Search results for "endothelin"
showing 10 items of 93 documents
High plasma levels of endothelin-1 enhance the predictive value of preclinical atherosclerosis for future cerebrovascular and cardiovascular events: …
2014
BACKGROUND AND PURPOSE: Clinical and experimental evidence suggests that endothelin-1 (Et-1) plays a role in cardiac and vascular disease. In the present study, we investigated the prognostic significance of Et-1 for cerebrovascular and cardiovascular outcome, in a 20-year follow-up. METHODS: We studied 82 originally healthy individuals, referred to our Unit of Cardiovascular Prevention, to evaluate the presence of asymptomatic carotid lesions. We subdivided these individuals into two groups, according to the plasma values of Et-1 (respectively ≤ or >2.7 pg/ml). Traditional cardiovascular risk factors were investigated, and by carotid ultrasound examination, we distinguished between normal …
Relationship of fetuin-A with glomerular filtration rate and endothelial dysfunction in moderate-severe chronic kidney disease
2010
Background: In end-stage renal disease, fetuin-A has been demonstrated to be reduced and inversely related to cardiovascular mortality. This study had 2 distinct aims. The first was to verify if circulating concentration of fetuin-A may depend on renal function in patients with chronic kidney disease (CKD). Furthermore, we analyzed the correlation of fetuin-A with the biomarker of endothelial dysfunction endothelin-1 (ET-1), and with the inflammatory cytokine interleukin-6 (IL-6). Methods: In 108 subjects with stage 3-5 CKD, plasma levels of fetuin-A, ET-1 and IL-6 were assayed. Patients were studied first as a whole group and then were divided according to stages of CKD and fetuin-A tertil…
Anti-Hypotensive Treatment and Endothelin Blockade Synergistically Antagonize Exercise Fatigue in Rats under Simulated High Altitude
2013
Rapid ascent to high altitude causes illness and fatigue, and there is a demand for effective acute treatments to alleviate such effects. We hypothesized that increased oxygen delivery to the tissue using a combination of a hypertensive agent and an endothelin receptor A antagonist drugs would limit exercise-induced fatigue at simulated high altitude. Our data showed that the combination of 0.1 mg/kg ambrisentan with either 20 mg/kg ephedrine or 10 mg/kg methylphenidate significantly improved exercise duration in rats at simulated altitude of 4,267 m, whereas the individual compounds did not. In normoxic, anesthetized rats, ephedrine alone and in combination with ambrisentan increased heart…
Mast cells promote homeostasis by limiting endothelin-1-induced toxicity
2004
Endothelin-1 (ET-1) is a 21-amino-acid peptide, derived from vascular endothelial cells, with potent vasoconstrictor activity. ET-1 has been implicated in diverse physiological or pathological processes, including the vascular changes associated with sepsis. However, the factors that regulate ET-1-associated toxicity during bacterial infections, or in other settings, are not fully understood. Both the pathology associated with certain allergic and autoimmune disorders, and optimal host defence against bacterial and parasitic infections are mediated by mast cells. In vitro, mast cells can produce ET-1 (ref. 11), undergo ET-1-dependent and endothelin-A receptor (ET(A))-dependent activation, a…
Inflammatory Murine Skin Responses to UV-B Light Are Partially Dependent on Endothelin-1 and Mast Cells
2006
Endothelin (ET-1) has been shown to crucially contribute to UV-induced skin responses such as tanning. To test whether ET-1 is also involved in early cutaneous reactions to UV, we assessed ET-1 skin levels in UV-irradiated mice. In correlation with the levels of UV-induced skin inflammation, ET-1 concentrations increased substantially and continually. Moreover, blocking of ET-1 receptors (ET A ) resulted in significantly decreased cutaneous inflammation following UV irradiation. When we assessed skin responses to ET-1 injections, we observed prominent mast cell degranulation and mast cell-dependent inflammation. Since mast cells also critically contributed to UV-induced inflammation, we det…
