Abstract:
:We have videorecorded spontaneous cyclic contractions of capillary walls which often stopped the flow of blood cells, in spleens of rat and mouse. An inverted microscope and oblique lighting were key elements in obtaining images in which the boundaries of cells composing vessel walls were clearly distinguishable. Using slow motion replay, we measured the widths of endothelial cells (C), pericytes (P, when present) and capillary lumens (L; at the site of constriction; U; 15-20 micron upstream), throughout 11-12 min sequences containing many contraction/relaxation cycles. In roughly 50% of contractions L decreased to 0-1 micron, such luminal "closures" occurring within 2-12 sec and lasting for less than 1 sec to greater than 1 min. Intervals between contractions ranged from 12 sec to 3 min (average 1 min). Documentation of one such cycle by sequential photographs from the video monitor is presented, showing dramatic bulging of an endothelial cell into the lumen. Comparison of records of L and C versus time showed that almost invariably when L decreased C increased, and vice versa; highly significant correlations existed between C and L in every case (P less than 0.0005). Multiple linear regression analysis showed that changes in C were responsible for 18-77% of the total variance in L, whereas P contributed only 0-4%; changes in U, covariance between C, P, and U, and unexplained variance were responsible for 0-20, 11-30, and 11-53%, respectively, of the total variance in L. We conclude that these spontaneous capillary contractions were primarily due to endothelial contractility.
journal_name
Microvasc Resjournal_title
Microvascular researchauthors
Ragan DM,Schmidt EE,MacDonald IC,Groom ACdoi
10.1016/0026-2862(88)90035-0subject
Has Abstractpub_date
1988-07-01 00:00:00pages
13-30issue
1eissn
0026-2862issn
1095-9319pii
0026-2862(88)90035-0journal_volume
36pub_type
杂志文章abstract::The purpose of this study was to elucidate the mechanism by which bradykinin (BK) enhances prostacyclin (PGI(2)) production in human umbilical vein endothelial cells (HUVEC). BK-induced enhancement of PGI(2) synthesis was observed in a dose- and time-dependent manner, and it also increased [Ca(2+)](i) followed by enha...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.1999.2163
更新日期:1999-09-01 00:00:00
abstract::Angiotensin II is considered to have angiogenic properties. Nevertheless, several authors reported an increase in coronary capillary density after treatment with ACE inhibitors. The aim of the present study was to evaluate the effect of treatment with low doses of ACE inhibitor perindopril, low doses of the diuretic i...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.1999.2224
更新日期:2000-03-01 00:00:00
abstract::We tested the hypothesis that p42/44MAPK and p38MAPK (mitogen-activated protein kinases; MAPK) signaling pathways regulate endothelial cell permeability to macromolecules. Passage 2-4 human umbilical vein endothelial cells (HUVEC) were grown to confluence on fibronectin-coated Snapwell membranes. The flux of fluoresce...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.2001.2381
更新日期:2002-03-01 00:00:00
abstract::Pericytes are perivascular support cells, the origin of which in tumor tissue is not clear. Recently, we identified a Tie1(+) precursor cell that differentiates into vascular smooth muscle, in a Notch-dependent manner. To understand the involvement of Notch in the ontogeny of tumor pericytes we used a novel flow immun...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2015.05.004
更新日期:2015-09-01 00:00:00
abstract:OBJECTIVE:Vascular endothelial cells (ECs) are constantly exposed to blood flow associated forces such as cyclic strain due to blood pressure, which affects ECs survival and angiogenesis by producing ROS via NAD(P)H oxidase. NAD(P)H oxidase subunit p22phox is reported to be related to the development of atherosclerosis...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2008.08.001
更新日期:2009-03-01 00:00:00
abstract::The maturational changes in tissue water spaces and in the fractional exclusion of albumin from the interstitial gel were studied in the developing rabbit using multiple radioactive tracers. Total tissue water and extracellular water decrease with age in all organs studied. Intracellular water decreases in the heart a...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(86)90021-x
更新日期:1986-05-01 00:00:00
abstract:AIMS:The purpose of the present study was to investigate the possible role of TIPE2 on acute lung injury (ALI) induced by myocardial ischemia/reperfusion (MIR) in diabetic rats. METHODS:Sprague-Dawley (SD) rats were randomly separated into four groups: control+sham (C + sham); control+MIR (C + MIR); diabetes+sham (D +...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2020.104009
更新日期:2020-07-01 00:00:00
abstract::We examined the impact of lymph flow obstruction in large post-nodal lymphatic vessels in sheep. A silk ligature was placed 2 cm downstream from the prescapular or popliteal lymph node and tightened to interrupt flow. At 6, 12 and 16 weeks after lymph flow blockage, a network of small interconnecting lymphatics (appro...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2006.11.003
更新日期:2007-05-01 00:00:00
abstract:OBJECTIVES:The advanced glycation end products (AGEs)-receptor for AGE (RAGE) axis activity are implicated in diabetic vascular complications. We measured serum AGE, sRAGE and pentosidine levels in Tunisian patients with diabetic retinopathy (DR) and examined whether these biomarkers are related to the severity of DR. ...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2012.07.006
更新日期:2012-11-01 00:00:00
abstract::Excessive generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS), by activated neutrophils and endothelial cells, has been implicated in the pathophysiology of endothelial barrier dysfunction. Disruption of the integrity of this barrier markedly increases permeability to fluids, solutes and in...
