Search results for "Angiotensin"
showing 10 items of 396 documents
Drug induced variations of the renin-angiotensin-aldosterone system in rats. II. Antihypertensives
1977
Summary Groups of male rats were treated with antihypertensive drugs (alpha-methyl-dopa, clonidine, propranolol, reserpine, diazoxide) which were administered under conditions causing the onset of high plasma renin activity (PRA) and high plasma and urine aldosterone levels, i.e. together with distilled water load (5% of body weight). Alpha-methyl-dopa and propranolol, which fail to significantly alter PRA and plasma aldosterone levels when administered without distilled water load, cause a marked decrease of plasma and urine aldosterone levels and of PRA when administered together with distilled water load, while diazoxide, and reserpine cause a marked increase of these values. Clonidine c…
AT1-receptor blockade with irbesartan improves peripheral but not coronary endothelial dysfunction in patients with stable coronary artery disease
2007
Activation of the renin-angiotensin-aldosterone system plays an important role in the pathogenesis of endothelial dysfunction and atherosclerosis. Studies evaluating the effect of AT1-receptor blockers on endothelial dysfunction in patients with coronary artery disease (CAD) revealed mixed results. Studies addressing the effects of AT1-receptor blockers on the coronary and peripheral function in the same study population, are still lacking. We therefore aimed to test the effects of long-term therapy with the AT1-receptor blocker irbesartan (IRB) on both, the coronary and peripheral endothelial function in patients with CAD. Seventy-two patients with CAD were randomly assigned to double-blin…
Effects of captopril on myocardial protection during cardioplegia
1993
Abstract The study aimed at checking effects exerted by captopril (C) on human myocardial ACE system as well as the role played by tissue ACE inhibition in reducing reperfusion damage. A human experimental model was used during cardioplegia due to aorto-coronary-by-pass (CABG). Fifty-four patients with coronary artery disease affecting 3 vessels having suffered from acute myocardial infarction anterior (AMI-ant), homogeneous as far as ejection fraction (35–55%), number of grafts (3), clamping time, age and sex, were randomised in a double blind experiment, and were given captopril or placebo (P). A total of 4 mg/l Captopril was mixed into the cardioplegic solution with blood according to th…
Captopril does not affect plasma endothelin-1 during thrombolysis and reperfusion.
1995
Studies showed that endothelin-1 (ET-1) was increased in the acute myocardial infarction (AMI). Experimental studies reported that captopril was able to reduce ET-1 secretion, and that ET-1 was increased during reperfusion. This study was aimed to verify if captopril was able to reduce plasma ET-1 during thrombolysis in AMI. Seventy-three patients, hospitalized for suspected AMI within 4 h from the onset of symptoms suitable for thrombolysis (1st episode), Killip class 1-2, were randomized (double blind) into two groups: group 1 (37 pts), 8 F/29 M, received captopril, 6.25 mg, orally 15 min before thrombolysis. Group 2: (36 pts) 8 F/28 M, received placebo before thrombolysis. All patients m…
The combination ace-inhibitors plus canreonate in patients with anterior myocardial infarction: safety and tolerability study.
2001
There is recent evidence that aldosterone (ALDO) exerts pro-fibrotic effects, acting via the mineral-corticoid receptors in cardiovascular tissues and partial aldosterone escape during ACE-inhibition treatment occurs.A double blind randomised study was performed to evaluate the feasibility, and tolerability of the administration of the 25 mg/day of canreonate plus captopril versus captopril alone in patients with anterior AMI unsuitable for thrombolysis and/or not receiving thrombolytic treatment, and unreperfused after thrombolysis. Fifty five patients hospitalised for anterior AMI,with a serum creatinine concentration2.0 mg/dl and a serum K concentration5.0 mmol per liter were randomised …
Novel antihypertensive hexa- and heptapeptides with ACE-inhibiting properties: From the in vitro ACE assay to the spontaneously hypertensive rat
2011
Bioactive ACE inhibiting peptides are gaining interest in hypertension treatment. We have designed and screened six synthetic heptapeptides (PACEI48 to PACEI53) based on two hexapeptide leads (PACEI32 and PACEI34) to improve ACE inhibitory properties and assess their antihypertensive effects. ACE activity was assayed in vitro and ex vivo. Selected peptides were administered to spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats. In vitro cytotoxicity was assessed with the MTT reduction test. The six heptapeptides at low micromolar concentration produced different degrees of in vitro inhibition of ACE activity using the synthetic substrate HHL or the natural subst…
CXCR2 blockade impairs angiotensin II-induced CC chemokine synthesis and mononuclear leukocyte infiltration.
2007
Objective—Angiotensin II (Ang-II) and mononuclear leukocytes are involved in atherosclerosis. This study reports the inhibition of Ang-II–induced mononuclear cell recruitment by CXCR2 antagonism and the mechanisms involved.Methods and Results—Ang-II (1 nmol/L, i.p. in rats) induced CXC and CC chemokines, followed by neutrophil and mononuclear cell recruitment. Administration of the CXCR2 antagonist, SB-517785-M, inhibited the infiltration of both neutrophils (98%) and mononuclear cells (60%). SB-517785-M had no effect on the increase in CXC chemokine levels but reduced MCP-1, RANTES, and MIP-1α release by 66%, 63%, and 80%, respectively. Intravital microscopy showed that pretreatment with S…
Angiotensin II contractile effects in mouse colon: role for pre- and post-junctional AT1A receptors
2013
Aim This study investigates whether a local renin–angiotensin system (RAS) exists in mouse colon and whether angiotensin II (Ang II) may play a role in the regulation of the contractile activity. Methods Isometric recordings were performed in vitro on the longitudinal muscle of mouse proximal and distal colon. Transcripts encoding for RAS components were investigated by RT-PCR. Results Ang II caused, in both preparations, a concentration-dependent contractile effect, antagonized by losartan, AT1 receptor antagonist, but not by PD123319, AT2 receptor antagonist. The combination of losartan plus PD123319 caused no change on the Ang II-induced contraction than losartan alone. Tetrodotoxin, neu…
Transmural distribution of biochemical markers of total protein and collagen synthesis, myocardial contraction speed and capillary density in the rat…
1988
The effect of angiotensin II-induced hypertension on selected biochemical parameters was studied in Sprague-Dawley rats. Angiotensin II infusion at rates of 41.7 micrograms h-1 kg-1 and 12.5 micrograms h-1 kg-1 for 2, 5, 10 and 15 days elevated the systolic blood pressure from 143 +/- 7 mmHg to 215-230 mmHg (P less than 0.001) and 185-195 mmHg (P less than 0.001), respectively. The left ventricular weight/body weight ratio increased 10-14% (P less than 0.05) and 23-32% (P less than 0.001) after 2-15 days in rats treated at the lower and higher infusion rates, respectively. Prolyl 4-hydroxylase (PH) activity, a marker of collagen synthesis, was evenly distributed in the left ventricle. PH ac…
Drug-induced variations of the renin-angiotensin-aldosterone system in rats. I. Diuretics.
1977
Summary Groups of 10 rats were treated with diuretics (furosemide, hydrochlorotiazide, spironolactone, triamterene) under conditions of high or low plasma renin activity (PRA) brought about by administering distilled water or saline load, respectively. PRA, plasma aldosterone levels, urine aldosterone concentration as well as diuresis and Na+ and K+ excretion were