Search results for "Mesenteric Arteries"
showing 10 items of 28 documents
Role of endothelial nitric oxide in pulmonary and systemic arteries during hypoxia
2014
Abstract Our aim was to investigate the role played by endothelial nitric oxide (NO) during acute vascular response to hypoxia, as a modulator of both vascular tone (through guanylate cyclase (sGC) activation) and mitochondrial O2 consumption (through competitive inhibition of cytochrome-c-oxydase (CcO)). Organ bath experiments were performed and O2 consumption (Clark electrode) was determined in isolated aorta, mesenteric and pulmonary arteries of rats and eNOS-knockout mice. All pre-contracted vessels exhibited a triphasic hypoxic response consisting of an initial transient contraction (not observed in vessels from eNOS-knockout mice) followed by relaxation and subsequent sustained contra…
Role of the Endothelium in the Relaxation Induced by Propofol and Thiopental in Isolated Arteries from Man
1997
Abstract Induction of anaesthesia with intravenous propofol and thiopental is often accompanied by hypotension. This study evaluates whether propofol and thiopental induce relaxation of isolated arteries from man and whether this effect is modulated by the endothelium. Mesenteric artery rings (with and without endothelium) from 12 patients were placed in organ baths and precontracted with phenylephrine before addition of propofol (10−3 M) or thiopental (10−3 M). Relaxation induced by propofol and thiopental was evaluated for rings with intact endothelium in the presence of the nitric oxide synthase inhibitor NG-nitro-l-arginine methyl ester (l-NAME; 10−4 M) or the cyclooxygenase inhibitor i…
Endothelial kinin B1‐receptors are induced by myocardial ischaemia‐reperfusion in the rabbit
2001
Kinin B1-receptors are induced by various inflammatory stimuli. Since myocardial ischaemia-reperfusion results in inflammation, we questioned whether it could induce B1-receptor-dependent responses to des-Arg9-bradykinin (DBK). Thirty-six rabbits were submitted either to a 30 min coronary occlusion followed by a 3 h reperfusion or to a sham operation. The response to DBK was then tested in vivo on mean arterial pressure (MAP) and in vitro on isolated hearts and arterial rings. DBK induced a dose-dependent decrease in MAP in the ischaemia-reperfusion group (DBK, 10 μg kg−1, intra-arterial: -12 ± 2 vs. -5 ± 2 mmHg in the sham group, P < 0.02), which was significantly antagonised by [Leu8]-des…
Heterogeneity of atherosclerosis in mesenteric arteries and outgrowth remodeling
2009
Abstract Background In patients with acute mesenteric ischemia by occlusive thrombo-embolism, the superior mesenteric artery (SMA) is more affected than the inferior mesenteric artery (IMA). Methods This study investigated postmortem mesenteric arteries from aged subjects (n=21). Four atherosclerotic stages were defined by signs of degeneration and inflammation in sections stained with Elastica-van-Gieson and immunohistology, respectively. Results In females and males, Stages 3 and 4 were found in 62% of the SMA and 24% of the IMA. Lumenal areas based on diameter measurements remained essentially unchanged between Stages 1 and 4. Compared to a Stage 1 reference, remodeling was associated wi…
Comparative effects of the novel vasotocin analogue F-180 vs. vasopressin and terlipressin on systemic and splanchnic isolated vessels from portal hy…
2001
F-180 has been proposed as a new vasopressin analogue for the treatment of portal hypertension. This study investigates the contractile profile of F-180 compared to vasopressin and its analogue terlipressin on isolated systemic and splanchnic vessels from sham-operated and partial portal vein ligated (PPVL) rats. F-180 (10(-9)-10(-6) M), vasopressin (10(-11)-10(-8) M) and terlipressin (10(-9)-10(-4) M) induced contraction of the mesenteric vein, aorta, iliac, tail and mesenteric arteries. The order of potency in these vessels was vasopressin (pD2 approximately 9)F-180 (pD2 approximately 8)terlipressin (pD2 approximately 6). Significant (P0.01) differences between sham-operated and PPVL rats…
