Search results for "Angiotensin"
showing 10 items of 396 documents
ACE inhibitor potentiation of bradykinin-induced venoconstriction
1997
1. Angiotensin-converting enzyme (ACE) inhibitors exert their cardiovascular effects not only by preventing the formation of angiotensin II (AII), but also by promoting the accumulation of bradykinin in or at the vessel wall. In addition, certain ACE inhibitors have been shown to augment the vasodilator response to bradykinin, presumably by an interaction at the level of the B2 receptor. We have investigated whether this is a specific effect of the ACE inhibitor class of compounds in isolated endothelium-denuded segments of the rabbit jugular vein where bradykinin elicits a constrictor response which is exclusively mediated by activation of the B2 receptor. 2. Moexiprilat and ramiprilat (< …
Effect of two phenanthrene alkaloids on angiotensin II-induced leukocyte-endothelial cell interactionsin vivo
2003
The present study has evaluated the effect of two phenanthrene alkaloids, uvariopsine and stephenanthrine, on angiotensin II (Ang-II)-induced leukocyte–endothelial cell interactions in vivo and the mechanisms involved in their activity. Intravital microscopy within the rat mesenteric microcirculation was used. A 60 min superfusion with 1 nM Ang-II induced a significant increase in the leukocyte–endothelial cell interactions that were completely inhibited by 1 μM uvariopsine cosuperfusion. A lower dose of 0.1 μM significantly reduced Ang-II-induced leukocyte adhesion by 75%. When Ang-II was cosuperfused with 1 and 0.1 μM stephenanthrine, Ang-II-induced leukocyte responses were significantly …
Angiotensin II is involved in nitric oxide synthase and cyclo-oxygenase inhibition-induced leukocyte-endothelialcell interactionsin vivo
2001
Chronic inhibition of nitric oxide synthase (NOS) provokes a hypertensive state which has been shown to be angiotensin II (Ang-II) dependent. In addition to raising blood pressure, NOS inhibition also causes leukocyte adhesion. The present study was designed to define the role of Ang-II in hypertension and in the leukocyte-endothelial cell interactions induced by acute NOS or cyclo-oxygenase (COX) inhibition using intravital microscopy within the rat mesenteric microcirculation. While pretreatment with an Ang-II AT1 receptor antagonist (losartan) reversed the prompt increase in mean arterial blood pressure (MABP) caused by indomethacin, it had no effect on the increase evoked by systemic L-…
Uncoupling of endothelial NO synthase in atherosclerosis and vascular disease.
2013
Nitric oxide (NO) produced by the endothelial NO synthase (eNOS) is an antihypertensive, antithrombotic and anti-atherosclerotic molecule. Hypercholesterolemia leads to a reduction in vascular NO bioavailability. This is attributed to a dysfunction of the eNOS enzyme and a reduced eNOS activity. NADPH oxidase-mediated oxidative stress leads to oxidation of tetrahydrobiopterin (BH4), the essential cofactor of eNOS. In BH4 deficiency, oxygen reduction uncouples from NO synthesis, thereby converting eNOS to a superoxide-producing enzyme. As a consequence of eNOS uncoupling, NO production is reduced and the pre-existing oxidative stress is enhanced, which contribute significantly to atherogenes…
Zum Einfluss von Angiotensin II auf die Nebennierenrinde unter chemischer adrenostase mit SU 4885 (Metopiron)
1964
The inhibition of 11-β-hydroxylase in the adrenal cortex with SU 4885 (metopiron) increases the ACTH-secretion. Val5-angiotensin II blocks the reaction of the anterior pituitary gland similarly as does dexamethasone. Mode and intensity of this action of angiotensin II, and the influence on rats treated as described, are studied.
Modifications induced in the renin-angiotensin-aldo-sterone system of rats by alpha-blocking drugs.
1978
Summary The data reported in the present paper refer to quantitative variations of plasma renin activity and plasma aldosterone levels after administration of alpha-blocking agents, i.e. phentolamine, phenoxybenzamine and gihydroergotoxin derivatives, either to rats kept on a standard diet with water ad libitum or to rats receiving distilled water load, the latter treatment causing an increase of both plasma renin activity and plasma aldosterone levels if compared to control values. No strict correlation between (a) drug-induced modifications of plasma renin activity and plasma aldosterone levels and (b) blood pressure drop caused by the same drugs was shown to occur under either experiment…
Cyclic AMP elevating agents and nitric oxide modulate angiotensin II-induced leukocyte-endothelial cell interactionsin vivo
2001
Angiotensin (Ang-II) is a key molecule in the development of cardiac ischaemic disorders and displays proinflammatory activity in vivo. Since intracellular cyclic nucleotides elevating agents have proved to be effective modulators of leukocyte recruitment, we have evaluated their effect on Ang-II-induced leukocyte-endothelial cell interactions in vivo using intravital microscopy within the rat mesenteric microcirculation. Pretreatment with iloprost significantly inhibited (1 nM) Ang-II-induced increase in leukocyte rolling flux, adhesion and emigration at 60 min by 96, 92 and 90% respectively, and returned leukocyte rolling velocity to basal levels. Pretreatment with salbutamol or co-superf…
Long-term treatment with the ace inhibitor captopril, alone or in combination with hydrochlorothiazide, in elderly hypertensives: Effects on blood pr…
1993
Abstract The efficacy and tolerability of long-term treatment with the angiotensin converting enzyme inhibitor captopril was evaluated in elderly hypertensive subjects. One hundred thirty patients were studied (61 men and 69 women; mean age, 68.33 ± 5.49 years), all with mild to moderate arterial hypertension (mild = 90–105 mmHg; moderate = 105–115 mmHg). Patients with secondary hypertension were excluded from the study. After a 2-week drug washout, patients were given captopril 25 to 100 mg/day alone or in combination with hydrochlorothiazide (HCTZ) 25 mg/day for 15 weeks. After 2 weeks of treatment, significant decreases in systolic and diastolic blood pressures were observed (P
Prescription patterns of angiotensin-converting enzyme inhibitors for various indications: A UK population-based study
2018
AIM: Angiotensin‐converting enzyme inhibitors (ACEIs) are widely prescribed for several cardiovascular indications. This study investigated patterns of ACEI use for various indications. METHODS: A descriptive, retrospective population‐based study was conducted using data from the UK Clinical Practice Research Datalink. Patients starting ACEIs (2007–2014) were selected and ACEI indications were retrieved from electronically recorded medical records. Stratified by indication, we distinguished between persistent and nonpersistent ACEI use, considering a 6‐month interval between two prescription periods as a maximum for persistent use. Five‐year persistence rates for various indications were ca…
Molecular Mechanisms of the Crosstalk Between Mitochondria and NADPH Oxidase Through Reactive Oxygen Species—Studies in White Blood Cells and in Anim…
2014
Aims: Oxidative stress is involved in the development of cardiovascular disease. There is a growing body of evidence for a crosstalk between different enzymatic sources of oxidative stress. With the present study, we sought to determine the underlying crosstalk mechanisms, the role of the mitochondrial permeability transition pore (mPTP), and its link to endothelial dysfunction. Results: NADPH oxidase (Nox) activation (oxidative burst and translocation of cytosolic Nox subunits) was observed in response to mitochondrial reactive oxygen species (mtROS) formation in human leukocytes. In vitro, mtROS-induced Nox activation was prevented by inhibitors of the mPTP, protein kinase C, tyrosine kin…