Experimental Study of the Effects of EIPA, Losartan, and BQ-123 on Electrophysiological Changes Induced by Myocardial Stretch
2015
[ES] Introducción y objetivos Se han implicado diversos mecanismos en la respuesta mecánica al estiramiento miocárdico, que incluyen la activación del intercambiador Na+/H+ por acciones autocrinas y paracrinas. Se estudia la participación de estos mecanismos en las respuestas electrofisiológicas al estiramiento agudo miocárdico mediante el análisis de los cambios inducidos con fármacos. Métodos Se analizan las modificaciones de la fibrilación ventricular inducidas por el estiramiento agudo miocárdico en corazones de conejo aislados y perfundidos utilizando electrodos múltiples epicárdicos y técnicas cartográficas. Se estudian 4 series: control (n = 9); durante la perfusión del antagonista d…
Mechanisms underlying diabetes enhancement of endothelin-1-induced contraction in rabbit basilar artery
2004
The influence of alloxan-induced diabetes on the reactivity of rabbit basilar artery to endothelin-1 was examined. Endothelin-1 induced concentration-dependent contraction of basilar arteries that was higher in diabetic than in control rabbits. Endothelium removal produced a higher enhancement of the endothelin-1-induced contraction in control than in diabetic rabbits. N(G)-nitro-L-arginine (L-NOArg) enhanced the maximal contraction induced by endothelin-1 in control rabbits and potentiated this response in diabetic rabbits. Endothelin ETA receptor antagonist, cyclo(D-Asp-Pro-D-Val-Leu-D-Trp) (BQ-123), inhibited endothelin-1-induced contraction in both rabbit groups. Endothelin ETB receptor…
Intravenous BQ-123 and phosphoramidon reduce ventricular ectopic beats and myocardial infarct size in dogs submitted to coronary occlusion and reperf…
2001
Abstract The aim of this work was to investigate the influence of endothelin on myocardial ischemia and reperfusion in anaesthetized dogs. Animals were submitted to left thoracotomy and 120 min of left anterior descending coronary occlusion, followed by 180 min of reperfusion. Arterial blood pressure and electrocardiogram (ECG) were recorded in order to analyze heart rate (HR)–pressure product and production of ectopic beats. Infarcted areas were identified by a macroscopic staining method and infarct size was expressed as percentage of risk zone. To inhibit the effects of endothelin in a group of animals, we administered intravenously an endothelin synthesis inhibitor (phosphoramidon) and …
Subtype-specific endothelin-A and endothelin-B receptor desensitization correlates with differential receptor phosphorylation.
1998
In the rat cardiovascular system endothelin-1 (ET-1) elicits prolonged physiologic responses mediated by the ET A receptor, whereas the effects mediated by the ET B receptor are transient. The molecular mechanisms for the subtype-specific responses are not yet clear. However, post-translational modifications such as phosphorylation and palmitoylation may play an important role. In Sf9 cells overexpressing the human ET A and ET B receptors, both subtypes are palmitoylated. However, only the ET B but not the ET A receptor is phosphorylated in a ligand-dependent manner. Because phosphorylation is believed to play an important role in ligand-dependent receptor inactivation, we analyzed whether …
Endothelin-1 modulates the expression of adhesion molecules on fibroblast-like synovial cells (FLS)
1996
Endothelin-1 is known to possess various biological properties. In the present study we have investigated the effects of Endothelin-1 (Et-1) on the expression of adhesion molecules ICAM-1, VCAM-1 and CD-44 by fibroblast-like synoviocytes. Cultured fibroblast-like synoviocytes were treated with Et-1 in the absence or presence of C1306, a specific endothelin-A-receptor antagonist. Cell surface expression of ICAM-1, VCAM-1 and CD-44 was determined by immunofluorescence studies, Cyto-ELISA and FACS-analysis. ICAM-1, VCAM-1 and CD-44 were constitutively expressed on cultured FLS. After incubation with Et-1 the expression of ICAM-1, VCAM-1 and CD-44 increased. The level of expression of adhesion …