Urocortin 1 administration from onset of rapid left ventricular pacing represses progression to overt heart failure

Transcriptional Regulation, Signaling Pathways, and Subcellular Localization of Corticotropin-Releasing Factor Receptors in the Central Nervous System

Corticotropin-releasing factor (CRF) receptors CRF-R1 and CRF-R2 are differentially distributed in body tissues, and although they respond differentially to stimuli due to their association with different signaling pathways, both receptors have a fundamental role in the response and adaptation to stressful stimuli. Here, we summarize the reported data on different forms of CRF-R1 and CRF-R2 regulation as well as on their subcellular localization. Although the presence of R1 has been described at pre- and postsynaptic sites, R2 is mainly associated with postsynaptic densities. Different studies have provided valuable information on how these receptors regulate responses at a central level, elucidating different and sometimes synergistic roles in response to stress, but despite their high sequence identity, both receptors have been described to be differentially regulated both by their ligands and by transcriptional factors. To date, and from the point of view of their promoter sequences, it has not yet been reported how the different consensus sites identified in silico could be modulating the transcriptional regulation and expression of the receptors under different conditions, which strongly limits the full understanding of their differential functions, providing a wide field to increase and expand the study of the regulation and role of CRF receptors in the CRF system. SIGNIFICANCE STATEMENT: A large number of physiological functions related to the organization of the stress response in different body tissues are associated with the corticotropin-releasing factor system. This system also plays a relevant role in depression and anxiety disorders, as well as being a direct connection between stress and addiction. A better understanding of how the receptors of this system are regulated would help to expand the understanding of how these receptors respond differently to both drugs and stressful stimuli.

Acute Decompensated Heart Failure and the Kidney: Physiological, Histological and Transcriptomic Responses to Development and Recovery

BACKGROUND Acute decompensated heart failure (ADHF) is associated with deterioration in renal function-an important risk factor for poor outcomes. Whether ADHF results in permanent kidney damage/dysfunction is unknown. METHODS AND RESULTS We investigated for the first time the renal responses to the development of, and recovery from, ADHF using an ovine model. ADHF development induced pronounced hemodynamic changes, neurohormonal activation, and decline in renal function, including decreased urine, sodium and urea excretion, and creatinine clearance. Following ADHF recovery (25 days), creatinine clearance reductions persisted. Kidney biopsies taken during ADHF and following recovery showed widespread mesangial cell prominence, early mild acute tubular injury, and medullary/interstitial fibrosis. Renal transcriptomes identified altered expression of 270 genes following ADHF development and 631 genes following recovery. A total of 47 genes remained altered post-recovery. Pathway analysis suggested gene expression changes, driven by a network of inflammatory cytokines centered on IL-1β (interleukin 1β), lead to repression of reno-protective eNOS (endothelial nitric oxide synthase) signaling during ADHF development, and following recovery, activation of glomerulosclerosis and reno-protective pathways and repression of proinflammatory/fibrotic pathways. A total of 31 dysregulated genes encoding proteins detectable in urine, serum, and plasma identified potential candidate markers for kidney repair (including CNGA3 [cyclic nucleotide gated channel subunit alpha 3] and OIT3 [oncoprotein induced transcript 3]) or long-term renal impairment in ADHF (including ACTG2 [actin gamma 2, smooth muscle] and ANGPTL4 [angiopoietin like 4]). CONCLUSIONS In an ovine model, we provide the first direct evidence that an episode of ADHF leads to an immediate decline in kidney function that failed to fully resolve after ≈4 weeks and is associated with persistent functional/structural kidney injury. We identified molecular pathways underlying kidney injury and repair in ADHF and highlighted 31 novel candidate biomarkers for acute kidney injury in this setting.

