Search results for "Angiotensin I"
showing 10 items of 181 documents
Plasma noradrenaline and the pressor action of exogenous noradrenaline in normotensive subjects and patients with essential hypertension.
1978
1. An inverse relationship was found between plasma noradrenaline and reactivity to exogenous noradrenaline in normotensive subjects. 2. The relationship between plasma noradrenaline and reactivity was disturbed in age-matched patients with essential hypertension. 3. A multiple-regression analysis showed a highly significant correlation between adrenergic activity and reactivity to noradrenaline and the mean arterial blood pressure level (r = 0·91). The results suggest that adrenergic activity and pressor response to noradrenaline combined are important determinants of arterial blood pressure. 4. An inverse relationship could also be demonstrated between plasma renin activity and reactivity…
Does the renin-angiotensin system also regulate intra-ocular pressure?
2009
The renin-angiotensin-aldosterone system is known to play an essential role in controlling sodium balance and body fluid volumes, and thus blood pressure. In addition to the circulating system which regulates urgent cardiovascular responses, a tissue-localized renin-angiotensin system (RAS) regulates long-term changes in various organs. Many recognized RAS components have also been identified in the human eye. The highly vasoconstrictive angiotensin II (Ang II) is considered the key peptide in the circulatory RAS. However, the ultimate effect of RAS activation at tissue level is more complex, being based not only on the biological activity of Ang II but also on the activities of other produ…
Nitric Oxide Opposes Myogenic Pressure Responses Predominantly in Large Arterioles In Vivo
1998
Abstract —A myogenic vasoconstriction may amplify the effects of circulating vasoconstrictors. In cremaster arterioles, the contribution of a myogenic component to the constriction on intravenous infusion of norepinephrine (NE) or angiotensin II (Ang II) was studied. Second, the role of endothelium-derived nitric oxide (NO) in the control of these myogenic constrictions and its site of action in the resistance vascular bed was investigated. In 30 anesthetized (pentobarbital) hamsters, the cremaster was prepared for intravital microscopy, and a pneumatic vessel occluder was placed around the aorta to vary blood pressure in the hindquarter of the animal. Intravenous infusion of NE (0.5 nmol/…
One-year renal and cardiac effects of bisoprolol versus losartan in recently diagnosed hypertensive patients: a randomized, double-blind study.
2009
BACKGROUND AND OBJECTIVES: Hypertension is a significant cause of chronic renal injury and its effective treatment is capable of reducing the rate of renal failure. beta-Adrenoceptor antagonists (beta-blockers) have been reported to induce a deterioration in renal function, while several data have indicated a renoprotective effect of treatment with the angiotensin II type 1 receptor antagonist losartan. Previous studies of the interaction between the selective beta(1)-blocker bisoprolol and kidney function were performed only for short- and medium-term periods. The aim of this study was to compare the antihypertensive efficacy and renal and cardiac haemodynamic effects of bisoprolol with th…
Nebivolol inhibits superoxide formation by NADPH oxidase and endothelial dysfunction in angiotensin II-treated rats.
2006
Nebivolol is a β 1 -receptor antagonist with vasodilator and antioxidant properties. Because the vascular NADPH oxidase is an important superoxide source, we studied the effect of nebivolol on endothelial function and NADPH oxidase activity and expression in the well-characterized model of angiotensin II–induced hypertension. Angiotensin II infusion (1 mg/kg per day for 7 days) caused endothelial dysfunction in male Wistar rats and increased vascular superoxide as detected by lucigenin-derived chemiluminescence, as well as dihydroethidine staining. Vascular NADPH oxidase activity, as well as expression at the mRNA and protein level, were markedly upregulated, as well as NOS III uncoupled, …
Platelet-localized FXI promotes a vascular coagulation-inflammatory circuit in arterial hypertension
2017
Multicellular interactions of platelets, leukocytes, and the blood vessel wall support coagulation and precipitate arterial and venous thrombosis. High levels of angiotensin II cause arterial hypertension by a complex vascular inflammatory pathway that requires leukocyte recruitment and reactive oxygen species production and is followed by vascular dysfunction. We delineate a previously undescribed, proinflammatory coagulation-vascular circuit that is a major regulator of vascular tone, blood pressure, and endothelial function. In mice with angiotensin II-induced hypertension, tissue factor was up-regulated, as was thrombin-dependent endothelial cell vascular cellular adhesion molecule 1 ex…
The effect duration of candesartan cilexetil once daily, in comparison with enalapril once daily, in patients with mild to moderate hypertension.
2001
To determine the antihypertensive efficacy, effect duration and safety of the angiotensin II type 1 receptor blocker candesartan cilexetil and the angiotensin converting enzyme inhibitor enalapril once daily in patients with mild to moderate hypertension.A multicenter, randomised, double-blind parallel group study was performed in Finland, France, the Netherlands, Spain and Sweden. Three-hundred-and-ninety-five men and women in the age range 20-80 years with primary hypertension were randomised to an 8-week double-blind treatment period with either candesartan cilexetil 8-16 mg or enalapril 10-20 mg once daily, with forced dose titration after 4 weeks. Non-invasive ambulatory blood pressure…
Angiotensin II and leukocyte trafficking: New insights for an old vascular mediator. Role of redox-signaling pathways.
2019
Abstract Inflammation and activation of the immune system are key molecular and cellular events in the pathogenesis of cardiovascular diseases, including atherosclerosis, hypertension-induced target-organ damage, and abdominal aortic aneurysm. Angiotensin II (Ang-II) is the main effector peptide hormone of the renin-angiotensin system. Beyond its role as a potent vasoconstrictor and regulator of blood pressure and fluid homeostasis, Ang-II is intimately involved in the development of vascular lesions in cardiovascular diseases through the activation of different immune cells. The migration of leukocytes from circulation to the arterial subendothelial space is a crucial immune response in le…
Endothelial Bmx tyrosine kinase activity is essential for myocardial hypertrophy and remodeling
2015
Cardiac hypertrophy accompanies many forms of heart disease, including ischemic disease, hypertension, heart failure, and valvular disease, and it is a strong predictor of increased cardiovascular morbidity and mortality. Deletion of bone marrow kinase in chromosome X (Bmx), an arterial nonreceptor tyrosine kinase, has been shown to inhibit cardiac hypertrophy in mice. This finding raised the possibility of therapeutic use of Bmx tyrosine kinase inhibitors, which we have addressed here by analyzing cardiac hypertrophy in gene-targeted mice deficient in Bmx tyrosine kinase activity. We found that angiotensin II (Ang II)-induced cardiac hypertrophy is significantly reduced in mice deficient i…
Efficacy in angiotensin receptor blockade: a comparative review of data with olmesartan
2009
A range of angiotensin II receptor blockers (ARB) is available, and analyses suggest there are differences between agents in terms of antihypertensive efficacy and 24-hour blood pressure control.This review assesses the data comparing olmesartan with other ARBs in terms of blood pressure reductions, goal achievement, 24-hour control and speed of onset. Olmesartan seems to have a more favourable efficacy profile relative to standard doses of the ARBs used in comparative studies; results consistent with the high degree of blockade of the angiotensin II type 1 receptor for olmesartan.Taken together, there might be differences between ARBs regarding their blood pressure lowering efficacy, and …