coronary microvascular dysfunction (CMD) is a key mechanism underlying ischemic heart disease (IHD), yet its diagnosis and treatment remain challenging. This article presents a comprehensive overview of CMD research, covering its pathogenesis, diagnostic criteria, assessment techniques, risk factors, and therapeutic strategies. Additionally, it highlights the prospects for future CMD research. The article aims at advocating early and effective intervention for CMD and improving the prognosis of IHD.
Topics: Humans; Coronary Circulation; Myocardial Ischemia; Prognosis; Coronary Artery Disease; Microcirculation
PubMed: 38211894
DOI: 10.1016/j.mvr.2024.104652 -
Biomedicine & Pharmacotherapy =... Aug 2023Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the... (Review)
Review
Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the pathophysiological mechanism of CMD is still limited at present, which greatly restricts its clinical diagnosis and treatment. Studies have shown that CMD is closely related to a variety of cardiovascular diseases, can aggravate the occurrence and development of cardiovascular diseases, and is closely related to a poor prognosis in patients with cardiovascular diseases. Improving coronary microvascular remodelling and increasing myocardial perfusion might be promising strategies for the treatment of cardiovascular diseases. In this paper, the pathogenesis and functional assessment of CMD are reviewed first, along with the relationship of CMD with cardiovascular diseases. Then, the latest strategies for the treatment of CMD and cardiovascular diseases are summarized. Finally, urgent scientific problems in CMD and cardiovascular diseases are highlighted and future research directions are proposed to provide prospective insights for the prevention and treatment of CMD and cardiovascular diseases in the future.
Topics: Humans; Cardiovascular Diseases; Coronary Circulation; Myocardial Ischemia; Microcirculation
PubMed: 37321056
DOI: 10.1016/j.biopha.2023.115011 -
Acta Physiologica (Oxford, England) Nov 2023This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow.... (Review)
Review
This review outlines the features of tandem regulation of glomerular microcirculation by autoregulatory mechanisms and intraglomerular redistribution of blood flow. Multiple points of cooperation exist between autoregulatory and distributional mechanisms. Mutual interactions between myogenic and tubuloglomerular feedback (TGF) mechanisms regulating the inflow are briefly discussed. In addition to this, TGF operation involving purinergic, autocoid, and NO signaling affects, however, not only afferent arteriolar tone, but mesangial cell tone as well. The latter reversibly reconfigures the distribution of blood flow between the shorter and longer pathways in the glomerular tuft. I advance a hypothesis that blood flow in these pathways spontaneously alternates, and mesangial cell tonicity serves as a rheostatic shift between them. Furthermore, humoral messengers from macula densa cells, themselves dependent on myogenic mechanisms, fine-tune the secretion of renin and, subsequently, the local, intrarenal generation of angiotensin II, which, in turn, provides additional vasomotor signaling to glomerular capillaries through changing the tone of mesangial cells. This complex regulatory network may partially explain the phenomenon of renal functional reserve, as well as suggest implications for changes in renal function during pregnancy, early diabetes mellitus, and acute kidney injury.
Topics: Female; Humans; Pre-Eclampsia; Microcirculation; Kidney; Kidney Glomerulus; Diabetes Mellitus; Kidney Diseases
PubMed: 37688412
DOI: 10.1111/apha.14048 -
Clinical & Experimental Optometry Sep 2023The conjunctival microcirculation is an accessible complex network of micro vessels whose quantitative assessment can reveal microvascular haemodynamic properties.... (Review)
Review
The conjunctival microcirculation is an accessible complex network of micro vessels whose quantitative assessment can reveal microvascular haemodynamic properties. Currently, algorithms for the measurement of conjunctival haemodynamics use either manual or semi-automated systems, which may provide insight into overall conjunctival health, as well as in ocular and systemic disease. These algorithms include functional slit-lamp biomicroscopy, laser doppler flowmetry, optical coherence tomography angiography, orthogonal polarized spectral imaging, computer-assisted intravitral microscopy, diffuse reflectance spectroscopy and corneal confocal microscopy. Furthermore, several studies have demonstrated a relationship between conjunctival microcirculatory haemodynamics and many diseases such as dry eye disease, Alzheimer's disease, diabetes, hypertension, sepsis, coronary microvascular disease, and sickle cell anaemia. This review aims to describe conjunctival microcirculation, its characteristics, and techniques for its measurement, as well as the association between conjunctival microcirculation and microvascular abnormalities in disease states.
Topics: Humans; Blood Flow Velocity; Microcirculation; Conjunctiva; Hemodynamics; Slit Lamp Microscopy
PubMed: 36641840
DOI: 10.1080/08164622.2022.2151872