Large Animal Models of Heart Failure: Reduced vs. Preserved Ejection Fraction

Heart failure (HF) is the final common end point of multiple metabolic and cardiovascular diseases and imposes a significant health care burden worldwide. Despite significant improvements in clinical management and outcomes, morbidity and mortality remain high and there remains an indisputable need for improved treatment options. The pathophysiology of HF is complex and covers a spectrum of clinical presentations from HF with reduced ejection fraction (HFrEF) (≤40% EF) through to HF with preserved EF (HFpEF), with HFpEF patients demonstrating a reduced ability of the heart to relax despite an EF maintained above 50%. Prior to the last decade, the majority of clinical trials and animal models addressed HFrEF. Despite growing efforts recently to understand underlying mechanisms of HFpEF and find effective therapies for its treatment, clinical trials in patients with HFpEF have failed to demonstrate improvements in mortality. A significant obstacle to therapeutic innovation in HFpEF is the absence of preclinical models including large animal models which, unlike rodents, permit detailed instrumentation and extensive imaging and sampling protocols. Although several large animal models of HFpEF have been reported, none fulfil all the features present in human disease and few demonstrate progression to frank decompensated HF. This review summarizes well-established models of HFrEF in pigs, dogs and sheep and discusses attempts to date to model HFpEF in these species.

MicroRNA and Heart Failure

Heart failure (HF) imposes significant economic and public health burdens upon modern society. It is known that disturbances in neurohormonal status play an important role in the pathogenesis of HF. Therapeutics that antagonize selected neurohormonal pathways, specifically the renin-angiotensin-aldosterone and sympathetic nervous systems, have significantly improved patient outcomes in HF. Nevertheless, mortality remains high with about 50% of HF patients dying within five years of diagnosis thus mandating ongoing efforts to improve HF management. The discovery of short noncoding microRNAs (miRNAs) and our increasing understanding of their functions, has presented potential therapeutic applications in complex diseases, including HF. Results from several genome-wide miRNA studies have identified miRNAs differentially expressed in HF cohorts suggesting their possible involvement in the pathogenesis of HF and their potential as both biomarkers and as therapeutic targets. Unravelling the functional relevance of miRNAs within pathogenic pathways is a major challenge in cardiovascular research. In this article, we provide an overview of the role of miRNAs in the cardiovascular system. We highlight several HF-related miRNAs reported from selected cohorts and review their putative roles in neurohormonal signaling.

Vasoprotective effects of urocortin 1 against atherosclerosis in vitro and in vivo

AIM

Atherosclerosis is the complex lesion that consists of endothelial inflammation, macrophage foam cell formation, vascular smooth muscle cell (VSMC) migration and proliferation, and extracellular matrix production. Human urocortin 1 (Ucn1), a 40-amino acid peptide member of the corticotrophin-releasing factor/urotensin I family, has potent cardiovascular protective effects. This peptide induces potent and long-lasting hypotension and coronary vasodilation. However, the relationship of Ucn1 with atherosclerosis remains unclear. The present study was performed to clarify the effects of Ucn1 on atherosclerosis.

METHODS

We assessed the effects of Ucn1 on the inflammatory response and proliferation of human endothelial cells (ECs), human macrophage foam cell formation, migration and proliferation of human VSMCs, extracellular matrix expression in VSMCs, and the development of atherosclerosis in apolipoprotein E-deficient (Apoe-/-) mice.

RESULTS

Ucn1 significantly suppressed cell proliferation without inducing apoptosis, and lipopolysaccharide-induced up-regulation of monocyte chemoattractant protein-1 and intercellular adhesion molecule-1 in human ECs. Ucn1 significantly reduced oxidized low-density lipoprotein-induced foam cell formation with a significant down-regulation of CD36 and acyl-CoA:cholesterol acyltransferase 1 in human monocyte-derived macrophages. Ucn1 significantly suppressed the migration and proliferation of human VSMCs and increased the activities of matrix metalloproteinase-2 (MMP2) and MMP9 in human VSMCs. Intraperitoneal injection of Ucn1 into Apoe-/- mice for 4 weeks significantly retarded the development of aortic atherosclerotic lesions.

CONCLUSIONS

This study provided the first evidence that Ucn1 prevents the development of atherosclerosis by suppressing EC inflammatory response and proliferation, macrophage foam cell formation, and VSMC migration and proliferation. Thus, Ucn1 could serve as a novel therapeutic target for atherosclerotic cardiovascular diseases.

Hemodynamic, Hormonal, and Renal Effects of (Pro)Renin Receptor Blockade in Experimental Heart Failure

Background—

The (pro)renin receptor (P)RR is implicated in blood pressure regulation and the pathophysiology of heart failure (HF). The effects of (P)RR blockade in HF have not been previously investigated.