Arrhythmic sudden cardiac death in a 3-year-old child with intimal fibroplasia of coronary arteries, aorta, and its branches
2001
Abstract We report an unusual case of “arrhythmic” sudden cardiac death in a 3-year-old child who died of ischemic myocardial lesions as a result of intimal fibroplasia of the coronary arteries. Also affected were the aorta and its major branches, whereas renal and mesenteric arteries, celiac trunk, and systemic veins were normal. Histopathologic examination showed severe concentric thickening of intima because of a proliferation of spindle-shaped cells (mesenchymal cells) set in an abundant extracellular matrix. In some vascular segments the intima was densely fibrotic and hyalinized. No significant inflammation, foam cells, cholesterol clefts, or other evidence of atheroma were present. T…
Milrinone is preferred to levosimendan for mesenteric perfusion in hypoxia-reoxygenated newborn piglets treated with dopamine
2012
INTRODUCTION There is little information regarding the comparative hemodynamic effects of adding milrinone or levosimendan to dopamine infusion in hypoxia-reoxygenated (H-R) newborns. RESULTS Severely hypoxic piglets had cardiogenic shock with depressed cardiac index (CI) and mean arterial pressure (MAP). The hemodynamics deteriorated gradually after initial recovery upon reoxygenation. Heart rate and CI improved with milrinone (D+M) and levosimendan (D+L) administration (P < 0.05 vs. control). Both regimens improved carotid arterial flow and carotid vascular resistance; D+M additionally improved superior mesentric arterial flow (all P < 0.05 vs. control). No effect was found on renal arter…
Increased endothelin-1 vasoconstriction in mesenteric resistance arteries after superior mesenteric ischaemia-reperfusion
2012
BACKGROUND AND PURPOSE Endothelin-1 (ET-1) plays an important role in the maintenance of vascular tone. We aimed to evaluate the influence of superior mesenteric artery (SMA) ischaemia-reperfusion (I/R) on mesenteric resistance artery vasomotor function and the mechanism involved in the changes in vascular responses to ET-1. EXPERIMENTAL APPROACH SMA from male Sprague-Dawley rats was occluded (90 min) and following reperfusion (24 h), mesenteric resistance arteries were dissected. Vascular reactivity was studied using wire myography. Protein and mRNA expression, superoxide anion (O2•−) production and ET-1 plasma concentration were evaluated by immunofluorescence, real-time quantitative PCR,…
Different β-adrenoceptor subtypes coupling to cAMP or NO/cGMP pathways: implications in the relaxant response of rat conductance and resistance vesse…
2013
Background and Purpose To analyse the relative contribution of β1-, β2- and β3-adrenoceptors (Adrb) to vasodilatation in conductance and resistance vessels, assessing the role of cAMP and/or NO/cGMP signalling pathways. Experimental Approach Rat mesenteric resistance artery (MRA) and aorta were used to analyse the Adrb expression by real-time-PCR and immunohistochemistry, and for the pharmacological characterization of Adrb-mediated activity by wire myography and tissue nucleotide accumulation. Key Results The mRNAs and protein for all Adrb were identified in endothelium and/or smooth muscle cells (SMCs) in both vessels. In MRA, Adrb1 signalled through cAMP, Adrb3 through both cAMP and cGMP…
Relaxant effects of antidepressants on human isolated mesenteric arteries
1999
Aims The therapeutic action of tricyclic agents may be accompanied by unwanted effects on the cardiovascular system. The evidence for the effects on vascular and nonvascular smooth muscle comes from animal studies. Whether these studies can be extrapolated to human vessels remains to be determined. Therefore, the present study was designed to investigate the influence of amitriptyline, nortriptyline and sertraline on the contractile responses of human isolated mesenteric arteries to electrical field stimulation, noradrenaline and potassium chloride. Methods Arterial segments (lumen diameter 0.8–1.2 mm) were obtained from portions of the human omentum during the course of 41 abdominal operat…