Renal and cardiac neuropeptide Y and NPY receptors in a rat model of congestive heart failure

Elevated serum neuropeptide Y levels are associated with carotid plaque formation in Chinese adults: a cross-sectional study

BACKGROUND

Carotid plaque (CP) formation is an important consequence of atherosclerosis and leads to significant complications. Levels of neuropeptide Y (NPY), which is a sympathetic neurotransmitter, are elevated in cardiovascular diseases. It also has important roles in inflammatory conditions. This study aimed to explore the relationship between serum NPY and CP and to study further the influence of NPY and inflammatory factors on CP.

METHODS

This cross-sectional study was conducted among 300 adults who underwent a health examination at the Second Affiliated Hospital of Fujian Medical University in Fujian Province, of whom 177 were finally enrolled. The participants were divided into the CP (n = 120) and non-CP (NCP) or control (n = 57) groups according to the results of carotid artery color Doppler ultrasound. The CP group was further classified into stable plaque (SP, n = 80) and vulnerable plaque (VP, n = 40) groups based on plaque characteristics. Serum NPY and pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) levels were examined. Univariate and correlation analyses were used to evaluate the correlation between serum NPY levels, pro-inflammatory cytokines, and the CP phenotype.

RESULTS

The serum NPY and TNF-α levels of patients in the CP group were significantly higher than those in individuals from the NCP group [ (177.30 ± 43.29) pg.mL- 1 vs. (121.53 ± 40.16)pg.mL- 1, P < 0.001; (41.94 ± 14.19) pg.mL- 1 vs.(33.54 ± 13.37)pg.mL- 1, P = 0.003]. The serum NPY levels of the patients in the VP group were significantly higher than those in patients from the SP group [(191.67 ± 39.87)ng.L- 1 vs.(170.12 ± 43.37)ng.L- 1, P = 0.01, P < 0.05]. Serum TNF-α and NPY levels were positively correlated among patients from the CP group (r = 0.184, P = 0.044). The binary logistic regression analysis showed that serum NPY and TNF-α were independent influencing factors of CP [(OR = 1.029, P < 0.001);(OR = 1.030, P = 0.023)]. The area under the ROC curve of NPY predicting the CP showed statistical significance at a value of 0.819.

CONCLUSION

Together, elevated serum NPY levels seem to be associated with the occurrence of coronary atherosclerosis in Chinese adults.

Autonomic control of ventricular function in health and disease: current state of the art

PURPOSE

Cardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure.

METHODS

Data from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized.

RESULTS

A harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain.

CONCLUSIONS

Although our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.

Upregulation of neuropeptide Y in cardiac sympathetic nerves induces stress (Takotsubo) cardiomyopathy

Substantial emotional or physical stress may lead to an imbalance in the brain, resulting in stress cardiomyopathy (SC) and transient left ventricular (LV) apical ballooning. Even though these conditions are severe, their precise underlying mechanisms remain unclear. Appropriate animal models are needed to elucidate the precise mechanisms. In this study, we established a new animal model of epilepsy-induced SC. The SC model showed an increased expression of the acute phase reaction protein, c-Fos, in the paraventricular hypothalamic nucleus (PVN), which is the sympathetic nerve center of the brain. Furthermore, we observed a significant upregulation of neuropeptide Y (NPY) expression in the left stellate ganglion (SG) and cardiac sympathetic nerves. NPY showed neither positive nor negative inotropic and chronotropic effects. On the contrary, NPY could interrupt β-adrenergic signaling in cardiomyocytes when exposure to NPY precedes exposure to noradrenaline. Moreover, its elimination in the left SG via siRNA treatment tended to reduce the incidence of SC. Thus, our results indicated that upstream sympathetic activation induced significant upregulation of NPY in the left SG and cardiac sympathetic nerves, resulting in cardiac dysfunctions like SC.

