Search results for "Helium"
showing 10 items of 1689 documents
Roflumilast inhibits leukocyte-endothelial cell interactions, expression of adhesion molecules and microvascular permeability
2007
Background and purpose: The present study addressed the effects of the investigational PDE4 inhibitor roflumilast on leukocyte-endothelial cell interactions and endothelial permeability in vivo and in vitro. Experimental approach: In vivo, intravital video-microscopy was used to determine effects of roflumilast p.o. on leukocyte-endothelial cell interactions and microvascular permeability in rat mesenteric venules. In vitro, the effects of roflumilast N-oxide, the active metabolite of roflumilast in humans, and other PDE4 inhibitors on neutrophil adhesion to tumour necrosis factor α (TNFα)-activated human umbilical vein endothelial cells (HUVEC), E-selectin expression and thrombin-induced e…
Neurogenic contraction and relaxation of human penile deep dorsal vein
1998
The aim of the present study was to characterize neurogenic and pharmacological responses of human penile deep dorsal vein and to determine whether the responses are mediated by nitric oxide from neural or endothelial origin. Ring segments of human penile deep dorsal vein were obtained from 22 multiorgan donors during procurement of organs for transplantation. The rings were suspended in organ bath chambers for isometric recording of tension. We then studied the contractile and relaxant responses to electrical field stimulation and to vasoactive agents. Electrical field stimulation (0.5–2 Hz) and noradrenaline (3×10−10–3×10−5M) caused frequency- and concentration-dependent contractions that…
The Non-neuronal Cholinergic System
2001
An increasing body of knowledge indicates that the cholinergic system is not confined to the nervous system, but is practically ubiquitous. The present paper will address the question of the non-neuronal cholinergic system in vascular endothelial cells (EC). In tissue sections of human skin, immunohistochemical studies using confocal laser scanning microscopy showed ChAT (choline acetyltransferase) activity in the EC of dermal blood vessels. Positive ChAT immunoreactivity was also demonstrated in monolayer cultures of human umbilical vein EC (HUVEC) and a human angiosarcoma EC line (HAEND). That the synthesizing enzyme is not only present in EC, but also active was shown by measuring ChAT a…
Airway epithelium: more than just a barrier!
1999
Abstract Airway epithelium: source of non-neuronal acetylcholine and modulator of neurotransmission
Reduction of tumor necrosis factor-alpha (TNF-α) related nuclear factor-kappaB (NF-κB) translocation but not inhibitor kappa-B (Iκ-B)-degradation by …
2002
Degradation of inhibitor kappa-B (Ikappa-B) followed by translocation of nuclear factor-kappaB (NF-kappaB) into the nucleus and activation of gene expression is essential in tumor necrosis factor-alpha (TNF-alpha)-signaling. In order to analyze the role of Rho proteins in TNF-alpha-induced NF-kappaB-activation in human umbilical cord vein endothelial cells (HUVEC) we used Clostridium difficile toxin B-10463 (TcdB-10463) which inactivates RhoA/Rac1/Cdc42 by glucosylation and Clostridium botulinum C3-toxin which inhibits RhoA/B/C by ADP-ribosylation. Exposure of HUVEC to 10 ng/mL TcdB-10463 or 2.5 microg/mL C3-toxin inhibited TNF-alpha (100 ng/mL)-induced expression of a NF-kappaB-dependent r…
Angiotensin II is involved in nitric oxide synthase and cyclo-oxygenase inhibition-induced leukocyte-endothelialcell interactionsin vivo
2001
Chronic inhibition of nitric oxide synthase (NOS) provokes a hypertensive state which has been shown to be angiotensin II (Ang-II) dependent. In addition to raising blood pressure, NOS inhibition also causes leukocyte adhesion. The present study was designed to define the role of Ang-II in hypertension and in the leukocyte-endothelial cell interactions induced by acute NOS or cyclo-oxygenase (COX) inhibition using intravital microscopy within the rat mesenteric microcirculation. While pretreatment with an Ang-II AT1 receptor antagonist (losartan) reversed the prompt increase in mean arterial blood pressure (MABP) caused by indomethacin, it had no effect on the increase evoked by systemic L-…
The α1B-adrenoceptor subtype mediates adrenergic vasoconstriction in mouse retinal arterioles with damaged endothelium
2014
Background and Purpose The α1-adrenoceptor family plays a critical role in regulating ocular perfusion by mediating responses to catecholamines. The purpose of the present study was to determine the contribution of individual α1-adrenoceptor subtypes to adrenergic vasoconstriction of retinal arterioles using gene-targeted mice deficient in one of the three adrenoceptor subtypes (α1A-AR−/−, α1B-AR−/− and α1D-AR−/− respectively). Experimental Approach Using real-time PCR, mRNA expression for individual α1-adrenoceptor subtypes was determined in murine retinal arterioles. To assess the functional relevance of the three α1-adrenoceptor subtypes for mediating vascular responses, retinal vascular…
Increased endothelin-1 vasoconstriction in mesenteric resistance arteries after superior mesenteric ischaemia-reperfusion
2012
BACKGROUND AND PURPOSE Endothelin-1 (ET-1) plays an important role in the maintenance of vascular tone. We aimed to evaluate the influence of superior mesenteric artery (SMA) ischaemia-reperfusion (I/R) on mesenteric resistance artery vasomotor function and the mechanism involved in the changes in vascular responses to ET-1. EXPERIMENTAL APPROACH SMA from male Sprague-Dawley rats was occluded (90 min) and following reperfusion (24 h), mesenteric resistance arteries were dissected. Vascular reactivity was studied using wire myography. Protein and mRNA expression, superoxide anion (O2•−) production and ET-1 plasma concentration were evaluated by immunofluorescence, real-time quantitative PCR,…
Different β-adrenoceptor subtypes coupling to cAMP or NO/cGMP pathways: implications in the relaxant response of rat conductance and resistance vesse…
2013
Background and Purpose To analyse the relative contribution of β1-, β2- and β3-adrenoceptors (Adrb) to vasodilatation in conductance and resistance vessels, assessing the role of cAMP and/or NO/cGMP signalling pathways. Experimental Approach Rat mesenteric resistance artery (MRA) and aorta were used to analyse the Adrb expression by real-time-PCR and immunohistochemistry, and for the pharmacological characterization of Adrb-mediated activity by wire myography and tissue nucleotide accumulation. Key Results The mRNAs and protein for all Adrb were identified in endothelium and/or smooth muscle cells (SMCs) in both vessels. In MRA, Adrb1 signalled through cAMP, Adrb3 through both cAMP and cGMP…
Cigarette smoke exposure up-regulates endothelin receptor B in human pulmonary artery endothelial cells: molecular and functional consequences
2010
BACKGROUND AND PURPOSE Pulmonary arteries from smokers and chronic obstructive pulmonary disease patients show abnormal endothelium-dependent vascular reactivity. We studied the effect of cigarette smoke extract (CSE) on endothelin receptor B (ETB) expression in human pulmonary artery endothelial cells (HPAECs) and its role in endothelial dysfunction. EXPERIMENTAL APPROACH ETB receptor expression was measured by real time RT-PCR, Western blot and immunofluorescence. Cell contraction, intracellular Ca2+, F/G-actin, RhoA activity, myosin light chain phosphorylation, ET, NO, thromboxane (Tx)A2 and reactive oxygen species (ROS) were measured by traction microscopy, fluorescence microscopy, phal…