Methods and Results—

Eight sheep received on 2 separate days a vehicle control and incremental intravenous boluses of a (P)RR antagonist, ovine handle region peptide (HRP) (1, 5, and 25 mg at 90-minute intervals), both before (normal) and after induction of HF by rapid left ventricular pacing. In normal sheep, HRP reduced heart rate ( P <0.001) and hematocrit ( P =0.019) compared with time-matched control data, without significantly affecting any other hemodynamic, hormonal, or renal variables. In sheep with HF, HRP treatment induced progressive falls in mean arterial pressure ( P <0.001) in association with decreases in left atrial pressure ( P <0.001), peripheral resistance ( P =0.014), and hematocrit ( P <0.001). Cardiac contractility tended to decline ( P =0.096), whereas cardiac output was unaltered. HRP administration produced a dose-dependent decrease in plasma renin activity ( P =0.004), with similar trends observed for plasma angiotensin II and aldosterone ( P =0.093 and P =0.088, respectively). Circulating natriuretic peptides, endothelin-1, and catecholamine levels were unchanged. HRP also induced a reduction in plasma sodium concentrations relative to control ( P =0.024), a natriuresis ( P =0.046), and a tendency for creatinine excretion and clearance to improve.

Conclusions—

(P)RR antagonism in experimental HF resulted in cardiovascular and renal benefits in association with inhibition of the renin-angiotensin-aldosterone system. These findings suggest that (P)RR contributes to pressure/volume regulation in HF and identifies the receptor as a potential therapeutic target in this disease.

Urocortin-dependent effects on adrenal morphology, growth, and expression of steroidogenic enzymes in vivo

Urocortin (UCN) 1, 2, and 3 are members of the corticotropin-releasing factor (CRF) family that display varying affinities to the CRF receptor 1 (CRFR1 (CRHR1)) and 2 (CRFR2 (CRHR2)). UCNs represent important modulators of stress responses and are involved in the control of anxiety and related disorders. In addition to the CNS, UCNs and CRFRs are highly expressed in several tissues including the adrenal gland, indicating the presence of UCN-dependent regulatory mechanisms in these peripheral organ systems. Using knockout (KO) mouse models lacking single or multiple Ucn genes, we examined the potential role of the three different Ucns on morphology and function of the adrenal gland. Adrenal morphology was investigated, organ size, cell size, and number were quantified, and growth kinetics were studied by proliferative cell nuclear antigen staining and Ccnd1 expression analysis. Furthermore, mRNA expression of enzymes involved in steroidogenesis and catecholamine synthesis was quantified by real-time PCR. Following this approach, Ucn2, Ucn1/Ucn2 dKO and Ucn1/Ucn2/Ucn3 tKO animals showed a significant cellular hypotrophy of the adrenal cortex and an increase in Ccnd1 expression, whereas in all other genotypes, no changes were observable in comparison to age-matched controls. For steroidogenesis, Ucn2/Ucn3 dKO animals displayed the most pronounced changes, with significant increases in all investigated enzymes, providing indirect evidence for increased stress behavior. Taken together, these data suggest that mainly Ucn2 and Ucn3 could be involved in adrenal stress response regulation while Ucn2 additionally appears to play a role in morphology and growth of the adrenal gland.

Haemodynamic, endocrine and renal actions of adrenomedullin 5 in an ovine model of heart failure

AM5 (adrenomedullin 5), a newly described member of the CGRP (calcitonin gene-related peptide) family, is reported to play a role in normal cardiovascular physiology. The effects of AM5 in HF (heart failure), however, have not been investigated. In the present study, we intravenously infused two incremental doses of AM5 (10 and 100 ng/min per kg of body weight each for 90 min) into eight sheep with pacing-induced HF. Compared with time-matched vehicle control infusions, AM5 produced progressive and dose-dependent increases in left ventricular dP/dt(max) [LD (low dose), +56 mmHg/s and HD (high dose), +152 mmHg/s] and cardiac output (+0.83 l/min and +1.81 l/min), together with decrements in calculated total peripheral resistance (−9.4 mmHg/min per litre and −14.7 mmHg/min per litre), mean arterial pressure (−2.8 mmHg and −8.4 mmHg) and LAP (left atrial pressure; −2.6 mmHg and −5.6 mmHg) (all P<0.001). HD AM5 significantly raised PRA (plasma renin activity) (3.5-fold increment, P<0.001), whereas plasma aldosterone levels were unchanged over the intra-infusion period and actually fell in the post-infusion period (70% decrement, P<0.01), resulting in a marked decrease in the aldosterone/PRA ratio (P<0.01). Despite falls in LAP, plasma atrial natriuretic peptide and B-type natriuretic peptide concentrations were maintained relative to controls. AM5 infusion also induced significant increases in urine volume (HD 2-fold increment, P<0.05) and urine sodium (2.7-fold increment, P<0.01), potassium (1.7-fold increment, P<0.05) and creatinine (1.4-fold increment, P<0.05) excretion and creatinine clearance (60% increment, P<0.05). In conclusion, AM5 has significant haemodynamic, endocrine and renal actions in experimental HF likely to be protective and compensatory in this setting. These results suggest that AM5 may have potential as a therapeutic agent in human HF.

