Search results for "Vasodilator Agents"
showing 10 items of 116 documents
Relaxant effect of sildenafil in the rabbit basilar artery
2005
We hypothesized that sildenafil, inhibitor of phosphodiesterase-5 (PDE-5), interacts with the nitric oxide (NO)-cGMP pathway in the cerebral arteries and shows vasoactive effects. To prove it in the isolated rabbit basilar artery, we compared the effects of sildenafil with other PDE-5 inhibitors, assessed the endothelial dependence of the vasoactive responses, and used modulators of the cGMP and cAMP signaling processes. Sildenafil (10 nM-0.1 mM) induced concentration-dependent relaxations of endothelin-1 (10 nM)-precontracted basilar artery, which were partially inhibited both in endothelium-denuded arteries and in arteries precontracted by depolarization with KCl (50 mM). Endothelin-1 (1 …
EFFECTS OF PHORBOL 12,13-DIACETATE AND ITS INFLUENCE ON SPASMOGENIC RESPONSES IN NORMAL AND SENSITIZED GUINEA-PIG TRACHEA
1995
Abstract We have studied the effects of phorbol 12,13-diacetate (PDA) and its influence on a variety of spasmogenic responses in trachea isolated in from normal and sensitized guinea-pigs. Tracheal preparations were denuded of epithelium, treated with indomethacin (2·8 μm), and cooled to 20°C. In these experimental conditions, tracheal strips contracted to PDA (0·1 nm-1 μm). Contractions to PDA (1 μm) were greater in sensitized tissues. In normal trachea, contractions to PDA (0·1 μm) were depressed by H-7, 1-(5-isoquinolinyl-sulphonyl)-2-methylpiperazine, (50 μm), amiloride (10 μm), verapamil (10 μm) and Ca2+-free exposure. Similar effects were obtained in sensitized trachea except that PDA…
The Effects of Sodium Nitroprusside-Induced Hypotension on Splanchnic Perfusion and Hepatocellular Integrity
1999
UNLABELLED The purpose of our study was to investigate the effects of sodium nitroprusside-induced hypotension on splanchnic perfusion and hepatocellular integrity. Thirty patients undergoing radical prostatectomy were allocated randomly to a sodium nitroprusside (SNP) or control group (control). Regional pco2 was measured using gastric tonometry, and the regional to arterial difference in partial pressure of CO2 and intramucosal pH were calculated. The cytosolic liver enzyme alpha-glutathione S-transferase and standard liver enzyme markers (alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyltransferase) were also measured. Mean arterial pressure in the SNP group was 50…
Effect of intraarterial papaverine or nimodipine on vessel diameter in patients with cerebral vasospasm after subarachnoid hemorrhage.
2012
Papaverine (P) and nimodipine (N) are the most widely used vasodilators when angiographic and symptomatic vasospasm is present after subarachnoid aneurysmatic hemorrhage (SAH). Their effect is only short-lived and no direct comparisons have been undertaken to evaluate the action of both substances directly. We retrospectively assessed the effect of either P or N on angiographic diameter reduction and capillary blood flow.Fifteen SAH patients with secured aneurysms and cerebral vasospasm received intraarterial P, fifteen similar patients received N. As the primary endpoint, pre- and post-infusion arterial diameters and capillary blood flow were rated retrospectively on angiographies and comp…
No improvement in perfusion and oxygenation of experimental tumors upon application of vasodilator drugs
2001
The oxygen deficiency seen in solid tumors is predominantly caused by an insufficient O2 supply as a result of inadequate tumor perfusion. The aim of this study was to analyze whether a number of vasodilator drugs might be suitable to increase tumor perfusion and consequently improve the oxygenation status of experimental tumors. Rats with s.c. DS-sarcomas were treated with either Na+-nitroprusside (7-25 microg x min(-1) x kg(-1) BW) or nifedipine (10 microg x min(-1) x kg(-1) BW). Red blood cell (RBC) flux was assessed continuously using laser-Doppler flowmetry and mean tumor pO2 was measured polarographically using O2-sensitive catheter electrodes. Systemic application of the vasodilator …
The Effects of Prostaglandin E-1 in Patients with Intermittent Claudication
2006
Aim of the study is to evaluate the effects of Prostaglandin E-1 (PGE-1) in patients with peripheral arterial disease (PAD) at the 2nd b stage Fontaines classification. The study, controlled, single blinded, enrolled 123 patients with intermittent claudication that were randomised in two groups; the first group received a treatment with PGE-1 while the second one received a pentoxifylline-buflomedil association by venous infusion. We evaluated: Pain Free Walking Distance (PFWD), Maximum Walking Distance (MWD), Rest Flow (RF), Peak Flow (PF), Basal (BVR) and Minimal Vascular Resistance (MVR) with a strain gauge plethysmograph, Resting Flow (RF), Peak Flow (PF), time to reach the Peak Flow (t…
[Diagnosis, prognosis and treatment of "myocardial bridging": state of the art and unresolved issues].
