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Natriuretic Peptides*

Cardiovascular Diseases ; Humans ; Natriuretic Peptides

The measurements of B-type natriuretic peptide (BNP) or N-terminal proBNP (NT-proBNP), when taken together with conventional clinical assessment, may assist in making the prognosis and also for making serial adjustment of such treatment. But although such commercial assays are currently approved for the diagnosis of heart failure, the role of the natriuretic peptides for monitoring the success of congestive heart failure (CHF) therapy has not as yet been submitted for regulatory approval. Moreover, because of the intra-individual biologic variation of the BNP or because of multiple factors that affect the BNP levels, the magnitude of the change of BNP levels must be large to confidently interpret BNP changes within an individual, and just how large has not been determined. Yet the levels of plasma BNP and NT-pro BNP are well correlated with the concurrent haemodynamic measurements and indicators of left ventricular systolic function. Also, BNP and NT-pro BNP serve as significant prognostic information and it is possible that adjustment of anti-heart failure therapy according to serial measurements of BNP (in addition to the standard clinical assessment) may offer improved outcomes. Better understanding of the test characteristics is needed before we can effectively use this valuable test to guide therapeutic strategies.
Diagnosis ; Heart Failure* ; Heart* ; Humans ; Natriuretic Peptide, Brain* ; Natriuretic Peptides ; Plasma ; Prognosis

AIMTo investigate the effect of vasonatrin peptide (VNP) on the expression of C-type natriuretic peptide receptor (NPR-C) in hypoxic rat hearts.

METHODSRats were divided randomly into three groups: control group, hypoxia group(3-28 d) and VNP (25-75 microg/kg per day) + hypoxia group. The plasma concentration of atrial natriuretic peptide (ANP) in rats was measured by the means of radioimmunoassay. Furthermore, quantitative PCR was used to examine the NPR-C mRNA level in rat hearts.

RESULTSThe plasma concentration ANP in rats was significantly higher than that of control group, and VNP (75 microg/kg per day) made it more higher. Hypoxia for 3 day of had no significant effect on the NPR-C mRNA level in rat hearts, while hypoxia for 7-28 d significantly increased the level of NPR-C mRNA in a time dependent manner. VNP (50-75 microg/kg per day) significantly reduced the NPR-C mRNA level in rat hearts in a dose dependent manner.

CONCLUSIONVNP increases the plasma concentration of ANP in hypoxic rats. Hypoxia can increase expression of NPR-C in rat hearts significantly, which can be inhibited by VNP.

Animals ; Atrial Natriuretic Factor ; blood ; pharmacology ; Hypoxia ; metabolism ; Male ; Natriuretic Peptide, C-Type ; metabolism ; Natriuretic Peptides ; metabolism ; Rats ; Rats, Sprague-Dawley ; Receptors, Atrial Natriuretic Factor ; metabolism

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.
Alkaline Phosphatase ; Atrial Natriuretic Factor ; Cell Culture Techniques ; Cell Line ; Gelatinases ; Humans ; Matrix Metalloproteinase 2 ; Metabolism ; Molecular Weight ; Natriuretic Peptide, Brain ; Natriuretic Peptide, C-Type ; Natriuretic Peptides ; Nitric Oxide ; Osteoblasts* ; Peptides

BACKGROUND: Cardiac atrium is an endocrine gland secreting a family of natriuretic peptides. The secretion of atrial natriuretic peptide(ANP) had been shown to be controlled by variable factors. The change in atrial dynamics have been considered as one of the most prominent stimuli for the stimulation of ANP secretion. Hypoxic stress has been shown to increase cardiac ANP secretion. However, the mechanism by which hypoxia increases ANP secretion cardiac ANP secretions. However, the mechanism by which hypoxia increases ANP secretion has not to be defined. Therefore, the purpose of the present study was tow-fold: to develop a protocol to defined the effect of hypoxia on ANP secretion in perfused beating rabbit atria and to clarify the mechanism responsible for the accentuation by hypoxia of ANP secretion. MATERIAL AND METHOD: Experiments have been done in perfused beating rabbit atria. ANP was measured by radioimmunoassay. RESULT: Hypoxic stimulus with nitrogen decreased atrial stroke volume. The decrease in atrial stroke volume recovered basal level during the period of recovery with oxygen. ANP secretion and the concentration of perfusate ANP in terms of extracellular fluid(ECF) translocation which reflects the rate of myocytic release of ANP were increased by hypoxia and returned to basal levels during the recovery. Changes in ECF translocation paralleled by hypoxia and returned to basal levels during the recovery. Changes in ECF translocation paralleled to that of atrial stroke volume. At the start of recovery in atrial storke volume, ECF tranalocation incrased for several minutes. The above responses were stable and reproducible. Glibenclamide treatment prevented the recovery in atrial stroke volume. Increments by hypoxia of ANP secretion and ANP concentration were suppressed by glibenclamide. CONCLUSIONS: These results indicate that hypoxia incrased atrial myocytic ANP release and that the mechanism responsible for the accentuation is partially related to the change in K+ATP channel activity.
Anoxia ; Atrial Natriuretic Factor* ; Endocrine Glands ; Glyburide ; Heart Atria ; Humans ; Natriuretic Peptides ; Nitrogen ; Oxygen ; Radioimmunoassay ; Stroke Volume

