BNP Concentrations Research Articles

A survey of coronary risk factors and B-type natriuretic peptide concentrations in cardiac nurses from Europe: do nurses still practice what they preach?

From a previous survey of cardiac nurses attending a scientific conference, we learned that these nurses adopted a healthier lifestyle than the general population. The aim of this study was to determine the overall profile of cardiac risk factors in a similar cohort and determine whether cardiac nurses continue to 'practice what they preach' in this regard. Secondly, we examined the practical value of screening a large cohort of individuals within a short time frame (total of 8 hours screening time) and determined the range of BNP concentrations within a 'healthy' cohort. Data on CHD risk factors were collected with a short self-report questionnaire. The sample consisted of 122 cardiac nurses from 19 countries attending a European cardiac nursing conference held in Stockholm. A venous blood sample was collected into a tube containing potassium ETDA. B-type natriuretic peptide was measured on-site with the use of a portable fluorescence immunoassay kit. Most participants were female (89%). Participants ranged in age from 23 to 60 years with a mean age of 41 (S.D. 9.4). Eleven percent - all female - reported they were current smokers, 27% (34) had a BMI >25 and 27% of the sample stated they did not exercise regularly. Almost half (48%) of the sample reported a family history of CHD. As expected, all BNP-values were within the normal range. There were significant differences in BNP on the basis of sex (P<0.05) and age (P<0.05) and a trend towards increasing BNP concentrations with progressively higher BMI scores (P=0.06). This study reconfirms the likelihood that many cardiac nurses heed their own advice on lifestyle modification to reduce cardiovascular risk and therefore provide a good role model for the promotion of primary and secondary prevention initiatives.

Correlation of plasma concentrations of B-type natriuretic peptide with infarct size quantified by tomographic thallium-201 myocardial scintigraphy in asymptomatic patients with previous myocardial infarction.

Secretion of A-type (atrial) and B-type (brain) natriuretic peptides (ANP and BNP) increases in relation to left ventricular (LV) dysfunction in patients with myocardial infarction (MI). However, it is unknown what determines the concentrations of ANP and BNP in asymptomatic MI patients with preserved LV function, so the aim of the present study was to examine if they are associated with MI size. Plasma concentrations of ANP and BNP in the peripheral blood were measured in 88 asymptomatic (New York Heart Association class I) patients with previous MI. The infarct size was quantitatively calculated from rest thallium-201 myocardial single photon emission computed tomography. In multivariate linear regression analysis that included MI size, hemodynamic parameters, and age as covariables, only BNP concentrations had a significant association with MI size (p=0.0001). In contrast, ANP concentrations were not significantly correlated with MI size in either the univariate or multivariate analysis. BNP but not ANP concentrations increased in proportion to the scintigraphic MI size despite the lack of heart failure in asymptomatic patients with previous MI. Thus, the increase in plasma BNP concentrations reflects the MI size, an important determinant of prognosis, in asymptomatic patients with MI.

Diagnostic Potential of Natriuretic Peptides in the Occult Phase of Golden Retriever Muscular Dystrophy Cardiomyopathy

The objective of the study was to determine whether the plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP, respectively) could be reliable markers of cardiac alterations during occult cardiomyopathy in Golden Retriever Muscular Dystrophy (GRMD). Fifty Golden Retrievers without any clinical or radiographic sign of heart disease were included in this study (21 GRMD dogs and 29 controls). Controls and GRMD dogs were divided into 2 subgroups according to age (< and > or =12 months old, respectively). All dogs underwent echocardiography and determination of BNP and ANP plasma concentrations by radioimmunoassay. No ventricular dilatation or dysfunction was observed in either control or GRMD dogs. ANP plasma concentration did not differ significantly between controls and GRMD dogs (mean +/- SD = 72 +/- 49 versus 58 +/- 23 pg/mL, respectively, P = .21). This finding was confirmed in both subgroups of dogs (ie, those < and > or =12 months old). In contrast, BNP plasma concentrations were significantly higher in GRMD dogs than in controls (mean +/- SD = 117 +/- 92 versus 46 +/- 22 pg/mL, respectively, P < .05). In dogs > or =12 months old, sensitivity and specificity of BNP for identifying GRMD with a cutoff of 65 pg/mL were 78 and 86%, respectively. For the same cutoff value, sensitivity dropped to 42%, whereas specificity reached 100% in dogs <12 months old. In conclusion, BNP may be a useful biochemical marker of asymptomatic cardiomyopathy. However, this peptide does not allow very early detection because its optimal discriminatory power was observed in adult dogs (ie, > or =12 months of age).