journal_title:Microvascular research
pub_type: 杂志文章,评审
doi:10.1016/j.mvr.2008.10.005
更新日期:2009-01-01 00:00:00
abstract:OBJECTIVE:High aerobic fitness may prevent age-related decrements in cutaneous vasodilation while type 2 diabetes may exacerbate this decline. The mechanisms underlying these responses remain unclear, but may be due to an excess of reactive oxygen species. We hypothesized that superoxide scavenging or NADPH oxidase inh...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2019.103886
更新日期:2019-09-01 00:00:00
abstract::The first description of endothelial progenitor cells (EPC) in 1997 led rapidly to substantial changes in our understanding of angiogenesis, and within 5 years to the first clinical studies in humans using bone marrow derived EPC to enhance coronary neovascularisation and cardiac function after myocardial ischemia. Ho...
journal_title:Microvascular research
pub_type: 杂志文章,评审
doi:10.1016/j.mvr.2009.12.004
更新日期:2010-05-01 00:00:00
abstract::To investigate the effect of vascular endothelial growth factor (VEGF) on solute permeability of mammalian microvessels, we measured the apparent permeability (P) of various-sized solutes on the postcapillary venules of rat mesentery in vivo. Exposure to 1 nM VEGF transiently increased P from a mean of 1.4 (+/-0.11 SE...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2004.03.004
更新日期:2004-07-01 00:00:00
abstract::Leukocyte margination in the vessels of the microcirculation has been attributed to a flow-dependent interaction with red cells. To determine the extent of this effect, experiments with human blood were done in 100- to 180-micron tubes to detect changes in cell distribution as a function of hematocrit and flow rate. U...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(84)90054-2
更新日期:1984-03-01 00:00:00
abstract::Endothelial dysfunction is common in patients with chronic kidney disease (CKD) and contributes significantly to the high long-term cardiovascular morbidity and mortality. The short-term cardiovascular effects of recombinant human growth hormone (rhGH) in CKD patients (stages III-V) and healthy controls (n=15 each) we...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2009.05.006
更新日期:2009-09-01 00:00:00
abstract:OBJECTIVE:Leukocytes play a key role in the early response to tissue injury/infection resulting from physical, chemical or biological stimuli. This process involves the initiation of the leukocyte adhesion cascade mediated by a series of interactions between receptors and ligands on the endothelium and the leukocytes. ...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2013.03.007
更新日期:2013-09-01 00:00:00
abstract::The purpose of this study was to determine if there are intrinsic differences in resting tone, vascular reactivity, myogenic responses, and neurogenic vasoconstriction between the large and small feeder arteries and first order arterioles (1A) of the rat cremaster muscle. The pudic-epigastric artery (PEA), external sp...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1006/mvre.2000.2259
更新日期:2000-09-01 00:00:00
abstract::The role of VEGF during development and in pathology is well known, but its function in normal adult tissues is poorly understood. Adverse effects associated with the use of anti-angiogenic therapies targeting VEGF in human pathologies have begun to reveal potential functions of VEGF in quiescent vasculature. Further ...
