• The Korean Journal of Physiology and Pharmacology
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• v.10 no.6
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• pp.343-347
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• 2006

The present study was designed to investigate the effects renin-angiotensin-aldosterone system (RAAS), endothelin (ET) and local natriuretic peptide (NP) system for glomerulopathy induced in the experimental bilateral ureteral obstructive rats. Sprague-Dawley male rats ($200{\sim}220g$ body weight) were bilaterally obstructed by ligation of the proximal ureters for 24 hours. Control rats were treated in the same ways, except that no ligature was made. The glomeruli were isolated from cortex by graded sieve methods, and the mRNA expressions of local renin-angiotensin system (RAS), aldosterone synthase (CYP11B2), endothelin-1 (ET-1) and NP system were determined by real-time polymerase chain reaction. Following the bilateral ureteral obstruction, the mRNA expressions of renin, angiotensin converting enzyme 1 as well as ET-1 were increased, while that of angiotensin converting enzyme 2 was not changed. The expressions of CYP11B2 and angiotensin II receptors were not changed. C-type natriuretic peptide (CNP) expression was increased, while its receptors (natriuretic peptide receptor-B) were not changed. We suggest that the upregulation of local RAS and ET playa role in the progressive glomerular injury, and that the enhanced CNP activity also plays a compensatory role in obstructive uropathy in the glomerulus.

• The Korean Journal of Physiology and Pharmacology
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• v.4 no.4
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• pp.283-289
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• 2000

Natriuretic peptides comprise a family of three structurally related peptides; atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). The present study was performed to investigate the effect of ANP on the proliferation and activity of ROS17/2.8 and HOS cells which are well-characterized osteoblastic cell lines. ANP dose-dependently decreased the number of ROS17/2.8 and HOS cells after 48-hour treatment. ANP generally increased the alkaline phosphatase activity of ROS17/2.8 and HOS cells after 48 hr treatment, regardless of the fact that basal activity of alkaline phosphatase was much lower in HOS cells compared to that of ROS17/1.8 cells. ANP increased the NBT reduction by ROS17/2.8 and HOS cells. ANP showed the variable but no significant effect on the nitric oxide production by ROS17/2.8 and HOS cells. ROS17/2.8 and HOS cells produced and secreted gelatinase into culture medium, and this enzyme was thought to be the gelatinase A type with the molecular weight determination. The gelatinase activity produced by ROS17/2.8 cells was increased by the treatment of ANP. However, the enzyme activity was not affected by ANP treatment in the HOS cell culture. In summary, ANP decreased the proliferation and increased the alkaline phosphatase activity and NBT reduction of osteoblasts. These results indicate that ANP is one of the important regulators of bone metabolism.

• Journal of mucopolysaccharidosis and rare diseases
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• v.2 no.2
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• pp.46-49
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• 2016

Achondroplasia is autosomal dominant genetic disease and fibroblast growth factor receptor 3 (FGFR3) is currently known to be the only gene that causes achondroplasia. Gain-of function mutation in fibroblast-growth-factor-receptor 3 (FGFR3) causes the disease and C-type natriuretic peptide (CNP) antagonizes FGFR3 downstream signaling by inhibiting the pathway of mitogen-activated protein kinase (MAPK). As FGFR3-related skeletal dysplasias are caused by growth attenuation of the cartilage, chondrocytes appear to be unique in their response to FGFR3 activation. However, the full spectrum of molecular events by which FGFR3 mediates its signaling is just beginning to emerge. This article summaries the mechanisms of FGFR3 function in skeletal dysplasias, the extraordinary cellular manifestations of FGFR3 signaling in chondrocytes, and finally, the progress toward therapy for ACH.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.6
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• pp.667-674
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• 2017

Angiotensin II (Ang II) is metabolized from N-terminal by aminopeptidases and from C-terminal by Ang converting enzyme (ACE) to generate several truncated angiotensin peptides (Angs). The truncated Angs have different biological effects but it remains unknown whether Ang-(4-8) is an active peptide. The present study was to investigate the effects of Ang-(4-8) on hemodynamics and atrial natriuretic peptide (ANP) secretion using isolated beating rat atria. Atrial stretch caused increases in atrial contractility by 60% and in ANP secretion by 70%. Ang-(4-8) (0.01, 0.1, and $1{\mu}M$) suppressed high stretch-induced ANP secretion in a dose-dependent manner. Ang-(4-8) ($0.1{\mu}M$)-induced suppression of ANP secretion was attenuated by the pretreatment with an antagonist of Ang type 1 receptor ($AT_1R$) but not by an antagonist of $AT_2R$ or $AT_4R$. Ang-(4-8)-induced suppression of ANP secretion was attenuated by the pretreatment with inhibitor of phospholipase (PLC), inositol triphosphate ($IP_3$) receptor, or nonspecific protein kinase C (PKC). The potency of Ang-(4-8) to inhibit ANP secretion was similar to Ang II. However, Ang-(4-8) $10{\mu}M$ caused an increased mean arterial pressure which was similar to that by 1 nM Ang II. Therefore, we suggest that Ang-(4-8) suppresses high stretch-induced ANP secretion through the $AT_1R$ and $PLC/IP_3/PKC$ pathway. Ang-(4-8) is a biologically active peptide which functions as an inhibition mechanism of ANP secretion and an increment of blood pressure.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.3
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• pp.149-154
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• 2006