Saxagliptin Cardiotoxicity in Chronic Heart Failure: The Role of DPP4 in the Regulation of Neuropeptide Tone

Dipeptidyl-peptidase-4 (DPP4) inhibitors are novel medicines for diabetes. The SAVOR-TIMI-53 clinical trial revealed increased heart-failure-associated hospitalization in saxagliptin-treated patients. Although this side effect could limit therapeutic use, the mechanism of this potential cardiotoxicity is unclear. We aimed to establish a cellular platform to investigate DPP4 inhibition and the role of its neuropeptide substrates substance P (SP) and neuropeptide Y (NPY), and to determine the expression of DDP4 and its neuropeptide substrates in the human heart. Western blot, radio-, enzyme-linked immuno-, and RNA scope assays were performed to investigate the expression of DPP4 and its substrates in human hearts. Calcein-based viability measurements and scratch assays were used to test the potential toxicity of DPP4 inhibitors. Cardiac expression of DPP4 and NPY decreased in heart failure patients. In human hearts, DPP4 mRNA is detectable mainly in cardiomyocytes and endothelium. Treatment with DPP4 inhibitors alone/in combination with neuropeptides did not affect viability but in scratch assays neuropeptides decreased, while saxagliptin co-administration increased fibroblast migration in isolated neonatal rat cardiomyocyte-fibroblast co-culture. Decreased DPP4 activity takes part in the pathophysiology of end-stage heart failure. DPP4 compensates against the elevated sympathetic activity and altered neuropeptide tone. Its inhibition decreases this adaptive mechanism, thereby exacerbating myocardial damage.

Effects of Yiqi Huoxue Decoction on Post-Myocardial Infarction Cardiac Nerve Remodeling and Cardiomyocyte Hypertrophy in Rats

Myocardial infarction can lead to ventricular remodeling and arrhythmia, which is closely related to nerve remodeling. Our previous study found that Yiqi Huoxue decoction (YQHX) can improve ventricular remodeling and reduce myocardial damage. Therefore, in this study, we observed the effect of YQHX on cardiac neural remodeling and cardiomyocyte hypertrophy and its possible mechanism. This research is composed of two parts: animal and H9c2 cells experiments. The animal model of acute myocardial infarction was established by ligating the left anterior descending coronary artery in Sprague Dawley (SD) rats. H9c2 cells were placed in 94% N₂, 5% CO₂, and 1% O₂ hypoxic environment for 12 hours to replicate the hypoglycemic hypoxia model. The experimental results showed that, compared with the MI group, YQHX can significantly improve heart function after myocardial infarction and reduce nerve remodeling and myocardial hypertrophy. Pathological structure observation demonstrated reducing myocardial tissue damage and decreasing of cell cross-sectional area, diameter, and circumference. The positive rate of TH declined apparently, and the sympathetic nerve density was lower than that of the MI group. After YQHX was given for 28 days, the proneural remodeling factors TH, NGF, and GAP43 in the marginal zone of infarction and stellate ganglion decreased obviously while the inhibitory nerve remodeling factor Sema-3A increased. The myocardial hypertrophic protein ANP and β-MHC were also significantly inhibited with p-ERK1/2 protein expression level prominently reduced. There was no difference between the YQHX group and the Meto group. After myocardial infarction, nerve remodeling was seen in the marginal area of infarction and stellate ganglion, and the neuropeptides released by which promoted myocardial hypertrophy. The mechanism may be related to the ERK1/2 signaling pathway. YQHX could regulate the ERK1/2 signaling pathway, inhibit the release of nerve remodeling factors and myocardial hypertrophy protein to reduce nerve remodeling, and relieve myocardial hypertrophy.

Neuropeptide Y Induces Cardiomyocyte Hypertrophy via Attenuating miR-29a-3p in Neonatal Rat Cardiomyocytes

BACKGROUND

Neuropeptide Y (NPY) has been well known to induce Cardiomyocyte Hypertrophy (CH), which is possibly caused by disruption of cardiac cell energy balance. As mitochondria is losely related to energy metabolism, in this study, we investigated the changes in mitochondrial Dynamics-related protein (Drp1) expression under the action of NPY. miRNA-29a, a endogenous noncoding small molecule RNA which is involved in many cardiac diseases, by using a bioinformatics tool, we found a potential binding site of miRNA-29a on the Drp1 mRNA, and suggesting that miRNA-29a might play a regulatory role.

OBJECTIVE

To investigate the role of miR-29a-3p in the process of NPY-induced CH, and further explore it's predicted relationship with Drp1.