BACKGROUND: N-terminal fragment of pro Brain Natriuretic Peptide (NT-pro BNP) is a neuro-hormone synthesized from the cardiac ventricles in response to increased wall tension. The purpose of this study was to assess the correlation between NT-pro BNP levels and New York Heart Association function class (NYHA Fc) and echocardiographic findings in patients, who visited cardiology department. METHODS: From October, 2002 to April, 2003, serum NT-pro BNP levels were measured in 348 patients, who visited Samsung Medical Center and Jong Koo Lee Heart Clinic. RESULTS: NT-pro BNP levels were increased with the progression of NYHA Fc of dyspnea (p<0.001 by ANOVA) as well as with the increase in systolic left ventricular internal dimension (p<0.05) and the decrease in ejection fraction (p<0.01). In NYHA Fc I patients, NT-pro BNP levels were positively correlated with age (p<0.001) and left atrial size (p<0.001). In patients with ischemic heart disease, NT-pro BNP levels were also positively correlated with NYHA Fc (p<0.001 by ANOVA). NT-pro BNP levels were increased with the increase in systolic (p<0.001) and diastolic (p=0.017) left ventricular internal dimension as well as the decrease in ejection fraction (p<0.001). The area under the receiver operating characteristic (ROC) curve for NT-pro BNP levels was 0.994 (95% confidence interval, 0.979-0.999), and the most reliable cut-off level of NT-pro BNP was 293.6 pg/mL. CONCLUSION: NT-pro BNP levels were positively correlated with NYHA Fc of dyspnea and systolic dysfunction in patients, who visited cardiology department. A 300 pg/mL of NT-pro BNP level appears to be a sensitive level to differentiate dyspnea of heart origin or not in patients, who visited cardiology department.
Cardiology ; Dyspnea ; Echocardiography ; Heart Failure* ; Heart Ventricles ; Heart* ; Humans ; Myocardial Ischemia ; Natriuretic Peptide, Brain ; Natriuretic Peptides ; ROC Curve

BACKGROUND AND OBJECTIVES: The role of preoperative transthoracic echocardiography (TTE) for the risk stratification has not been well investigated yet. We compared the predictive power of TTE with N-terminal pro-brain natriuretic peptide (NT-proBNP), a representative biomarker that predicts perioperative cardiovascular risk, and investigated whether these tests have incremental value to the clinically determined risk. SUBJECTS AND METHODS: We evaluated the Revised Cardiac Risk Index (RCRI), TTE, and NT-proBNP in 1,923 noncardiac surgery cases. The primary endpoint was a perioperative major cardiovascular event (PMCE), which was defined by any single or combined event of secondary endpoints including myocardial infarction, development of pulmonary edema, or primary cardiovascular death within 30 days after surgery. RESULTS: All echocardiographic parameters including left ventricular ejection fraction, regional wall motion score index, and transmitral early diastolic velocity/tissue Doppler mitral annular early diastolic velocity (E/E') were predictive of PMCE (c-statistics=0.579+/-0.019 to 0.589+/-0.015), but none of these parameters were better than the clinically determined RCRI (c-statistics=0.594+/-0.019) and were inferior to NT-proBNP (c-statistics=0.748+/-0.019, p<0.001). The predictive power of RCRI {adjusted relative risk (RR)=1.4} could be improved by addition of echocardiographic parameters (adjusted RR=1.8, p<0.001), but not to that extent as by addition of NT-proBNP to RCRI (adjusted RR=3.7, p<0.001). CONCLUSION: TTE was modestly predictive of perioperative cardiovascular events but was not superior to NT-proBNP. Moreover, it did not have incremental value to the clinically determined risk. The results of our study did not support the use of routine echocardiography before noncardiac surgery.
Cardiovascular Diseases ; Echocardiography ; Humans ; Myocardial Infarction ; Natriuretic Peptide, Brain ; Natriuretic Peptides ; Peptide Fragments ; Postoperative Complications ; Pulmonary Edema ; Stroke Volume