Pressão arterial e concentração plasmática do peptídeo atrial natriurético e do peptídeo natriurético tipo B, em gestações complicadas pela pré-eclâmpsia

OBJETIVO: o estudo busca determinar a existência de associação entre a elevação da pressão arterial e os níveis plasmáticos dos peptídeos natriuréticos ANP e BNP, na gestação complicada pela pré-eclâmpsia. MÉTODOS: em estudo transversal caso-controle, pareado por idade gestacional, 25 grávidas normotensas e 61 portadoras de pré-eclâmpsia foram avaliadas quanto ao nível da pressão arterial e às concentrações plasmáticas dos peptídeos natriuréticos ANP e BNP. Exames clínico e laboratoriais foram realizados para o diagnóstico de pré-eclâmpsia, sendo a pressão arterial medida de forma não invasiva. As dosagens hormonais foram obtidas por radioimunoensaio, após extração em colunas Sep-pak C18. Os valores médios das concentrações plasmáticas do ANP e BNP foram comparados entre grupos com pressão arterial progressivamente maiores. A correlação entre os valores da pressão arterial e os níveis plasmáticos do ANP e BNP no sangue materno foi também investigada pela de análise de regressão no grupo completo de gestantes e em grupos específicos excluindo-se a hipertensão anterior à gestação e, em seguida, excluindo-se aquelas sem hipertensão prévia. RESULTADOS: os valores plasmáticos de ANP foram 41.5±7.3, 78.4±13.1 e 89.2±13.4 pg/mL (p<0,00001) e os de BNP plasmático foram 79.5±15.8, 176.7±42.2 e 208.3±63.5 pg/mL (p=0,005), respectivamente, para os grupos de pressão arterial média =107 mmHg, 107-139 mmHg e =140 mmHg. Verificou-se correlação positiva entre as concentrações plasmáticas do ANP e os níveis pressóricos na pré-eclâmpsia, independente da existência de estado hipertensivo prévio à gestação (p<0,0001 para pré-eclâmpsia e p<0,01 para pré-eclampsia sobreposta à hipertensão arterial crônica), ao passo que as dosagens de BNP não se mostraram associadas à pressão arterial no grupo com hipertensão arterial prévia à gestação (p=0,004 para pré-eclâmpsia e p=0,18 para pré-eclampsia sobreposta à hipertensão arterial crônica). CONCLUSÃO: o agravamento da hipertensão na pré-eclâmpsia correlacionou-se com as concentrações séricas do ANP e BNP, embora os valores do BNP possam ser influenciados pela existência de estado hipertensivo prévio.

Influence of cardiopulmonary bypass (CPB) on the natriuretic peptides ANP and BNP. A comparison between long and short duration of CPB and off pump surgery