2013
The current gold standard for the diagnosis of myocardial bridging is conventional coronary angiography; however, it shows only indirect signs of the disease, due to the systolic compression of the artery caused by the myocardial bridge with narrowing of the lumen and diastolic relaxation. On the other hand, computed tomography coronary angiography, even though exposing to radiation, clearly demonstrates the intramural course, the overlying muscular bands and the surrounding tissues also in asymptomatic patients and in absence of systolic compression. The prognosis of patients with myocardial bridge is usually good, but further studies are needed to evaluate the long-term prognosis of these…
Nitric oxide-mediated beta 2-adrenoceptor relaxation is impaired in mesenteric veins from portal-hypertensive rats.
1996
Abstract BACKGROUND & AIMS: beta-Adrenergic relaxation seems to be mediated by nitric oxide. The aim of this study was to evaluate changes induced by portal hypertension in beta 2-adrenergic vasorelaxation. METHODS: Isolated rat mesenteric veins were relaxed by salbutamol, and nerve- mediated vasocontractions were induced by electrical field stimulation. Responses were evaluated in the presence of NG-nitro-L-arginine methyl ester (L-NAME) or tetrodotoxin. Immunocytochemical techniques were used for localization of neuronal NO synthase. RESULTS: Salbutamol-induced relaxations were decreased in rings from portal-hypertensive animals. L- NAME reduced these relaxations, but its effects were mor…
β-Adrenoceptors differentially regulate vascular tone and angiogenesis of rat aorta via ERK1/2 and p38
2014
β-Adrenoceptors (β-ARs) modulate ERK1/2 and p38 in different cells, but little is known about the contribution of these signaling pathways to the function of β-ARs in vascular tissue. Immunoblotting analysis of rat aortic rings, primary endothelial (ECs) and smooth muscle cells (SMCs) isolated from aorta showed that β-AR stimulation with isoprenaline activated p38 in aortic rings and in both cultured cell types, whereas it had a dual effect on ERK1/2 phosphorylation, decreasing it in ECs while increasing it in SMCs. These effects were reversed by propranolol, which by itself increased p-ERK1/2 in ECs. Isoprenaline β-AR mediated vasodilation of aortic rings was potentiated by the ERK1/2 inhi…
Steroid and vasoactive treatment for acute deafness after attempted hearing preservation acoustic neuroma surgery.
2004
<i>Objective:</i> To investigate whether intravenous steroid and vasoactive therapy in the acute postoperative period improves hearing outcome in patients who develop acute deafness after attempted hearing preservation surgery for acoustic neuroma (AN) through a retrosigmoid or a middle cranial fossa approach. <i>Study Design and Setting:</i> Retrospective controlled study in a tertiary care center. Thirty-six patients who had developed acute deafness after hearing preservation surgery for treatment of an AN were reviewed. Preoperative AAOHNS hearing class was A in 2, B in 2 and D in 32 patients. Twenty-seven patients were treated with prednisolone, hydroxyethyl star…