METHODS

The expression levels of miR-29a-3p and Atrial Natriuretic Peptide (ANP) were performed by the method of fluorescence quantitative PCR, in addition, expression of Drp1 in treated and control groups were performed by western blot analysis.] Results: We found NPY leads to the CH and up-regulation of ANP expression levels. We also found significant up-regulation of Drp1 expression and down-regulation of miR-29a-3p expression in NPY-treated cells. The decrease in miR-29a-3p expression may lead the increase expression level of Drp1. We found that the expression of ANP increased after NPY treatment. When Drp1 protein was silenced, the high expression of ANP was inhibited.

CONCLUSION

In this study, we found up-regulation of Drp1 in cells treated with NPY. Drp1 mRNA is a predicted target for miR-29a-3p, and the expression of Drp1 was attenuated by miR-29a-3p. Therefore, NPY leads to down-regulation of miR-29a-3p expression, up-regulation of Drp1 expression, and NPY leads to CH. Correspondingly, miR-29a-3p can counteract the effects of NPY. This may be a new way, which could be used in diagnosis and treatment plan for CH.

Neuropeptide Y mediates cardiac hypertrophy through microRNA-216b/FoxO4 signaling pathway

Cardiac hypertrophy (CH) is a major risk factor for heart failure accompanied by maladaptive cardiac remodeling. The role and potential mechanism of neuropeptide Y (NPY) in CH are still unclear. We will explore the role and the mechanism of NPY inactivation (NPY-I) in CH caused by pressure overload. Abdominal aortic constriction (AAC) was used to induce CH model in rats. NPY or angiotensin II (Ang II) was used to trigger CH model in vitro in neonatal rat ventricular myocytes (NRVMs). We found that NPY was increased in the heart and plasma of hypertrophic rats. However, Ang II did not increase NPY expression in cardiomyocytes. NPY-I attenuated CH as decreasing CH-related markers (ANP, BNP and β-MHC mRNA) level, reducing cell surface area, and restoring cardiac function. NPY inactivation increased miR-216b and decreased FoxO4 expression in CH heart. Moreover, NPY decreased miR-216b and increased FoxO4 expression in NRVMs which were reversed by NPY type 1 receptor (NPY1R) antagonist BIBO3304. MiR-216b mimic and FoxO4 siRNA (small interfering RNA) inhibited NPY/Ang II-induced myocardial hypertrophy in vitro. Meanwhile, BIBO3304 reversed the pro-hypertrophy effect of NPY in vitro. Collectively, NPY deficiency attenuated CH by NPY1R-miR-216b-FoxO4 axis. These findings suggested that NPY would be a potential therapeutic target for the prevention and treatment of cardiac hypertrophy.

Peptide YY (PYY) Is Associated with Cardiovascular Risk in Patients with Acute Myocardial Infarction

AIMS

Recent studies have found circulating concentrations of the gastrointestinal hormone GLP-1 to be an excellent predictor of cardiovascular risk in patients with myocardial infarction. This illustrates a yet not appreciated crosstalk between the gastrointestinal and cardiovascular systems, which requires further investigation. The gut-derived hormone Peptide YY (PYY) is secreted from the same intestinal L-cells as GLP-1. Relevance of PYY in the context of cardiovascular disease has not been explored. In this study, we aimed to investigate PYY serum concentrations in patients with acute myocardial infarction and to evaluate their association with cardiovascular events.

MATERIAL AND METHODS

PYY levels were assessed in 834 patients presenting with acute myocardial infarction (553 Non-ST-Elevation Myocardial Infarction (NSTEMI) and 281 ST-Elevation Myocardial Infarction (STEMI)) at the time of hospital admission. The composite outcomes of first occurrence of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke (3-P-MACE), and all-cause mortality were assessed with a median follow-up of 338 days.

RESULTS

PYY levels were significantly associated with age and cardiovascular risk factors, including hypertension, diabetes, and kidney function in addition to biomarkers of heart failure (NT-pro BNP) and inflammation (hs-CRP). Further, PYY was significantly associated with 3-P-MACE (HR: 1.7; 95% CI: 1-2.97; p = 0.0495) and all-cause mortality (HR: 2.69; 95% CI: 1.61-4.47; p = 0.0001) by univariable Cox regression analyses, which was however lost after adjusting for multiple confounders.