Distribution of urocortins and corticotropin-releasing factor receptors in the cardiovascular system

Urocortins are human homologues of urotensin I, a fish corticotropin-releasing-factor- (CRF-) like peptide secreted from the urophysis. There are three urocortins: urocortin 1, urocortin 2, and urocortin 3 in mammals. We have shown that urocortin 1 and urocortin 3 are endogenously synthesized in the myocardial cells of human heart and may act on CRF type 2 receptor (CRFR2) expressed in the heart. Expression levels of urocortin 1 in the heart and plasma urocortin 1 levels are elevated in patients with heart failure. Recent studies have shown that urocortins have various biological actions in the cardiovascular system, such as a vasodilator action, a positive inotropic action, a cardioprotective action against ischemia/reperfusion injury, and suppressive actions against the renin angiotensin system and the sympathetic nervous system. Urocortins and CRFR2 may therefore be a potential therapeutic target for cardiovascular diseases, such as congestive heart failure, hypertension, and myocardial infarction.

Clinical perspectives of urocortin and related agents for the treatment of cardiovascular disease

The effects of corticotropin-releasing hormone, also known as corticotropin-releasing factor (CRF), on the cardiovascular system have been intensively researched since its discovery. Moreover, the actions of urocortin (Ucn) I on the cardiovascular system have also been intensively scrutinized following the cloning and identification of its receptor, CRF receptor type 2 (CRFR2), in peripheral tissues including the heart. Given the cardioprotective actions of CRFR2 ligands, the clinical potential of not only Ucn I but also Ucn II and III, which were later identified as more specific ligands for CRFR2, has received considerable attention from researchers. In addition, recent work has indicated that CRF type 1 receptor may be also involved in cardioprotection against ischemic/reperfusion injury. Here we provide a historical overview of research on Ucn I and related agents, their effects on the cardiovascular system, and the clinical potential of the use of such agents to treat cardiovascular diseases.

Relevance of urocortins to cardiovascular disease

Acquired cardiovascular diseases such as coronary heart disease, peripheral artery disease and related vascular problems contribute to more than one-third of worldwide morbidity and mortality. In many instances, particularly in the under developed world, cardiovascular diseases are diagnosed at a late stage limiting the scope for improving outcomes. A range of therapies already exist for established cardiovascular disease, although there is significant interest in further understanding disease pathogenesis in order to improve diagnosis and achieve primary and secondary therapeutic goals. The urocortins are a group of recently defined peptide members of the corticotrophin-releasing factor family. Previous pre-clinical work and human association studies suggest that urocortins have potential to exert some beneficial and other detrimental effects on the heart and major blood vessels. More current evidence however favours beneficial effects of urocortins, for example these peptides have been shown to inhibit production of reactive oxygen species and vascular cell apoptosis, and thus may have potential to antagonise the progression of cardiovascular disease. This review summarises published data on the potential role of urocortins in cardiovascular disease.

Prolonged urocortin 2 administration in experimental heart failure: sustained hemodynamic, endocrine, and renal effects