Plasma atrial and brain natriuretic peptide (ANP and BNP) are cardiac hormones secreted mainly due to cardiac overload. The study was designed to assess plasma concentrations of ANP and BNP in patients undergoing coronary bypass grafting (CABG) with long and short duration of cardiopulmonary bypass (CPB) and without CPB (off-pump surgery). We studied 45 patients scheduled for elective CABG. Patients were allocated in three groups: group A received CPB with a duration less than 60 minutes, group B more than 60 minutes and patients without CPB were allocated in group C. ANP and BNP were measured after induction of anaesthesia (T0), at the end of surgery (T1), 4 hrs. (T2), 24 hrs. (T3) and 120 hrs. postoperatively (T4). In all groups, ANP-levels increased from T0 to T4 (group A: from 3.7 +/- 2.1 to 8.9 +/- 8.0; group B: from 3.3 +/- 1.7 to 8.0 +/- 6.0; group C: from 3.0 +/- 1.6 to 5.3 +/- 2.3 pg/ml), but there were no significant differences between the groups. BNP-concentrations increased also from T0 to T4 (group A: from 34 +/- 18 to 234 +/- 164; group B: from 33 +/- 26 to 219 +/- 182; group C: from 33 +/- 24 to 77 +/- 55 pg/ml). Furthermore we measured significant higher BNP-levels in group B compared to group C at T3 and T4. No significant differences between group A and B were found. CPB influenced BNP, but not ANP plasma concentrations. An influence of the duration of CPB on ANP and BNP was not seen.

Effect of Natriuretic Peptides on in vitro Stimulated Adrenocorticotropic Hormone Release and Pro-Opiomelanocortin mRNA Expression by the Fetal Rat Pituitary Gland in Late Gestation

Objective and Methods: We investigated the effects of individual natriuretic peptides (atrial natriuretic peptide, ANP; brain natriuretic peptide, BNP, and C-type natriuretic peptide, CNP) on rat corticotropin-releasing factor stimulated adrenocorticotropic hormone (ACTH) secretion by the pituitary gland of 21-day-old rat fetuses in vitro and on pro-opiomelanocortin gene expression using in situ hybridization. Results: Graded concentrations of ANP, BNP, or CNP (10^–10, 10^–9, and 10^–8 mol/l) induced a log dose dependent inhibition of ACTH secretion induced by rat corticotropin-releasing factor (10^–10 mol/l). These natriuretic peptides showed equipotent effects on a molar basis. Moreover, ANP, BNP, or CNP at 10^–10 mol/l reduced significantly the pituitary pro-opiomelanocortin mRNA expression. In addition, the immunoreactive ANP, BNP, and CNP cells were localized in the anterior lobe, but not in the intermediate lobe of the fetal pituitary gland. Conclusions: These data suggest that the fetal pituitary gland may be both a source and a target for natriuretic peptides that might control ACTH synthesis and release via an endocrine and/or paracrine mechanism. The natriuretic peptides could participate, as well as glucocorticoids, in the control of the corticotropin-stimulating activity of the fetal rat in late gestation.

Effect of an ACE inhibitor and an AT1 receptor antagonist on cardiac hypertrophy.

The effect of long-term administration of delapril, an angiotensin converting enzyme inhibitor, and candesartan, an angiotensin II receptor blocker, on cardiac hypertrophy was investigated in spontaneously hypertensive rats (SHR). Delapril (2 mg/kg/ day) and candesartan (2 mg/kg/day) were administered for 5 weeks to 15-week-old male SHR. Echocardiographic estimation of cardiac morphology and function revealed cardiac hypertrophy in SHR compared with Wistar-Kyoto rats (WKY) which were used as normal controls. Both treated groups revealed regression of cardiac hypertrophy estimated by echocardiography. Heart to body weight ratio of treated SHR was also smaller than that of untreated SHR. Plasma BNP and ANP concentrations were increased in untreated SHR and decreased in the treated groups. Histological examination was performed using light microscopy and the area of fibrosis was estimated by computer. Reduction of the fibrotic area was observed in SHR treated with delapril and candesartan, although the latter was not statistically significant. Immunohistochemical examination using anti-collagen monoclonal antibody showed a decrease of type I collagen in treated SHR as compared with untreated SHR. It is concluded that both angiotensin converting enzyme inhibitor and angiotensin II receptor blocker sufficiently reduce blood pressure in SHR associated with regression of cardiac remodeling.