Selective inhibition of phosphodiesterase (PDE) 5 opened a new therapeutic approach for cardiovascular disorders. Therefore, the effect of PDE5 inhibition on the cardiac function should thoroughly be defined. The purpose of the present study was to define the effects of sildenafil, a selective inhibitor of PDE5, on the atrial cGMP efflux, atrial dynamics, and the release of atrial natriuretic peptide (ANP). By perfusing rabbit left atria to allow atrial pacing, changes in atrial stroke volume and pulse pressure, transmural extracellular fluid translocation, cGMP efflux, and ANP secretion were measured. SIN-I, an NO donor and soluble (s) guanylyl cyclase (GC) activator, and C-type natriuretic peptide (CNP), an activator of particulate (p) GC activator, were used. Sildenafil increased basal levels of cGMP efflux slightly but not significantly. Sildenafil in a therapeutic dose increased atrial dynamics (for atrial stroke volume, $2.84{\pm}1.71%$, n=12, vs $-0.71{\pm}0.86%$, n=21; p<0.05) and decreased ANP release ($-9.02{\pm}3.36%$, n=14, vs $1.35{\pm}3.25%$, n=23; p < 0.05), however, it had no effect on the SIN-1- or CNP-induced increase of cGMP levels. Furthermore, sildenafil in a therapeutic dose accentuated SIN-1-induced, but not CNP-induced, decrease of atrial pulse pressure and ANP release. These data indicate that PDE5 inhibition with sildenafil has a minor effect on cGMP levels, but has a distinct effect on pGC-cGMP- and sGC-cGMP-induced contractile and secretory function.

• KSBB Journal
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• v.24 no.6
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• pp.591-597
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• 2009

B-type natriuretic peptide is a neurohormone secreted in the cardiac ventricles. BNP levels are elevated in patients with ventricular dysfunction. Therefore, the concentration of BNP is important factor to reflect diagnosis and prognosis for cardiovascular disease. In this respect, anti-BNP scFv is an urgent requirement for early diagnosis in the field of biosensor. Herein, the genetic codes of anti-BNP scFv were chemically synthesized and cloned into both pET22b (+) and pColdⅣ vector, respectively. The recombinant scFv was successfully expressed as a functional form in cytoplasm of E. coli and detected through Western blot and ELISA. The highest level of functional expression of anti-BNP scFv was achieved using pET22b (+) vector at $15^{\circ}C$ by addition of 0.1 mM IPTG. Additionally, being exposed to both BNP and ANP, anti-BNP scFv specifically captured only BNP. Therefore, anti-BNP scFv expressed in this study will be applied to measure the concentration of BNP as a diagnostic recognition molecule.

• The Korean Journal of Physiology and Pharmacology
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• v.25 no.2
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• pp.159-166
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• 2021

Nicotinamide adenine dinucleotide phosphate oxidases (NOXs) are the major enzymatic source of reactive oxygen species (ROS). NOX2 and NOX4 are expressed in the heart but its role in hypoxia-induced atrial natriuretic peptide (ANP) secretion is unclear. This study investigated the effect of NOX on ANP secretion induced by hypoxia in isolated beating rat atria. The results showed that hypoxia significantly upregulated NOX4 but not NOX2 expression, which was completely abolished by endothelin-1 (ET-1) type A and B receptor antagonists BQ123 (0.3 μM) and BQ788 (0.3 μM). ET-1-upregulated NOX4 expression was also blocked by antagonists of secreted phospholipase A2 (sPLA2; varespladib, 5.0 μM) and cytosolic PLA2 (cPLA2; CAY10650, 120.0 nM), and ET-1-induced cPLA2 expression was inhibited by varespladib under normoxia. Moreover, hypoxia-increased ANP secretion was evidently attenuated by the NOX4 antagonist GLX351322 (35.0 μM) and inhibitor of ROS N-Acetyl-D-cysteine (NAC, 15.0 mM), and hypoxia-increased production of ROS was blocked by GLX351322. In addition, hypoxia markedly upregulated Src expression, which was blocked by ET receptors, NOX4, and ROS antagonists. ET-1-increased Src expression was also inhibited by NAC under normoxia. Furthermore, hypoxia-activated extracellular signal-regulated kinase 1/2 (ERK1/2) and protein kinase B (Akt) were completely abolished by Src inhibitor 1 (1.0 μM), and hypoxia-increased GATA4 was inhibited by the ERK1/2 and Akt antagonists PD98059 (10.0 μM) and LY294002 (10.0 μM), respectively. However, hypoxia-induced ANP secretion was substantially inhibited by Src inhibitor. These results indicate that NOX4/Src modulated by ET-1 regulates ANP secretion by activating ERK1/2 and Akt/GATA4 signaling in isolated beating rat hypoxic atria.