journal_title:Microvascular research
pub_type: 杂志文章,评审
doi:10.1016/j.mvr.2007.03.004
更新日期:2007-09-01 00:00:00
abstract:PURPOSE:The conjunctival microcirculation is a readily-accessible vascular bed for quantitative haemodynamic assessment and has been studied previously using a digital charge-coupled device (CCD). Smartphone video imaging of the conjunctiva, and haemodynamic parameter quantification, represents a novel approach. We rep...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2019.103907
更新日期:2019-11-01 00:00:00
abstract::Purine nucleosides and nucleobases play key roles in the physiological response to vascular ischemia/reperfusion events. The intra- and extracellular concentrations of these compounds are controlled, in part, by equilibrative nucleoside transporter subtype 1 (ENT1; SLC29A1) and by equilibrative nucleobase transporter ...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2014.06.008
更新日期:2014-09-01 00:00:00
abstract::The angiopoietin/Tie2 system is a predominant regulator of vascular development. This vascular development appears to be controlled and completed by the coordinated actions of two vascular cells, endothelial cells and their surrounding supporting cells, smooth muscle cells, or pericytes. The role of the angiopoietin/T...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/s0026-2862(02)00035-3
更新日期:2003-03-01 00:00:00
abstract::Pulmonary arterial hypertension is a common complication of congenital heart defects with left-to-right shunts. Current preclinical models do not reproduce clinical characteristics of shunt-related pulmonary hypertension. Aorto-caval shunt was firstly described as a model of right ventricle volume overload. The pathop...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2014.05.005
更新日期:2014-07-01 00:00:00
abstract::Rho-associated kinases are involved in regulation of actin-myosin contractility and the organization of the actin cytoskeleton in both endothelial and smooth muscle cells. By influencing the contraction of the intraendothelial filaments, Rho kinases may affect the size of the interendothelial gaps and thereby influenc...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/s0026-2862(03)00041-4
更新日期:2003-09-01 00:00:00
abstract::Laser Doppler flowmetry (LDF) of forearm skin blood flow, combined with iontophoretically-administered acetylcholine and sodium nitroprusside and wavelet spectral analysis, was used for noninvasive evaluation of endothelial function in 17 patients newly diagnosed with New York Heart Association class II-III congestive...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2008.07.006
更新日期:2008-11-01 00:00:00
abstract::Innate immunity is characterized by the coordinated activity of multiple leukocytes mobilizing at or near the site of tissue injury. Slow rolling and/or adherent leukocytes have been shown to hydrodynamically recruit free-stream leukocytes to a model of inflamed tissue. In this paper, we numerically investigate the hy...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2017.09.002
更新日期:2018-01-01 00:00:00
abstract::An intravital microscopic method for quantitative measurement of interstitial concentrations of fluorescent tracers has been applied to the investigation of microvascular permeability in the hamster cheek pouch. Some nanoliters of FITC-dextran mean mol wt (Mw) 20,000, 3000, or sodium fluorescein (Mw 376) were injected...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(86)90009-9
更新日期:1986-01-01 00:00:00
abstract:BACKGROUND:Ischemia-reperfusion (IR) injury impairs microcirculatory function by reducing nitric oxide (NO) bioavailability and increasing sympathetic tone. This study non-invasively examined the effects of acute upper limb IR injury on local thermal hyperemia (LTH) in glabrous and non-glabrous finger skin. MATERIALS ...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/j.mvr.2018.02.003
更新日期:2018-07-01 00:00:00
abstract::The effect of isoprenaline infusion (1 gamma/min) on blood flow in the extremities was studied in 15 Raynaud's disease (RD) patients and 9 healthy controls. A highly significant (P less than 0.0005) decrease in blood flow was seen in the RD subjects. It is suggested that an increased presynaptic beta receptor response...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(84)90045-1
更新日期:1984-01-01 00:00:00
abstract::Leptin, a circulating hormone secreted mainly from adipose tissues, is involved in the control of body weight. Recently, leptin was found to be an angiogenic factor, and its vitreous levels are associated with angiogenic eye diseases such as proliferative diabetic retinopathy. However, the molecular mechanism for lept...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/s0026-2862(03)00005-0
更新日期:2003-05-01 00:00:00
abstract::Microvascular blood flow is commonly calculated from a "centerline" velocity derived from the dual-slit method. This is done by relating the computed centerline velocity to an average velocity through an empirically derived conversion factor. To determine the physical basis of the conversion factor, we utilized a Four...
journal_title:Microvascular research
pub_type: 杂志文章
doi:10.1016/0026-2862(89)90046-0
更新日期:1989-05-01 00:00:00