The role of brain natriuretic peptide in population screening.

While measurement of plasma BNP concentration has been shown to be useful in the diagnosis of heart failure, its role as a screening test for detection of pre-clinical ventricular remodeling or dysfunction in the general population has not been established. Here we review available population-based studies assessing the predictive characteristics of BNP for the detection of pre-clinical structural heart disease (Stage B Heart Failure).

Corrélation entre les valeurs du BNP plasmatique et les mesures isotopiques de la fraction d’éjection ventriculaire gauche

Brain Natriuretic Peptide is a biological marker used for the diagnosis of the left ventricular dysfunction. The aim of our study is to find correlation between BNP and Left Ventricular Ejection Fraction (LVEF) measured by radionuclide ventriculography. Patients from the cardiology department for measurement of the LVEF, had at the same times a measurement of BNP plasma levels. 89 patients had been included (75 men and 15 women) in study. 4 groups of patients have been made according to their pathology (ischaemic heart desease, non ischaemic dilated cardiomyopathy, hypertrophic cardiomyopathy and valvular heart deseases). Also, we have distinguished 2 sub-groups according to the result of LVEF: patients having LVEF ≥ 52% with median plasma concentration = 34pg/ml (18–91.5), and patients having LEVF < 52% with median plasma concentration = 111pg/ml (49–457). Significant difference was found between those 2 sub-groups by Mann Withney Wilcoxon test ( p = 0.0005). Among patients with LVEF < 52%, a significant negative correlation between plasma BNP concentration and LVEF was found (Spearmann r = –0.576). In conclusion, the plasma BNP concentration is a reliable parameter to explore the left ventricular dysfunction.

The time course of natriuretic hormones as plasma markers of myocardial recovery in heart transplant candidates during ventricular assist device support reveals differences among device types

Background: The natriuretic hormones ANP and BNP are expressed differently in the myocardium. Both hormones have compensatory diuretic activity during heart failure. Mechanical stretch of the myocardial walls induces the expression of these hormones. In failing human myocardium, both ANP and BNP are transcribed in the ventricular myocardium in high amounts. We measured the plasma concentrations of ANP and BNP in patients supported by various ventricular assist devices (VADs) at various times. We analyzed the time courses of ANP and BNP to determine (1) the time scale of their down-regulation as a marker of putative myocardial recovery, (2) their steady-state levels under VAD support and (3) differences caused by various VAD devices. Methods: We analyzed ANP and BNP using commercially available radioimmune assays. We analyzed the time courses of patients supported by Thoratec® (THO) LVAD ( n = 8), TCI Heartmate® (TCI) ( n = 6), Novacor® (NOV) ( n = 7), and Lionheart® (LIO) ( n = 3). Results: Patients supported with NOV and some patients with TCI showed down-regulation of BNP to a steady-state level at 30 to 50 days, following a single exponential decay. In contrast, patients supported by THO or LIO did not reveal a determined time course of the natriuretic hormones. Only a few patients reached normal plasma values during VAD support. Conclusion: The time courses of ANP and BNP differ among VAD types because of construction and/or driving mode, which might be important when considering patients for weaning from VAD without heart transplant.

Measurement of plasma brain natriuretic peptide level as a guide for cardiac overload.

