The results were independent of the etiology of the heart failure and suggest that increased levels of atrial AT1R mRNA may occur in response to elevated atrial pressures in heart failure.
In human ventricles (n=13), message levels of atrial natriuretic peptide and AT(1) receptor were inversely correlated, which suggests a decrease in AT(1) receptor expression with progressive heart failure.
In conclusion, the diminished angiotensin II vasoconstriction with age in heart failure patients is most likely due to a lower density of AT(1) receptors and may result from a longer period of exposure to heart failure in older patients.
Here we demonstrate that a polymorphism in the AT1R gene (A1166C), linked to increased receptor activity, is associated with elevated levels of oxidative stress markers in heart failure patients but not in healthy controls.
Blockade of angiotensin II type 1 receptor (AT1) signaling attenuates heart failure following myocardial infarction (MI), perhaps through reduction of fibrosis in the noninfarcted myocardium.
The results of this proof-of concept study provide the first evidence that the AGTR1A1166C polymorphism could influence the response to candesartan in patients with heart failure who are receiving ACE inhibitors.
We genotyped 134 patients with HF and reduced systolic function for the AT1RA1166C genotype using polymerase chain reaction and restriction fragment length polymorphism.
Heart failure-related genes, such as brain natriuretic peptide, connective tissue growth factor and osteopontin; calcium signaling-related genes, such as ryanodine receptor 2, sarcoendoplasmic reticulum Ca(2+)-ATPase 2A2 and adenylate cyclase 7; renin-angiotensin system-related genes, such as angiotensinogen, angiotensin II receptor, type 1 and type 2; and mitochondria-related genes, such as peroxisome proliferator-activated receptor-gamma co-activator-1alpha, cytochrome c and transcription factor A mitochondrial, were significantly changed at the apical ventricle rather than at the basal ventricle.
Because the increase in AT(1)R expression and transcription factor activation can be blocked by the AT(1)R antagonist losartan, a positive feedback mechanism of AT(1)R expression in CHF is suggested.
The protective effects of telmisartan and losartan in ADR-induced heart failure may be partially due to regulation of circulating Ang-(1-7) and myocardial AT(1)R expression.
An upregulation in angiotensin II type 1 receptor expression was detected in medullary nuclei in WT CHF mice, which was significantly attenuated in SA mice with CHF.
Our study suggests that the AT1R-1166CC genotype is associated with increased ICD therapies in patients with chronic HF, and the level of circulating miR-155 may be a potential marker for arrhythmic risk.
These data suggest that the serum levels of ghrelin are significantly positively correlated with Ang II in CHF patients and that ghrelin can inhibit Ang II-induced cardiomyocyte apoptosis by down-regulating AT1R, thereby playing a role in preventing HF.
In addition, the pharmacology of a new class of compounds which display both AT1-receptor blocking properties combined with inhibition of neprilysin, the vasopeptidase enzyme degradating natriuretic peptide (ARNi), will be reviewed, alongside with their impact in the pathophysiology of chronic HF.
Intracellular Ang-II and nuclear AT1R protein levels were significantly increased in a heart failure model in which atrial fibrosis underlies atrial fibrillation.
Sacubitril/valsartan (LCZ-696) is a combined neprilysin inhibitor and angiotensin AT1 receptor blocker approved in recent years for the treatment of chronic heart failure with reduced ejection fraction.