Search results for "Endothelium."
showing 10 items of 748 documents
Influence of Vascular Load on Plasma Endothelin-1, Cytokines and Catecholamine Levels in Essential Hypertensives
1998
In vitro studies demonstrated a relationship between ET-1 and basic Fibroblast Growth Factor (bFGF), and of bFGF with Platelet Derived Growth Factor (PDGF). The present study was carried out to investigate in vivo the behaviour after vascular stress of circulating ET-1, bFGF and PDGF, and catecholamines, and their relationship. In 12 healthy normotensives (NTs) and 15 essential hypertensives (Ehs) venous blood samples to determine circulating ET-1, bFGF and PDGF, and catecholamine (EPI and NE) levels were drawn before and at the third minute of a handgrip test. Blood pressures (BP) and heart rate were automatically recorded before starting, and at 1, 2, and 3 minutes during the test. The NT…
Estradiol, acting through estrogen receptor alpha, restores dimethylarginine dimethylaminohydrolase activity and nitric oxide production in oxLDL-tre…
2011
Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthase. ADMA accumulation, mainly due to a decreased dimethylarginine dimethylaminohydrolase (DDAH) activity, has been related to the development of cardiovascular diseases. We investigate whether estradiol prevents the changes induced by oxidized low density lipoprotein (oxLDL) on the DDAH/ADMA/NO pathway in human umbilical artery endothelial cells (HUAEC). HUAEC were exposed to estradiol, native LDL (nLDL), oxLDL and their combinations for 24 h. In some experiments, cells were also exposed to the unspecific estrogen receptor (ER) antagonist ICI 182780, the specific ERα antagonist MPP or specific agonists …
Kinin receptors in human vascular tissue: their role in atheromatous disease
1997
Using samples of many human blood vessels, obtained at autopsy and specific antibodies directed to peptide sequences of the kinin B1 and B2 receptors, we demonstrate the localisation of these receptors within the human vascular system using standard immunolabelling techniques. In large elastic arteries and veins, kinin receptors are present only in the endothelial cells whereas in all muscular arteries and arterioles, these receptors are present in both the endothelial and smooth muscle cells. The identification of kinin receptors in human blood vessels confirms that kinins may modulate both vascular permeability and contractility. The incidental finding at histology, of patchy atheromatous…
Angiotensin-Converting Enzyme Inhibitor Ramiprilat Interferes With the Sequestration of the B 2 Kinin Receptor Within the Plasma Membrane of Native E…
1999
Background —ACE (kininase II) inhibitors have been shown to exert their beneficial cardiovascular effects via the inhibition of both angiotensin II formation and bradykinin breakdown. Because recent evidence suggests that ACE inhibitors may also interfere with B 2 kinin receptor signaling and thus enhance the vascular response to bradykinin, we examined whether the distribution of B 2 kinin receptors within the plasma membrane of native endothelial cells is affected by an ACE inhibitor. Methods and Results —Localization of the B 2 kinin receptor in membranes prepared from native porcine aortic endothelial cells was evaluated by means of specific [ 3 H]bradykinin binding and immunoprecipita…
4-Hydroxynonenal-Induced Relaxation of Human Mesenteric Arteries1
1997
The effect of 4-hydroxynonenal (4-HNE), a circulating lipid peroxidation product, on the vascular tone of human mesenteric arteries is studied. 4-HNE promotes relaxation of human mesenteric arterial rings in a concentration-dependent manner. Removal of the endothelium or treatment with N(G)-nitro-L-arginine methyl ester hydrochloride (L-NAME; 10(-4) M) partially prevented 4-HNE-induced relaxation, thus suggesting the intervention of nitric oxide from endothelial origin in the vascular effects of 4-HNE.
Endothelial modulation of 5-hydroxytryptamine-induced contraction in goat cerebral arteries.
1993
Abstract 1. 1. In isolated goat middle cerebral artery segments, 5-hydroxytryptamine (5-HT, 10 −8 −3 × 10 −5 M) caused concentration-dependent contractions, with EC 50 = 2.1 (1.9−2.5) × 10 −7 M and E max = 60 ± 2% of 50 mM KCl-induced contraction. 2. 2. Mechanical removal of endothelium significantly increased the E max (91 ± 8%) and did not change the EC 50 value of 5-HT-elicited contractions. 3. 3. Incubation of unrubbed arteries with the irreversible inhibitor of EDRF, gossypol (10 −5 M), significantly increased the contractile response to 5-HT ( E max = 77 ± 4%). 4. 4. Incubation of unrubbed arteries with the competitive inhibitor of the NO synthesis, N G -nitro - l -arginine (L-NOARG) …
Magnesium and Type 2 Diabetes: An Update
2015
The link between magnesium (Mg) deficiency and type 2 diabetes mellitus is well known. Type 2 diabetes is frequently associated with both extracellular and intracellular Mg deficits. A chronic latent Mg deficit or an overt clinical hypomagnesaemia is common in subjects with type 2 diabetes, especially in those with poorly controlled glycemic profiles. Insulin and glucose are important regulators of Mg metabolism. Intracellular Mg plays a key role in regulating insulin action, insulin-mediated-glucose-uptake and vascular tone. Reduced intracellular Mg concentrations result in a defective tyrosine-kinase activity, postreceptorial impairment in insulin action and worsening of insulin resistanc…
A systematic review and meta-analysis of the effect of statins on plasma asymmetric dimethylarginine concentrations.
2015
AbstractThe impact of statin therapy on plasma asymmetric dimethylarginine (ADMA) levels has not been conclusively studied. Therefore the aim of the meta-analysis was to assess the effect of statins on circulating ADMA levels. We searched selected databases (up to August 2014) to identify randomized controlled trials (RCTs) that investigate the effect of statins on plasma ADMA concentrations. A weighted meta-regression (WMD) using unrestricted maximum likelihood model was performed to assess the impact of statin dose, duration of statin therapy and baseline ADMA concentrations as potential variables on the WMD between statin and placebo group. In total, 1134 participants in 9 selected RCTs …
Critical role of dipeptidyl peptidase IV in neuropeptide Y-mediated endothelial cell migration in response to wounding
2001
Recently, we have discovered that neuropeptide Y (NPY), a sympathetic neurotransmitter, is also present in human umbilical endothelial cells (HUVECs), and is potently chemotactic and angiogenic by acting on one or several of Y1-Y5 receptors. In HUVECs, NPY is co-localized with dipeptidyl peptidase IV (DPPIV) which cleaves Tyr(1)-Pro(2) from NPY(1-36) to form NPY(3-36) resulting in the formation of a non-Y1 receptor agonist, which remains angiogenic. Presently we studied the effects of DPPIV's blockade using monoclonal antibodies (mAbs) on migration of HUVECs in response to NPY(1-36) or NPY(3-36) following cell wounding. Both peptides caused similar dose-dependent increases in cell migration…
Glucose-induced loss of glycosyl-phosphatidylinositol-anchored membrane regulators of complement activation (CD59, CD55) by in vitro cultured human u…
2000
Aims/hypothesis. This study examines whether increased glucose concentrations are responsible for a decreased expression of membrane regulators of complement activation molecules. The effect of high glucose in determining an increase in membrane attack complex deposition on endothelial cells was also investigated. Methods. Endothelial cells were isolated from umbilical cord tissue, cultured in the presence of increased concentrations of glucose, and the expression of CD46, CD55, and CD59 was detected by ELISA (enzyme-linked immunosorbent assay) and by flow cytometry. Glucose-treated endothelial cells were also incubated with antiendothelial cell antibodies and fresh complement to assess the…