We examined whether measurement of the plasma BNP concentrations might be useful for the early diagnosis of the existence and severity of disease in patients with heart disease in daily clinical practice. The plasma BNP and ANP concentrations in 415 patients with heart disease and hypertension and 65 control subjects were measured. Patients with heart disease had higher plasma BNP and ANP concentrations than did those with hypertension or control subjects. Among the etiology of cardiac diseases, specifically dilated cardiomyopathy and hypertrophic cardiomyopathy, was associated with the highest plasma BNP concentrations, whereas dilated cardiomyopathy was associated with the highest plasma ANP concentrations. Plasma BNP concentrations showed an increase as the severity of the heart disease, as graded according to the NYHA classification of cardiac function, increased. In both patients with heart disease and hypertension, the plasma BNP values were higher in those who had abnormalities in their echocardiogram and electrocardiogram as compared to those without any abnormalities. The plasma BNP levels also showed a significant correlation with left ventricular wall thickness and left ventricular mass. On the other hand, the plasma ANP levels showed significant correlations with left ventricular dimension. Receiver operative characteristic analysis revealed that plasma BNP levels showed substantially high sensitivity and specificity to detect the existence of heart diseases. Measurements of the plasma BNP concentrations is useful to detect the existence of the diseases, and abnormalities of left ventricular function and hypertrophy in patients with heart disease in daily clinical practice.

Brain natriuretic peptide appears to act locally as an antifibrotic factor in the heart

In addition to cardiac myocyte hypertrophy, proliferation and increased extracellular matrix production of cardiac fibroblasts occur in response to cardiac overload. This remodeling of the cardiac interstitium is a major determinant of pathologic hypertrophy leading to ventricular dysfunction and heart failure. Atrial and brain natriuretic peptides (ANP and BNP) are cardiac hormones produced primarily by the atrium and ventricle, respectively. Plasma ANP and BNP concentrations are elevated in patients with hypertension, cardiac hypertrophy, and acute myocardial infarction, suggesting their pathophysiologic roles in these disorders. ANP and BNP exhibit diuretic, natriuretic, and vasodilatory activities via a guanylyl cyclase-coupled natriuretic peptide receptor subtype (guanylyl cyclase-A or GC-A). Here we report the generation of mice with targeted disruption of BNP (BNP-/- mice). We observed focal fibrotic lesions in ventricles from BNP-/- mice with a remarkable increase in ventricular mRNA expression of ANP, angiotensin converting enzyme (ACE), transforming growth factor (TGF)-beta3, and pro-alpha1(I) collagen [Col alpha1(I)], which are implicated in the generation and progression of ventricular fibrosis. Electron microscopic examination revealed supercontraction of sarcomeres and disorganized myofibrils in some ventricular myocytes from BNP-/- mice. No signs of cardiac hypertrophy and systemic hypertension were noted in BNP-/- mice. In response to acute cardiac pressure overload induced by aortic constriction, massive fibrotic lesions were found in all the BNP-/- mice examined, accompanied by further increase of mRNA expression of TGF-beta3 and Col alpha1(I). We postulate that BNP acts as a cardiocyte-derived antifibrotic factor in the ventricle.

Endothelin-1, endothelin-1 receptors and cardiac natriuretic peptides in failing human heart

Endothelin (ET)-1 is a potent vasoconstrictor peptide produced in the myocardium that can exert important effects on cardiac myocyte growth and phenotype; cardiac natriuretic peptides (ANP and BNP) are known to act as physiological antagonists of ET-1. In this study a comparative determination of ET-1 receptors and of the local productions of ET-1 and of ANP and BNP was made in different sites of failing and nonfailing hearts. Tissue from right and left atrium, right and left ventricle and interventricular septum from seven adult heart transplant recipients with end-stage idiopathic dilated cardiomyopathy (functional class III and IV, with ejection fraction < 35%) and from four post-mortem subjects without cardiac complications was analyzed. In failing hearts we observed a tendency to increase of density of binding sites, most evident in left ventricle (62.6 ± 22.6 fmol/mg protein vs. 29.0 ± 3.3, mean ± SEM, p = ns). A prevalence of ET-A subclass, observed in all samples, resulted more pronounced in failing hearts where this increase, found in all the cardiac regions, was more evident in left ventricle (p = 0.0007 vs nonfailing hearts). The local concentrations of ET-1, ANP and BNP resulted significantly increased in failing hearts with respect to controls in all sides of the heart. In failing hearts we have observed a tendency to increase in endothelin receptor density mainly due to a significant upregulation of ET-A subtype and a parallel increase of the tissue levels of ANP, BNP and ET-1 indicating an activation of these systems in heart failure.

