Search results for "endothelin-1"
showing 10 items of 40 documents
Endothelin-1 and endothelin receptor status in kidney transplants undergoing acute rejection.
1999
Abstract Endothelin-1 (ET-1) is a potent vasoconstrictor with vasopressor and mitogenic effects. Blood samples were collected from 21 renal transplant patients undergoing acute rejection at the time of diagnostic kidney biopsy: there were 20 men and one woman, mean age 35.6 years. All patients were on triple immunosuppressive therapy with cyclosporine A, azathioprine and methylprednisolone. Twenty living kidney donors pre-uninephrectomy (11 men and nine women, mean age 34 years) served as controls. Control kidney was obtained from fresh autopsy material and normal kidney tissue from nephrectomies for malignancy. Mean plasma ET-1 was significantly increased at 1.56±0.2 pg ml −1 during acute …
Endothelin-1 and F2-isoprostane relate to and predict renal dysfunction in hypertensive patients.
2008
Background. Hypertension and additional non-traditional risk factors can damage the kidney directly and by promoting atherogenesis. Evidence indicates that increased oxidative stress and inflammation may mediate a large part of the effects of risk factors on the kidney. We hypothesized that in hypertensive patients (HT), oxidative stress, measured as 8-ISO-prostaglandin F2alpha (8-ISO-PGF2alpha), should raise paralleling decreasing renal function and should correlate with estimated glomerular filtration rate (eGFR). Methods. In 626 HT with renal function ranging from stages 1 to 5 and 100 healthy controls, plasma levels of 8-ISO-PGF2alpha, high-sensitivity C-reactive protein (CRP), transfor…
Impairment of the modulatory role of nitric oxide on the endothelin-1-elicited contraction of cerebral arteries: a pathogenetic factor in cerebral va…
1997
OBJECTIVE: Nitric oxide (NO) and endothelin-1 (ET-1) are two endothelium-derived factors probably involved in the pathogenesis of cerebral vasospasm after subarachnoid hemorrhage (SAH). Our aim was twofold, i.e., to ascertain whether endothelial and nonendothelial NO modulates the contractile response of cerebral arteries to ET-1 and to analyze whether this relationship might be impaired after experimental SAH. METHODS: Rings of middle cerebral artery from goats in the control group and from goats with SAH were set up for isometric tension recordings. SAH was induced 3 days before the experiments by infusion of 10 ml of autologous arterial blood through a catheter previously inserted into t…
Ethanol inhibits astroglial cell proliferation by disruption of phospholipase D-mediated signaling.
2002
The activation of phospholipase D (PLD) is a common response to mitogenic stimuli in various cell types. As PLD-mediated signaling is known to be disrupted in the presence of ethanol, we tested whether PLD is involved in the ethanol-induced inhibition of cell proliferation in rat cortical primary astrocytes. Readdition of fetal calf serum (FCS) to serum-deprived astroglial cultures caused a rapid, threefold increase of PLD activity and a strong mitogenic response; both effects were dependent on tyrosine kinases but not on protein kinase C. Ethanol (0.1-2%) suppressed the FCS-induced, PLD-mediated formation of phosphatidic acid (PA) as well as astroglial cell proliferation in a concentration…
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…
Requirement of caveolae microdomains in extracellular signal-regulated kinase and focal adhesion kinase activation induced by endothelin-1 in primary…
1999
Endothelin-1 (ET-1) mitogenic activity in astrocytes is mediated by the activation of the extracellular signal-regulated kinase (ERK) pathway together with the Rho-dependent activation of the focal adhesion kinase (FAK) pathway. To clarify the mechanisms responsible for the coordinate activation of both pathways in the ET-1 signal propagation, the involvement of caveolae microdomains, suggested to play a role in signal transduction, was evaluated. In this study, it is reported that caveolae of primary astrocytes are enriched in endothelin receptor (ETB-R). Furthermore, signaling molecules such as the adaptor proteins Shc and Grb2, and the small G protein Rho, also reside within these microd…
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…
Different role of endothelin ETA and ETB receptors and endothelial modulators in diabetes-induced hyperreactivity of the rabbit carotid artery to end…
2004
The influence of diabetes on regulatory mechanisms and specific receptors implicated in the contractile response of isolated rabbit carotid arteries to endothelin-1 was examined. Endothelin-1 induced a concentration-dependent contraction that was greater in arteries from diabetic rabbits than in arteries from control rabbits. Endothelium removal or N(G)-nitro-L-arginine enhanced contractions in response to endothelin-1 only in control arteries, without modifying the endothelin-1 response in diabetic arteries. Indomethacin, furegrelate (thromboxane A(2) inhibitor), or cyclo-(D-Asp-Pro-D-Val-Leu-D-Trp) (BQ-123; endothelin ET(A) receptor antagonist) inhibited the contractions in response to en…
Chronic social defeat stress causes retinal vascular dysfunction
2021
Abstract Purpose The roles of vascular dysfunction and chronic stress have been extensively discussed in the pathophysiology of glaucoma. Our aim was to test whether chronic stress causes retinal vascular dysfunction and therewith induces retinal ganglion cells (RGCs) loss. Methods Twelve mice underwent chronic social defeat (CSD) stress, while 12 mice received control treatment only. Intraocular pressure (IOP) was measured with a rebound tonometer. Blood plasma corticosterone concentration and adrenal gland weight were used to assess stress levels. Brn-3a staining in retinas and PPD staining in optic nerve cross sections were conducted to assess the survival of RGCs and axons respectively.…
Endothelin Antagonism: Effects of FP Receptor Agonists Prostaglandin F2αand Fluprostenol on Trabecular Meshwork Contractility
2006
Purpose This study analyzes additional mechanisms behind the ocular hypotensive effect of prostaglandin F (PGF) receptor (FP receptor) agonists PGF2alpha and fluprostenol (fluprostenol-isopropyl ester [travoprost]), which reduce intraocular pressure (IOP) in patients with glaucoma probably by enhancing uveoscleral flow. The trabecular meshwork (TM) is actively involved in IOP regulation through contractile mechanisms. Contractility of TM is induced by endothelin (ET)-1, a possible pathogenic factor in glaucoma. The involvement of FP receptor agonists in the ET-1 effects on TM function was studied. Methods The effects of FP receptor agonists on contractility of bovine TM (BTM) were investiga…