CONCLUSIONS

PYY levels are associated with parameters of cardiovascular risk as well as cardiovascular events and mortality in patients presenting with acute myocardial infarction. However, this significant association is lost after adjustment for further confounders.

The Role of Neuropeptide Y in Cardiovascular Health and Disease

Neuropeptide Y (NPY) is an abundant sympathetic co-transmitter, widely found in the central and peripheral nervous systems and with diverse roles in multiple physiological processes. In the cardiovascular system it is found in neurons supplying the vasculature, cardiomyocytes and endocardium, and is involved in physiological processes including vasoconstriction, cardiac remodeling, and angiogenesis. It is increasingly also implicated in cardiovascular disease pathogenesis, including hypertension, atherosclerosis, ischemia/infarction, arrhythmia, and heart failure. This review will focus on the physiological and pathogenic role of NPY in the cardiovascular system. After summarizing the NPY receptors which predominantly mediate cardiovascular actions, along with their signaling pathways, individual disease processes will be considered. A thorough understanding of these roles may allow therapeutic targeting of NPY and its receptors.

Effect of Neuropeptide Y on Action Potential Generation in Working Cardiomyocytes of the Right Atrium in Rat Heart

We studied the effect of neuropeptide Y in concentrations of 10^-8-10^-6 M on electrical activity of adult rat right atrial cardiomyocytes with preserved spontaneous activity. Neuropeptide Y was found to modulate the amplitude-time parameters of action potential: in concentrations of 10^-7 and 10^-6 M it reduced the membrane potential, increased the amplitude of action potential and duration of the repolarization phase, and reduced the frequency of action potential generation. In concentration of 10^-6 M, neuropeptide Y produced stronger effect on the analyzed parameters, while in concentration of 10^-8 M it produced no significant changes.

Neuropeptide Y-mediated sex- and afferent-specific neurotransmissions contribute to sexual dimorphism of baroreflex afferent function

Background

Molecular and cellular mechanisms of neuropeptide-Y (NPY)-mediated gender-difference in blood pressure (BP) regulation are largely unknown.

Methods

Baroreceptor sensitivity (BRS) was evaluated by measuring the response of BP to phenylephrine/nitroprusside. Serum NPY concentration was determined using ELISA. The mRNA and protein expression of NPY receptors were assessed in tissue and single-cell by RT-PCR, immunoblot, and immunohistochemistry. NPY was injected into the nodose while arterial pressure was monitored. Electrophysiological recordings were performed on nodose neurons from rats by patch-clamp technique.

Results

The BRS was higher in female than male and ovariectomized rats, while serum NPY concentration was similar among groups. The sex-difference was detected in Y₁R, not Y₂R protein expression, however, both were upregulated upon ovariectomy and canceled by estrogen replacement. Immunostaining confirmed Y₁R and Y₂R expression in myelinated and unmyelinated afferents. Single-cell PCR demonstrated that Y₁R expression/distribution was identical between A- and C-types, whereas, expressed level of Y₂R was ∼15 and ∼7 folds higher in Ah- and C-types than A-types despite similar distribution. Activation of Y₁R in nodose elevated BP, while activation of Y₂R did the opposite. Activation of Y₁R did not alter action potential duration (APD) of A-types, but activation of Y₂R- and Y₁R/Y₂R in Ah- and C-types frequency-dependently prolonged APD. N-type I_Ca was reduced in A-, Ah- and C-types when either Y₁R, Y₂R, or both were activated. The sex-difference in Y₁R expression was also observed in NTS.

Conclusions

Sex- and afferent-specific expression of Neuropeptide-Y receptors in baroreflex afferent pathway may contribute to sexual-dimorphic neurocontrol of BP regulation.

The role of neuropeptides in adverse myocardial remodeling and heart failure

In addition to traditional neurotransmitters of the sympathetic and parasympathetic nervous systems, the heart also contains numerous neuropeptides. These neuropeptides not only modulate the effects of neurotransmitters, but also have independent effects on cardiac function. While in most cases the physiological actions of these neuropeptides are well defined, their contributions to cardiac pathology are less appreciated. Some neuropeptides are cardioprotective, some promote adverse cardiac remodeling and heart failure, and in the case of others their functions are unclear. Some have both cardioprotective and adverse effects depending on the specific cardiac pathology and progression of that pathology. In this review, we briefly describe the actions of several neuropeptides on normal cardiac physiology, before describing in more detail their role in adverse cardiac remodeling and heart failure. It is our goal to bring more focus toward understanding the contribution of neuropeptides to the pathogenesis of heart failure, and to consider them as potential therapeutic targets.