Plasma and pericardial fluid natriuretic peptide levels in postinfarction ventricular dysfunction.

In the present study we examined plasma and pericardial fluid ANP and BNP concentrations in postinfarction ventricular dysfunction. The association of peptide levels to left ventricular (LV) dysfunction and to the localization of the myocardial infarction (MI) was studied. Plasma and pericardial fluid samples were obtained from 37 patients undergoing coronary bypass surgery. According to the ECG and preceding coronary angiography, the patients were divided into three groups: previous anterior myocardial infarction (MI) (n=12), previous inferior/posterior MI (n=15) and no history of MI (n=10). When compared to the control group with no MI, the patients with anterior MI had elevated plasma ANP and BNP (134+/-13 vs. 81+/-15 pg/ml, P<0.01 and 95+/-10 pg/ml vs. 26+/-8 pg/ml, P<0.01, respectively) and pericardial fluid BNP (473+/-60 pg/ml vs. 57+/-8 pg/ml, P<0.001) levels. The plasma natriuretic peptide concentrations were not increased in the patients with inferior/posterior MI, but the pericardial fluid BNP concentrations were greater than in the patients with no history of MI (129+/-35 pg/ml vs. 57+/-8 pg/ml, P<0.05). Six of the 12 patients with previous anterior MI had LVEF> or =45%. Despite their normal LV systolic function, these patients had increased plasma and pericardial fluid BNP levels when compared to the group with no history of MI (68+/-18 pg/ml vs. 26+/-8 pg/ml, P<0.05 and 534+/-258 pg/ml vs. 57+/-8 pg/ml, P<0.01, respectively). Previous anterior myocardial infarction was associated with increased cardiac BNP production even if the LV systolic function was normal (LVEF> or =45%). The high pericardial fluid BNP concentrations in postinfarction patients suggest that the BNP synthesis and release are augmented in the ventricular myocardium independent from the LVEF.

The Changes in Plasma Levels of Brain Natriuretic Peptide during Exercise in Patients With Ischemic Heart Disease

Background：Brain natriuretic peptide (BNP is primarily secreted from the cardiac ventricles. Circulating concentrations of BNP are known to be increased in established chronic heart failure and acute myocardial infarction and to correlate well with left ventricular dysfunction and prognosis. It may also act as an index of ischemic severity. This study was performed in order to evaluate the value of plasma BNP measurement during exercise tests in patients with ischemic heart disease for an assessment of myocardial ischemia. Method：This study included a total of 63 cases of suspected ischemic heart disease or myocardial infarction. The subjects underwent treadmill exercise with a modified Bruce protocol. Tc-99m MIBI (methoxyisobutyl Isonitrile SPECT image was obtained by one-day or two-day protocol with rest-stress sequence. They were divided into 3 groups by findings in exercise TC-99m MIBI SPECT；16 cases with reversible perfusion defect into the angina pectoris group, 12 cases with myocardial infarction and fixed perfusion defect into the myocardial infarction group and 35 cases without perfusion defect into the control group. Venous blood was obtained at rest and just after peak exercise. Plasma levels of BNP level were measured by radioimmunoassay. Result：BNP levels increased with exercise from 20.1±28.2 to 33.2±44.0 pg/ml in the control group, 33.9±48.8 to 44.6±49.2 pg/ml in the angina pectoris group and 86.6±85.0 to 140.9±116.2 pg/ml in the myocardial infarction group (p<0.01, respectively. BNP levels in the myocardial infarction group were significantly higher than those in the control and angina pectoris groups both at rest and after peak exercise (p<0.01, respectively. The changes in BNP levels with exercise were also significantly higher in the myocardial infarction group compared with those in the control and angina pectoris groups (p<0.01. The BNP levels at rest correlated significantly with the extent of perfusion defect and METs (r＝0.465, p<0.001；r＝-0.283, p<0.05, respectively. The BNP level following peak exercise correlated closely with the extent of perfusion defect and left ventricular ejection fraction (r＝ 0.481, p<0.001；r＝-0.301, p<0.05, respectively. The cha-nges in BNP level with exercise correlated well with the extent of perfusion defect and the ischemic severity (r＝0.352, p<0.01；r＝0.272, p<0.05, respectively. Conclusion：These findings suggest that the changes in BNP level during an exercise test could be used for an index of ischemic severity in patients with ischemic heart disease. (Korean Circulation J 2001;31( ( ( (7 :625-636