Although acute administration of urocortin 2 has beneficial actions in heart failure, the integrated hemodynamic, hormonal, and renal effects of sustained urocortin 2 treatment in this disease have not been investigated. In the current study, we administered a 4-day infusion of a vehicle control (0.9% saline; n=6) or urocortin 2 (0.75 μg/kg per hour; n=6) to sheep with pacing-induced heart failure. Compared with time-matched controls, infusion of urocortin 2 produced rapid (30-minute) and persistent (4-day) improvements in cardiac contractility (day 4: control 905±73 versus urocortin 2 1424±158 mm Hg/s; P<0.001) and output (2.6±0.1 versus 3.8±0.3 L/min; P<0.001), together with reductions in left atrial pressure (28±1 versus 12±1 mm Hg; P<0.001) and peripheral resistance (30±2 versus 20±2 mm Hg/L per min; P<0.001). In contrast, urocortin 2-induced falls in mean arterial pressure were not established until the second day (day 4: 74±2 versus 72±2 mm Hg; P<0.05). Prolonged urocortin 2 administration was associated with sustained (days 0 to 4) declines in plasma renin activity (day 4: 1.33±0.27 versus 0.73±0.20 nmol/L per hour; P<0.001), aldosterone (970±383 versus 396±96 pmol/L; P<0.05), vasopressin (2.4±0.8 versus 1.3±0.1 pmol/L; P<0.05), endothelin 1 (7.2±0.7 versus 4.5±0.4 pmol/L; P<0.01), and atrial (269±27 versus 150±19 pmol/L; P<0.001) and B-type (65±9 versus 29±6 pmol/L; P<0.001) natriuretic peptides, as well as an acute transient rise in plasma cortisol (day 1: P<0.001). Chronic urocortin 2 also persistently augmented urinary sodium (day 4: 4-fold increase; P<0.001) and creatinine (1.4-fold; P<0.001) excretion and creatinine clearance (1.5-fold; P<0.01) compared with control. Food consumption was temporarily suppressed (P<0.05). In conclusion, 4-day urocortin 2 administration induces sustained improvements in hemodynamics and renal function, in association with inhibition of multiple vasoconstrictor/volume-retaining systems. These findings support the therapeutic potential for urocortin 2 in heart failure.

New targets of urocortin-mediated cardioprotection

The urocortin (UCN) hormones UCN1 and UCN2 have been shown previously to confer significant protection against myocardial ischaemia/reperfusion (I/R) injury; however, the molecular mechanisms underlying their action are poorly understood. To further define the transcriptional effect of UCNs that underpins their cardioprotective activity, a microarray analysis was carried out using an in vivo rat coronary occlusion model of I/R injury. Infusion of UCN1 or UCN2 before the onset of reperfusion resulted in the differential regulation of 66 and 141 genes respectively, the majority of which have not been described previously. Functional analysis demonstrated that UCN-regulated genes are involved in a wide range of biological responses, including cell death (e.g. X-linked inhibitor of apoptosis protein), oxidative stress (e.g. nuclear factor erythroid derived 2-related factor 1/nuclear factor erythroid derived 2-like 1) and metabolism (e.g. Prkaa2/AMPK). In addition, both UCN1 and UCN2 were found to modulate the expression of a host of genes involved in G-protein-coupled receptor (GPCR) signalling including Rac2, Gnb1, Dab2ip (AIP1), Ralgds, Rnd3, Rap1a and PKA, thereby revealing previously unrecognised signalling intermediates downstream of CRH receptors. Moreover, several of these GPCR-related genes have been shown previously to be involved in mitogen-activated protein kinase (MAPK) activation, suggesting a link between CRH receptors and induction of MAPKs. In addition, we have shown that both UCN1 and UCN2 significantly reduce free radical damage following myocardial infarction, and comparison of the UCN gene signatures with that of the anti-oxidant tempol revealed a significant overlap. These data uncover novel gene expression changes induced by UCNs, which will serve as a platform to further understand their mechanism of action in normal physiology and cardioprotection.

Novel biomarkers in heart failure: an overview

Heart failure is a complex systemic syndrome resulting from significant impairment of cardiac function. A vast array of biological pathways is now known to be involved in heart failure, including deleterious pathways promoting its development and progression, as well as compensatory cardioprotective pathways. Some of the components of these pathways are now recognized as biomarkers of this condition, and can aid diagnosis, prognostication and guide management. As the understanding of the pathophysiology of heart failure progresses, further candidate biomarkers are being identified. This article reviews the literature regarding the more recently identified biomarkers and outlines areas requiring further study.

Novel neurohormonal insights with therapeutic potential in chronic heart failure

Despite considerable therapeutic advances over recent years, chronic heart failure remains associated with significant morbidity and mortality. Further improvements in the treatment of this syndrome are therefore needed and this will require advances in the understanding of its underlying pathophysiology. This article reviews the literature regarding recently identified neurohormonal pathways that are declaring themselves as potential therapeutic targets in chronic heart failure.