Trimetazidine attenuates pressure overload-induced early cardiac energy dysfunction via regulation of neuropeptide Y system in a rat model of abdominal aortic constriction

Background

Metabolism remodeling has been recognized as an early event following cardiac pressure overload. However, its temporal association with ventricular hypertrophy has not been confirmed. Moreover, whether trimetazidine could favorably affect this process also needs to be determined. The aim of the study was to explore the temporal changes of myocardial metabolism remodeling following pressure-overload induced ventricular hypertrophy and the potential favorable effect of trimetazidine on myocardial metabolism remodeling.

Methods

A rat model of abdominal aortic constriction (AAC)-induced cardiac pressure overload was induced. These rats were grouped as the AAC (no treatment) or TMZ group according to whether oral trimetazidine (TMZ, 40 mg/kg/d, for 5 days) was administered. Changes in cardiac structures were sequentially evaluated via echocardiography. The myocardial ADP/ATP ratio was determined to reflect the metabolic status, and changes in serum neuropeptide Y systems were evaluated.

Results

Myocardial metabolic disorder was acutely induced as evidenced by an increased ADP/ATP ratio within 7 days of AAC before the morphological changes in the myocardium, accompanied by up-regulation of serum oxidative stress markers and expression of fetal genes related to hypertrophy. Moreover, the serum NPY and myocardial NPY-1R, 2R, and 5R levels were increased within the acute phase of AAC-induced cardiac pressure overload. Pretreatment with TMZ could partly attenuate myocardial energy metabolic homeostasis, decrease serum levels of oxidative stress markers, attenuate the induction of hypertrophy-related myocardial fetal genes, inhibit the up-regulation of serum NPY levels, and further increase the myocardial expression of NPY receptors.

Conclusions

Cardiac metabolic remodeling is an early change in the myocardium before the presence of typical morphological ventricular remodeling following cardiac pressure overload, and pretreatment with TMZ may at least partly reverse the acute metabolic disturbance, perhaps via regulation of the NPY system.

The role of food intake regulating peptides in cardiovascular regulation

Obesity is a risk factor that worsens cardiovascular events leading to higher morbidity and mortality. However, the exact mechanisms of relation between obesity and cardiovascular events are unclear. Nevertheless, it has been demonstrated that pharmacological therapy for obesity has great potential to improve some cardiovascular problems. Therefore, it is important to determine the common mechanisms regulating both food intake and blood pressure. Several hormones produced by peripheral tissues work together with neuropeptides involved in the regulation of both food intake and blood pressure. Anorexigenic (food intake lowering) hormones such as leptin, glucagon-like peptide-1 and cholecystokinin cooperate with α-melanocyte-stimulating hormone, cocaine- and amphetamine-regulated peptide as well as prolactin-releasing peptide. Curiously their collective actions result in increased sympathetic activity, especially in the kidney, which could be one of the factors responsible for the blood pressure increases seen in obesity. On the other hand, orexigenic (food intake enhancing) peptides, especially ghrelin released from the stomach and acting in the brain, cooperates with orexins, neuropeptide Y, melanin-concentrating hormone and galanin, which leads to decreased sympathetic activity and blood pressure. This paradox should be intensively studied in the future. Moreover, it is important to know that the hypothalamus together with the brainstem seem to be major structures in the regulation of food intake and blood pressure. Thus, the above mentioned regions might be essential brain components in the transmission of peripheral signals to the central effects. In this short review, we summarize the current information on cardiovascular effects of food intake regulating peptides.

