Search results for "Prostacyclin"
showing 10 items of 60 documents
COX-2, Another Important Player in the Nitric Oxide–Endothelin Cross-Talk
2006
See related article, pages 1439–1445 Traditionally, the role of the endothelium was thought to be primarily that of a selective barrier to the diffusion of macromolecules from the vessel lumen to the interstitial space. During the past 20 years, numerous additional roles for the endothelium have been defined such as regulation of vascular tone, modulation of inflammation, promotion as well as inhibition of vascular growth, and modulation of platelet aggregation and coagulation. Endothelial dysfunction is a characteristic feature of patients with cardiovascular risk factors such as hypercholesterolemia, hypertension, diabetes mellitus, and chronic smoking. More recent studies indicate that i…
LSC Abstract – Lung-derived prostacyclin (PGI) in endothelial dysfunction in db/db mice
2016
Aim: Increased risk of pulmonary hypertension and not clear response of pulmonary endothelium to diabetes were reasons to compare nitric oxide (NO) and PGI-dependent function in pulmonary and systemic circulation in diabetes type II. Methods: In fasted db mice (male, 20 weeks) we compared the function of pulmonary (isolated perfused lung-IPL) and aortic endothelium (wire myograph). It was supported by determination of nitrite(NO 2 - )/nitrate(NO 3 - ), PGI production, immunostaining (IMS) and western blot. Results: In diabetic IPL NO-dependent modulation of hypoxic pulmonary vasoconstriction was impaired but filtration coefficient increased; response to U46619 was enhanced; cumulative gener…
Diminished Inhibition of Adhesion Molecule Expression in Prostacyclin Receptor Desensitized Human Platelets
1995
Long-term exposure of platelets to prostacyclin or iloprost (100nM, 3hr) results in receptor desensitization measured as decrease in 3H-iloprost binding sites by 47 +/- 14%. Desensitized platelets respond with an increased adhesion to endothelial cells. The mechanism of increased adhesiveness was studied by measuring the expression of the adhesion molecule CD62p (p-selectin; GMP140) on washed human platelets by flowcytometry. In thrombin stimulated platelets CD62p expression was dose-dependently reduced by iloprost. In receptor desensitized platelets IC50 for iloprost inhibition of thrombin-induced CD62p expression increased from 0.48 +/- 0.10 to 2.4 +/- 0.7 nM.
Effect of the stable prostacyclin analogue iloprost on water and electrolyte transfer of the rat ileum and colon in vivo.
1988
The effect of iloprost on water and ion transfer was measured simultaneously in tied-off loops of the rat ileum and colon in vivo. (1) In the ileal loops iloprost had no effect on water and ion transfer neither by intraluminal, nor intraaortal or intravenous application. (2) In the colonic loops only intraaortal bolus application of the high dose of 500 micrograms iloprost significantly decreased net water, sodium and chloride absorption, but did not induce net secretion. (3) Inhibition of endogenous prostaglandin synthesis by indomethacin did not change net water and electrolyte transfer in the ileum and colon. (4) Under this pretreatment i.v.-application of 100 micrograms iloprost, ineffe…
Analysis of Rabbit Vascular Responses to DBI, an Ingol Derivative Isolated from Euphorbia canariensis
1997
Abstract We have analysed the effects of 7,12-O-diacetyl-8-O-benzoil-2,3-diepiingol (DBI), an ingol derivative isolated from E. canariensis, on isometric tension developed by isolated rabbit basilar and carotid arteries. Concentration-response curves to DBI (10−8 - 3 × 10−5 m) were obtained cumulatively in both arteries at resting tension and active tone (KC1, 50 mm). At resting tension, DBI induced a concentration-dependent contraction, which was not inhibited in Ca2+-free medium. H7 (1-(5-isoquinoline sulphonyl)-2-methylpiperazine dichloride) (10−4 m) inhibited the DBI-induced contraction both in basilar and in carotid arteries. Calmidazolium (10−4 m) inhibited the maximum contraction of …
Raloxifene promotes prostacyclin release in human endothelial cells through a mechanism that involves cyclooxygenase-1 and -2
2005
Objective To examine the effects of raloxifene on prostacyclin production by human umbilical vein endothelial cells (HUVEC) and to shed light on the molecular details of that action. Design Cell culture for 4, 8, 16, 24, and 48 hours. Setting University research laboratory. Patient(s) Source of HUVEC. Intervention(s) Measurement of prostacyclin production and of protein levels and mRNA expression of cyclooxygenase (COX)-1 and -2. Main Outcome Measure(s) Prostacyclin production was measured by enzyme immunoassay, the mRNA expression of COX-1 was measured by quantitative real time-polymerase chain reaction, and the protein levels of COX-1 and -2 were measured by immunoblotting. Result(s) Ralo…
Isoflavones and cardiovascular disease
2010
The specific profile of estrogens on cardiovascular risk, with limiting action on atherogenesis but a less clear protection on cardiovascular episodes, might be improved by other agonists of the estrogen receptor, such as isoflavones. By using a systematic search based on the electronic Medline database plus a hand-search of reference lists of selected review papers, we reviewed the rapidly growing body of experimental and clinical data that, on average, follow a pattern of benefit rather similar to estrogens. Experimental models have used endothelial and vascular smooth muscle cells, isolated arteries, and live animals, including monkeys. The clinical evidence arises from studies on the li…
Vascular aging in women: is estrogen the fountain of youth?
2012
Aging is a physiological process associated with structural and functional changes in vasculature, including endothelial dysfunction, arterial stiffening and remodeling, impaired angiogenesis, and defective vascular repair, and with an increasing prevalence of atherosclerosis. The risk of cardiovascular disease differs between men and women, remaining lower in women during their fertile years and reaching values similar to their male peers after menopause. Menopause is marked by the loss of endogenous estrogen production. Therefore, estrogens have been implicated in premenopausal protection from cardiovascular disease, an assumption supported by experimental and some clinical studies, where…
Antiproliferative effects of drugs affecting different signalling pathways on rat and human pulmonary artery smooth muscle cells
2015
Current treatments for pulmonary arterial hypertension (PAH) include pulmonary vasodilators which may also inhibit PASMC proliferation. The aim of this study was to compare the antiproliferative effects of multiple drugs on rat and human PASMC (rPASMC and hPMASC, respectively) in vitro. rPASMCs and hPASMC were starved for 24 h, then treated with different inhibitors and incubated for 48 h in 1% foetal calf serum plus endothelin-1, 5-HT and U46619. Cell number was estimated by the MTT test. Viable cells increased by 160-180% in 48 h. Activation of the cGMP pathway with the soluble guanylyl cyclase activators riociguat and YC-1 (≤ 10 µM) or the cAMP pathway by the adenylyl cyclase activator f…
Prostanoid release of cultured liver sinusoidal endothelial cells in response to endotoxin and tumor necrosis factor
1990
Abstract Vascular endothelial cells release prostanoids, especially prostacyclin, when properly stimulated. In addition to short acting stimuli like thrombin and histamine an increased prostanoid release occurs in the presence of endotoxin, interleukin 1 or tumor necrosis factor (TNF). The response of sinusoidal endothelial liver cells to such stimuli — probably important in hepatic inflammatory disease — is unknown. Sinusoidal endothelial liver cells from the guinea pig were isolated by centrifugal elutriation and investigated as confluent monolayers. Their prostanoid release in response to endotoxin and human recombinant TNF was determined by radioimmunoassays and compared to that obtaine…