The aim of the present study was to analyze possible involvement vasoconstrictors prostanoids on reduced endothelium-dependent relaxations produced by chronic administration aldosterone in Wistar Kyoto rats (WKY) and spontaneously hypertensive (SHR). For this purpose, acetylcholine (ACh) aortic segments from both strains were analyzed absence presence cyclooxygenase-1 (COX-1) COX-2 inhibitor indomethacin, specific NS-398, TP receptor antagonist (SQ 29 548), thromboxane A 2 (TXA ) synthase...

We have previously described that chronic administration of ouabain induces hypertension and functional alterations in mesenteric resistance arteries. The aim this study was to analyze whether treatment also alters the structural mechanical properties Wistar rats were treated for 5 wk with (8.0 microg/day sc). vascular structure mechanics third-order branches artery assessed pressure myography confocal microscopy. Total collagen content determined by picrosirius red staining, I/III analyzed...

The present study was designed to assess whether cyclooxygenase-2 (COX-2) activation is involved in the effects of chronic aldosterone treatment on endothelial function mesenteric resistance arteries (MRA) from Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR).Relaxation acetylcholine measured MRA both untreated aldosterone-treated strains. Vasomotor responses prostacyclin U46619 were also analysed. Release 6-oxo-prostaglandin (PG)F1alpha thromboxane B2 (TxB2) determined by enzyme...

This study compares the role of endothelial factors in α ‐adrenoceptor contractile responses mesenteric resistance (MRA) and superior (SMA) arteries from ouabain‐treated (8.0 μ g day −1 , 5 weeks) untreated rats. The renin–angiotensin system was also evaluated. Ouabain treatment increased systolic blood pressure. In addition, ouabain reduced phenylephrine response SMA but did not alter noradrenaline MRA. Endothelium removal or nitric oxide synthase (NOS) inhibitor ( L ‐NAME, 100 M ) to...

<i>Background/Aims:</i> The purpose of this study was to examine the cardiovascular effects long-term ouabain treatment at different time points. <i>Methods:</i> Systolic blood pressure (SBP) measured by tail-cuff method in male Wistar rats treated with (approx. 8.0 µg·day<sup>–1</sup>) or vehicle for 5, 10 and 20 weeks. Afterwards, vascular function assessed mesenteric resistance arteries (MRA) using a wire myograph. ROS production COX-1 COX-2, TNF-α,...

This study analyzed the effect of in utero exposure to maternal diabetes on contraction noradrenaline mesenteric resistance arteries (MRA) from adult offspring, focusing role cyclooxygenase (COX)-derived prostanoids. Diabetes rat was induced by a single injection streptozotocin (50 mg/kg body weight) day 7 pregnancy. Contraction isolated MRA offspring diabetic (O-DR) and non-diabetic (O-CR) rats at 3, 6 12 months age. Release thromboxane A(2) (TxA(2)) prostaglandins E(2) (PGE(2)) F(2α)...

Neuronal NO plays a functional role in many vascular tissues, including MAs (mesenteric arteries). Glucocorticoids alter release from endothelium and the CNS (central nervous system), but no results peripheral innervation have been reported. In present study we investigated effects of dexamethasone on EFS (electrical field stimulation)-induced WKY (Wistar–Kyoto) rats SHRs (spontaneously hypertensive rats) PKC (protein kinase C) this response. endothelium-denuded MAs, L-NAME...

This study investigated the cardiovascular responses to essential oil of Aniba canelilla (EOAC) and its main constituent 1-nitro-2-phenylethane (NP) in spontaneously hypertensive rats (SHRs). In anesthetized SHRs, intravenous (i.v.) bolus injections EOAC (1–20 mg/kg) or NP (1–10 elicited dose-dependent hypotensive bradycardiac effects, which were characterized two periods (phases 1 2). The first rapid component (phase 1) evoked by both at 10 mg/kg was absent after left ventricle injection,...

Ageing impairs endothelial function, which is considered a hallmark of the development cardiovascular diseases in elderly. Cilostazol, phosphodiesterase-3 inhibitor, has antiplatelet, antithrombotic and protective effects on cells. Here, we hypothesized that cilostazol could improve function mesenteric resistance arteries (MRA) from old rats. Using eight-week cilostazol-treated (100mg/kg/day) or untreated 72-week-old Wistar rats, evaluate relaxation to acetylcholine, sodium nitroprusside...

The role of sympathetic nerve activity in the changes arterial blood pressure and renal function caused by chronic administration NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor nitric oxide (NO) synthesis, was examined sham bilaterally denervated rats. Several studies have demonstrated that is elevated acutely after L-NAME administration. To evaluate L-NAME-induced hypertension, we compared response four groups (N = 10 each) male Wistar-Hannover rats weighing 200 to 250 g: 1)...

Renin–angiotensin and endothelin systems are involved in the cardiovascular effects produced by treatment with ouabain. We recently demonstrated that contractile response to phenylephrine is decreased ouabain‐treated rats. The present study investigated whether endothelin‐1 (ET‐1) angiotensin II (Ang II) contributes vascular changes observed rats chronically treated Wistar were ouabain (8.0 μ g day −1 , s.c. pellets for 5 weeks) alone or combination an type A receptor (ET ) antagonist,...

Objectives We investigated whether chronic ouabain treatment changes the vasoconstrictor responses induced by electrical field stimulation (EFS) in endothelium-denuded rat superior mesenteric arteries and a possible role of neuronal nitric oxide (NO). Method Mesenteric from untreated ouabain-treated rats (≃8.0 μg/kg per day, for 5 weeks) were used this study. Vascular reactivity was analyzed isometric tension recording. Expression NO synthase isoform Western blot. Noradrenaline release...

Objective Hypertensive rats are more sensitive to the pressor effects of acute ouabain than normotensive rats. We analyzed effect chronic (∼8.0 μg/day, 5 weeks) treatment on blood pressure spontaneously hypertensive (SHRs) and Wistar–Kyoto contribution vascular mechanisms. Methods Responses acetylcholine phenylephrine were in isolated tail arteries. Protein expression endothelial nitric oxide synthase cyclooxygenase-2 (COX-2) also investigated. Results Ouabain enhanced only SHRs. The pD2 for...

Experimental studies and opinion articles emphasize that cardiovascular alterations associated with ageing can be improved by the long-term use of fenofibrates. We analyzed effect fenofibrate treatment on acetylcholine-induced relaxation in rat aorta participation nitric oxide (NO) cyclooxygenase (COX)-derived factors this effect.Acetylcholine untreated 6-week fenofibrate-treated Wistar rats was absence presence NO synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME),...

We have reported that exposure to a diabetic intrauterine environment during pregnancy increases blood pressure in adult offspring, but the mechanisms involved are not completely understood. This study was designed analyse possible role of perivascular sympathetic and nitrergic innervation superior mesenteric artery (SMA) this effect.Diabetes induced pregnant Wistar rats by single injection streptozotocin. Endothelium-denuded vascular rings from offspring control (O-CR) (O-DR) were used....

The effects of 1 nM ouabain (OUA) on the contractile actions phenylephrine (PHE, 0.001-100 microg) and functional activity sodium pump (NKA) in isolated-perfused tail vascular beds from WKY SHR were investigated. In preparations SHR, perfusion with OUA presence endothelium (E+) increased sensitivity (pED50) PHE (before: 2.14 +/- 0.06 versus after: 2.47 0.07; P < 0.05) without altering maximal response (Emax). After endothelial damage, reduced Emax 350 29 293 25 mm Hg; 0.05). SHR/E+,...