BACKGROUND: Head-down suspension (HDS) of rats has been used as a model for simulation of a microgravity environment. C-type natriuretic peptides (CNP) and atrial natriuretic peptide (ANP) are produced in the central nervous system, especially in hypothalamus, to complement their peripheral natriuretic effects. Therefore, this study investigated the changes in the central adaptations of hypothalamic ANP and CNP syntheses to 4 weeks of HDS in rats. METHODS: Unanesthetized, unrestrained, male Sprague-Dawley rats were subjected to either a horizontal position (control rats) or a -45 degrees head-down tilt using the tail-traction technique (HDS rats). We determined the hypothalamic syntheses of natriuretic peptides as an expression of ANP and CNP mRNA. The expression of natriuretic peptide mRNA was measured by reverse transcription-polymerase chain reaction with [32P]-dCTP following 4 weeks of HDS in the hypothalamus of control and HDS rats. RESULTS: After 4 weeks of HDS, the expression of ANP mRNA showed a decreasing trend in the hypothalamus of HDS rats. In contrast with ANP, CNP mRNA expression was significantly (p<0.01) increased in the hypothalamus of HDS rats. There were different changes in the hypothalamic CNP and ANP mRNA expressions of HDS rats compared with that of the control rats.CONCLUSION: These results represent that the hypothalamic syntheses of natriuretic peptides are differently responded and the role of CNP is augmented to compensate for the decrement of ANP action in the central nervous system following 4 weeks of HDS.
Animals ; Atrial Natriuretic Factor ; Central Nervous System ; Complement System Proteins ; Head-Down Tilt ; Humans ; Hypothalamus ; Male ; Natriuretic Agents ; Natriuretic Peptides ; Rats* ; Rats, Sprague-Dawley ; RNA, Messenger* ; Weightlessness

BACKGROUND: Recently, B-natriuretic peptide (BNP) level and left atrial volume index (LAVi) were known to correlate with indices of LV diastolic function. As a screening method, we tried to evaluate the efficacy to BNP, ANP, and LAVi to predict the advanced diastolic dysfunction that means myocardial relaxation abnormality and elevated LV filling pressure. METHODS: In 100 patients who referred for echocardiography, Doppler recording of the mitral inflow and tissue Doppler imaging of the mitral annulus were obtained and classified into 4 diastolic function grades (normal, impaired relaxation, pseudonormal, and restrictive). Advanced diastolic dysfunction was defined as pseudonormal and restrictive physiology. LAVi was measured by modified Simpson's method in apical 4-chamber view at end-systole. Plasma levels of BNP and ANP were measured on the same day as echocardiogram was done. RESULTS: BNP and ANP levels were increased as diastolic function grade was worsening (BNP : 60+/-92, 108+/-204, 778+/-1,023 and 1,426+/-1,421 pg/ml, p<0.001; ANP: 22+/-30, 23+/-26, 94+/-92, 96+/-61 pg/ml, p<0.001). LAVi was also increased as diastolic dysfunction was advanced: 24+/-7 ml/m2, 27+/-9 ml/m2, 37+/-12 ml/m2, 45+/-12 ml/m2, p<0.001. The areas under the curve of receiver-operator characteristic curve for BNP, ANP and LAVi to detect the advanced diastolic dysfunction were 0.91, 0.88 and 0.84, respectively. BNP of 137 pg/ml, ANP of 34 pg/ml, and LAVi of 30 ml/m2 were the best values of sensitivity and specificity, respectively. CONCLUSION: These data suggest that BNP, ANP and LAVi provide meaningful sensitivity and specificity for the detection of advanced diastolic dysfunction, respectively. Among these, BNP is better than ANP or LAVi for the screening method to predict the advanced diastolic dysfunction.
Atrial Natriuretic Factor ; Diastole ; Echocardiography, Doppler ; Heart Atria ; Humans ; Mass Screening* ; Natriuretic Peptide, Brain ; Natriuretic Peptides* ; Physiology ; Plasma ; Relaxation ; Sensitivity and Specificity