Urocortin 2 inhibits furosemide-induced activation of renin and enhances renal function and diuretic responsiveness in experimental heart failure

BACKGROUND

Urocortin 2 (Ucn2), a novel peptide with therapeutic potential in heart failure, and diuretics have opposing effects on renal function and the renin-angiotensin-aldosterone system. Because any prospective new treatment is likely to be used in conjunction with standard diuretic therapy, it is necessary to investigate the combined effects of these agents.

METHODS AND RESULTS

Ucn2 and furosemide were administered for 3 hours, both singly and combined, in 7 sheep with pacing-induced heart failure. Compared with time-matched controls, separate Ucn2 and furosemide administration significantly increased urine output (furosemide>Ucn2), urine sodium (furosemide>Ucn2), potassium (furosemide>Ucn2), and creatinine excretion (Ucn2>furosemide) and creatinine clearance (Ucn2>furosemide). Compared with furosemide treatment alone, Ucn2+furosemide produced a further diuresis (P<0.05), natriuresis (P<0.05), and a sustained increase in creatinine excretion (P<0.05) and clearance (P<0.05), without additional potassium elimination. All active treatments reduced mean arterial pressure (Ucn2+furosemide=furosemide>Ucn2), left atrial pressure (Ucn2+furosemide>Ucn2>furosemide), and peripheral resistance (Ucn2+furosemide=Ucn2>furosemide), whereas only Ucn2, singly and in combination with furosemide, increased cardiac output and dP/dt(max). In contrast to the increase in plasma renin activity elicited by furosemide alone, Ucn2 and Ucn2+furosemide markedly reduced plasma renin activity. All active treatments decreased plasma aldosterone (Ucn2+furosemide=Ucn2>furosemide), whereas only Ucn2 and Ucn2+furosemide reduced vasopressin and natriuretic peptide concentrations.

CONCLUSIONS

Ucn2 cotreatment with furosemide enhanced hemodynamic and renal function and diuretic responsiveness (without additional potassium depletion) in experimental heart failure. Furthermore, Ucn2 reversed furosemide-induced increases in plasma renin activity and induced greater decreases in plasma aldosterone and vasopressin. These data indicate that adjunct Ucn2 therapy with diuretics in heart failure is beneficial.

Hemodynamic, hormonal, and renal actions of adrenomedullin 2 in experimental heart failure

BACKGROUND

Adrenomedullin 2 (AM2) is a novel member of the calcitonin gene-related peptide family that is thought to play a regulatory role in circulatory homeostasis under normal physiological conditions. The effects of AM2 in heart failure have not been investigated previously.

METHODS AND RESULTS

Two incremental doses of human AM2 (10 and 100 ng[kg.min] for 90 minutes each) were given by intravenous infusion to 8 sheep with pacing-induced heart failure. Compared with time-matched control infusions, AM2 produced dose-dependent increases in left ventricular dP/dt(max) (control 1168+/-138 mm Hg/s versus AM2 high-dose 1402+/-130 mm Hg/s; P<0.01) and cardiac output (2.09+/-0.66 L/min versus 3.81+/-0.30 L/min; P<0.001) and reductions in calculated total peripheral resistance (40+/-6 mm Hg(L.min) versus 21+/-4 mm Hg(L.min); P<0.001), mean arterial pressure (74.4+/-2.4 mm Hg versus 66.2+/-2.5 mm Hg; P<0.001), and left atrial pressure (23.3+/-1.0 mm Hg versus 18.8+/-1.3 mm Hg; P<0.001). AM2 administration also induced significant elevations in plasma cAMP (P<0.01) in association with rises in atrial (P<0.05) and brain (P<0.01) natriuretic peptides and plasma renin activity (P<0.01). Despite the increase in renin activity, plasma aldosterone levels were not significantly altered, whereas the aldosterone/plasma renin activity ratio was reduced (P=0.08). Plasma vasopressin, endothelin-1, and catecholamines levels were also unchanged by AM2. Renal effects of AM2 included increased excretion of sodium (P<0.05), cAMP (P<0.01), and creatinine (P<0.05), with augmented creatinine clearance (P<0.05), and a trend for urine output to rise (P=0.068).

CONCLUSIONS

These results indicate that AM2 administration has favorable effects on cardiovascular, endocrine, and renal indexes in heart failure and identify the peptide as a potential therapeutic target in this disease.