• Journal of Veterinary Clinics
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• v.38 no.5
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• pp.215-220
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• 2021

The purpose of this study was to investigate the correlation between vertebral left atrial size (VLAS) and NT-proBNP levels. Sixty-three dogs with myxomatous mitral valve disease (MMVD) were recruited for this study. The MMVD group was classified according to the ACVIM stage based on medical history, clinical signs, and thoracic radiography and echocardiography findings. The N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured using fluorescent immunoassay. VLAS and VHS values were measured using a digital caliper in the right lateral view. There were significant differences in VLAS for each American college of veterinary internal medicine (ACVIM) stage (p < 0.01). As the ACVIM stage increased, it tended to increase. Vertebral heart score (VHS) also showed a tendency to increase with the ACVIM stage (p < 0.01). VLAS was divided into three groups: VLAS <2.6, 2.6≤ VLAS <3.1, and VLAS ≥3.1. NT-proBNP values were significantly different between the three groups (p < 0.01), and VLAS and NT-proBNP values showed a strong positive correlation (r = 0.756, p < 0.01). In conclusion, there were significant differences among ACVIM stages B1 and B2, B1 and C-D, and B2 and C-D groups regarding VLAS. Furthermore, NT-proBNP increased proportionally as VLAS increased. Measurements of VLAS may be helpful in the diagnosis of MMVD in addition to the existing radiological and echocardiographic methods.

• Clinical and Experimental Pediatrics
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• v.56 no.12
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• pp.519-522
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• 2013

Timely diagnosis of hyponatremia is important for preventing potential morbidity and mortality as it is often an indicator of underlying disease. The most common cause of eurvolemic hyponatremia is the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Recent studies have demonstrated that proinflammatory cytokines such as interleukin (IL) $1{\beta}$ and IL-6 are involved in the development of hyponatremia, a condition that is associated with severe inflammation and is related to antidiuretic hormone (ADH) secretion. Serum sodium levels in hyponatremia are inversely correlated with the percentage of neutrophils, C-reactive protein, and N-terminal-pro brain type natriuretic peptide. Additionally, elevated levels of serum IL-6 and IL-$1{\beta}$ are found in inflammatory diseases, and their levels are higher in patients with hyponatremia. Because it is significantly correlated with the degree of inflammation in children, hyponatremia could be used as a diagnostic marker of pediatric inflammatory diseases. Based on available evidence, we hypothesize that hyponatremia may be associated with inflammatory diseases in general. Understanding the mechanisms responsible for augmented ADH secretion during inflammation, monitoring patient sodium levels, and selecting the appropriate intravenous fluid treatment are important components that may lower the morbidity and mortality of patients in a critical condition.

• Journal of Veterinary Clinics
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• v.37 no.6
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• pp.311-316
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• 2020

Biomarkers used in dogs with heartworm disease include N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac troponin I (cTnI), which are associated with damage to the myocardium. Pulmonary hypertension is one of the clinical signs of canine heartworm disease. The purpose of this study is to investigate the change in the concentration of each biomarker, severity of pulmonary hypertension and the correlation between biomarkers according to the severity of clinical signs. Five healthy dogs and 10 heartworm-infected dogs were recruited for the study. The heartworm-infected group was classified based on the history, clinical signs, and blood assay, thoracic radiography, and echocardiography after confirming the infection according to the results of the commercial ELISA kit (SNAP test, IDEXX Laboratories, Maine, USA). NT-proBNP was higher in the severely infected group than the control group (p < 0.05); cTnI was also higher in the severely infected group than the control group (p < 0.05). The pressure gradient of pulmonary hypertension was higher in the severe group than the mild group (p < 0.05). The severity of pulmonary hypertension was correlated with NT-proBNP (r = 0.818, p < 0.01), cTnI (r = 0.894, p < 0.01). When the correlation of the two serum values for each group was examined, a correlation was not found in the mild group (r = 0.707, p = 0.182), but a correlation was found in the severe group (r = 0.9, p < 0.05). NT-proBNP and cTnI were significantly increased and correlated with severe clinical signs. Pulmonary hypertension was significant higher in the severe group than in the mild group (p < 0.05). Evaluation of blood biomarker concentration and severity of pulmonary hypertension and referring to each correlation between these indicators may be helpful to assess the severity of the heartworm disease.