Inflammatory and prothrombotic activation with conserved endothelial function in patients with chronic, asymptomatic Chagas disease.

Unlabelled: Previously, our group showed a prothrombotic state in asymptomatic patients with chronic Chagas disease. The current paper studies the inflammatory status and endothelial function in these patients.

Methods: In 40 patients and 40 healthy volunteers, we evaluated prothrombotic state, blood parasitemia (molecular biology: polymerized chain reaction [PCR]-amplification), tissue factor pathway inhibitor antibodies (aTFPI), interleukin 6 (IL-6), and vascular cell adhesion molecule-1 (VCAM-1).

Reactivity of isolated toad aortic rings to angiotension II: the role of nitric oxide.

Little is known about the vascular actions of angiotensin II (Ang II) and nitric oxide (NO) in Amphibia. This study investigated (1) Ang II contractility, (2) NO concentrations, and (3) correlations between Ang II contractility, NO concentration and mean arterial pressure (MAP) in isolated Bufo arenarum toad aortic rings. Contractility was measured in isometric conditions, NO concentrations were determined by the Griess reaction, and MAP was determined by a direct method.

Endothelial dysfunction and improvement of the angiotensin II-reactivity in hypercholesterolemic rabbits: role of cyclooxygenase metabolites.

The aim of this paper was to study the effect of high cholesterol diet on endothelial function and vascular reactivity to angiotensin II and to test the role of vasoconstrictor cyclooxygenase metabolites in this experimental condition. Rabbits were fed with either normal chow or a diet containing 1% cholesterol for 6-7-week. Isometric contractions were measured in rubbed or unrubbed aortic rings.

Internal mammary artery grafts reactivity in hypertensive patients: role of stretching in extraendothelial nitric oxide.

Background: The internal mammary artery (IMA) used in bypass coronary surgery remains efficient for a longer time than other grafts, such as saphenous veins; however, its biological characteristics are incompletely defined.

Objective: To compare in IMA grafts from hypertensive (HT) and normotensive (NT) patients the presence of endothelium and their functionability, the response to passive stretching and basal tone, the reactivity to exogenous vasoconstrictors, the role of stretching in NO release, and the possible extraendothelial NO source.

Methods And Results: IMA rings contractility, presence of endothelium, and nitrite release were studied.

Increased NADPH oxidase activity mediates spontaneous aortic tone in genetically hypertensive rats.

NADPH oxidase is critically involved in increased blood pressure, vascular hypertrophy, inflammation and endothelial dysfunction in experimental and clinical hypertension. We hypothesized that NADPH oxidase might also play a role in the development of spontaneous aortic tone in spontaneously hypertensive rats (SHR). Wistar Kyoto rats (WKY) were used as normotensive controls.

Nitric oxide modulates angiotensin II-induced endothelial vasoconstrictor prostanoid release.

Unlabelled: This study investigated the modulation of angiotensin II-induced endothelial prostanoid release in rabbit aortic rings. Two cumulative dose response curves with 90-min washing interval were performed. Incubation with L-N(G)-nitroarginine methyl ester (L-NAME) 10(-4) M increased angiotensin II maximal contractile response (E(max)).

Structural changes in the renal vasculature in streptozotocin-induced diabetic rats without hypertension.

Background/aim: We evaluated in diabetic-streptozotocin rats (STZR) the structural changes of glomeruli, preglomerular vessels, glomerular tuft and renal parenchyma in order to determine the degree of renal injury and the presence of remodeling in afferent arterioles developed by diabetes without overimposed hypertension.

Methods: Renal mass index and histological score (glomerular number, density, tubular lesions and degree of arteriosclerosis) were estimated. In afferent arterioles the ratio of wall thickness/lumen was obtained by stereological methods.

Cross talk between angiotensin II and alpha 1 adrenergic receptors in rabbit aorta: role of endothelium.

Interaction between the renin-angiotensin system and the sympathetic nervous system has been proposed to be like a physiological regulation mechanism. The present work was designed to study the cross talk between angiotensin II and adrenergic receptors on the smooth muscle contractile response and the endothelium influence in this phenomenon. Homologous and endothelium independent desensitization of angiotensin II-contractile response was observed.

[The prothrombotic state in early stages of chronic chagas' disease].

Objective: This study was designed to explore the presence of a prothrombotic state in the early stages of chronic Chagas' disease by evaluating serum markers of thrombosis and fibrinolysis.

Patients And Method: Forty-two patients with chronic Chagas' disease (12 men and 30 women, 32.5 6.

The novel serine protease PreR-Co promotes endothelium-independent vasorelaxation in rabbit aortic rings.

The effect of a novel enzyme (PreR-Co) that activates renal prorenin was studied on rabbit aortas with and without endothelium. It was tested 1) in the basal tone of nonstimulated or ANG II-sensitized rings or rings precontracted with norepinephrine (NE), PGF(2alpha), high KCl concentration, and 2) in rings pretreated with enalaprilat, losartan, PD-123319, N(omega)-nitro-l-arginine methyl ester, HOE-140, indomethacin, or serine protease inhibitors (PMSF, aprotinin, or soybean trypsin inhibitor); kallilkrein and bradykinin were also tested in ANG II-sensitized rings. PreR-Co produced a vasorelaxant effect in the basal tone and in the precontracted rabbit aorta.

Role of nitric oxide on the vasorelaxant effect of atrial natriuretic peptide on rabbit aorta basal tone.

The role of nitric oxide (NO) on the vasorelaxant effect of atrial natriuretic peptide (ANP) on the basal tone of rabbit aortic rings conditioned to angiotensin II (Ang II) was studied. ANP aortic relaxation and nitrite release were measured in the presence and absence of endothelium and a NO-synthase inhibitor. Ang II at 10(-8) M triggered a contractile response, conditioning the vessel to a vasorelaxant effect of ANP (10(-8) M).