NPY and stress 30 years later: the peripheral view

Almost 30 years ago, neuropeptide Y (NPY) was discovered as a sympathetic co-transmitter and one of the most evolutionarily conserved peptides abundantly present all over the body. Soon afterward, NPY's multiple receptors were characterized and cloned, and the peptide's role in stress was first documented. NPY has proven to be pivotal for maintaining many stress responses. Most notably, NPY is known for activating long-lasting vasoconstriction in many vascular beds, including coronary arteries. More recently, NPY was found to play a role in stress-induced accretion of adipose tissue which many times can lead to detrimental metabolic changes. It is however due to its prominent actions in the brain, one of which is its powerful ability to stimulate appetite as well as its anxiolytic activities that NPY became a peptide of importance in neuroscience. In contrast, its actions in the rest of the body, including its role as a stress mediator, remained, surprisingly underappreciated and not well understood. Our research has focused on that other, "peripheral" side of NPY. In this review, we will discuss those actions of NPY on the cardiovascular system and metabolism, as they relate to adaptation to stress, and attempt to both distinguish NPY's effects from and integrate them with the effects of the classical stress mediators, glucocorticoids, and catecholamines. To limit the bias of someone (ZZ) who has viewed the world of stress through the eyes of NPY for over 20 years, fresh insight (DH) has been solicited to more objectively assess NPY's contributions to stress-related diseases and the body's ability to adapt to stress.

Neuropeptide Y receptor Y2 gene polymorphism interacts with plasma neuropeptide Y levels in predicting left ventricular hypertrophy in dialysis patients

BACKGROUND

Neuropeptide Y (NPY) is a sympathetic neurotransmitter that acts on multiple receptors involved in cardiovascular remodelling and angiogenesis. Plasma levels of NPY are increased in patients with end-stage renal disease (ESRD) and are independently related to left ventricular hypertrophy (LVH) and incident cardiovascular events in these patients.

OBJECTIVE

To investigate the relationship between NPY receptor Y2 gene polymorphism and left ventricular mass index (LVMI) as well as the interaction between this polymorphism and plasma NPY in determining LVH in 189 ESRD patients.

RESULTS

LVMI was significantly higher (+12%, P = 0.03) in patients carrying the C allele than in those without C allele and was linearly associated with plasma NPY (P = 0.01). Interaction analysis showed a significant NPY-LVMI relationship in patients with the C allele, both at univariate (r = 0.27, P = 0.001) and multivariate (r = 0.21, P = 0.01) analyses, whereas no such relationship existed in patients without this allele. In fully adjusted analyses, a 10 pmol/l increase in plasma NPY entailed a 4.9 g/m increase in LVMI in patients with C allele, whereas the same change in NPY levels did not modify the NPY-LVMI link in patients without such allele (P = 0.009).

CONCLUSION

NPY receptor Y2 polymorphism is independently associated with LVMI and interacts with plasma levels of NPY in explaining the variability of LVH in ESRD. These results offer a genetic basis to the hypothesis that NPY is causally implicated in the pathogenetic pathway leading to LVH in ESRD patients.

Cardiac hypertrophy in neonatal nephrectomized rats: the role of the sympathetic nervous system

Cardiac hypertrophy is frequently encountered in patients with renal failure and represents an independent risk factor for cardiovascular morbidity and mortality. The pathogenesis of cardiac hypertrophy is related to multiple factors, including excess adrenergic activity. This study investigated how renal injury in the early stages of life affects the adrenergic system and thereby potentially influences cardiac growth. Biomarkers of cardiac hypertrophy were used to assess adrenergic function. Newborn male Sprague-Dawley rats were allocated to three groups of five rats each: 5/6 nephrectomy (Nx), pair-fed controls (PF), and sham-operated (SH). Nx animals had significantly higher plasma urea nitrogen, serum creatinine, and mean arterial blood pressure. The heart-weight/body-weight ratio of the Nx cohort was higher than SH and PF (p < 0.001) groups. Plasma norepinephrine (NE) of Nx animals was almost twofold higher than SH and PF (p < 0.01) animals. Compared with SH and PF, Nx animals had higher alpha1A-receptor protein expression, lower cardiac beta1- and beta2-receptor protein expression (p < 0.05), but higher G-protein-coupled receptor kinase-2 (GRK2) expression (p < 0.05). Norepinephrine transporter protein (NET) and renalase protein expression in cardiac tissue from Nx pups were significantly lower than SH and PF. Our data suggest that early age Nx animals have increased circulating catecholamines due to decreased NE metabolism. Enhancement of cardiac GRK2 and NE can contribute to cardiac hypertrophy seen in Nx animals. Furthermore, AKT (activated via alpha1A receptors), as well as increased alpha1A receptors and their agonist NE, might contribute to the observed hypertrophy.