Clinical Use of Plasma BNP Concentrations for Diabetic Patients

Clinical Use of Plasma BNP Concentrations for Diabetic Patients

Opposite regulation of brain and C-type natriuretic peptides in the streptozotocin-diabetic cardiopathy.

C-type natriuretic peptide (CNP), a recent addition to the family of natriuretic peptides including atrial and brain natriuretic peptide (ANP, BNP), is believed to be an endothelium-derived vasodilator and to have an antimitotic effect. ANP and BNP concentrations are increased in conditions such as congestive heart failure, but cardiac CNP concentrations have not been investigated in this connection. Diabetes mellitus also involves myocardial dysfunctions without coronary artery disease or systemic hypertension. We therefore investigated the cardiac expression of CNP mRNA compared with that of BNP mRNA in streptozotocin (STZ)-diabetic rats. STZ- diabetic male Wistar rats (n=6) were studied in comparison with controls (n=6). The animals were characterised by their mean arterial blood pressure and plasma glucose concentrations. After extraction of total cardiac RNA, a specific cDNA probe of BNP was used for northern blot analysis, whereas myocardial CNP expression was analysed by an RNase-protection assay. Twelve weeks after diabetes was induced, the rats were normotensive (96.4+/-2.0 compared with 95.1+/-1.9 mmHg) and hyperglycaemic (615+/-61 compared with 165+/-21 mg/dl; P<0.001). Left ventricular pressure was significantly impaired (76.8+/-6.4 compared with 51.2+/-3.6 mmHg). STZ-diabetic rats had a 3.2-fold increase in cardiac BNP expression compared with controls. In contrast, cardiac CNP mRNA concentrations were decreased 2.6-fold. CNP seems to be downregulated like other peptides with antimitotic and vasodilator activities (nitric oxide, prostacyclin, kinins). This may contribute to cardiac dysfunction in diabetes mellitus and suggests that stimulation of CNP expression could provide cardiac protection in such cases.

Plasma concentrations of atrial and brain natriuretic peptides and cyclic guanosine monophosphate in response to dobutamine infusion in patients with surgically repaired tetralogy of fallot.

We examined the plasma concentrations of atrial and brain natriuretic peptides (ANP and BNP) and cyclic guanosine monophosphate (cGMP) during dobutamine infusion and their relationship with hemodynamic parameters in 14 patients with surgically repaired tetralogy of Fallot (TOF). Dobutamine was infused at an initial dose of 5 microgram/kg/min and increased by 5 microgram/kg/min up to 20 microgram/kg/min. The plasma ANP, BNP, and cGMP concentrations were determined before infusion, at the end of each stage, and 15 minutes after discontinuing dobutamine infusion. The plasma concentrations of ANP, BNP, and cGMP were elevated in all patients before dobutamine infusion. The ANP, BNP, and cGMP concentrations decreased in 11 of the 14 patients during dobutamine infusion. In contrast, the plasma ANP and BNP concentrations increased in the remaining 3 patients without a change in the cGMP concentration. The right ventricular pressure and volume were significantly elevated in these patients. The plasma cGMP concentration correlated with the ANP concentration (r = 0.62, p < 0.01) but not the BNP concentration. The plasma ANP concentration during dobutamine infusion correlated with right ventricular systolic pressure (r = 0.71, p < 0.05), mean right atrial pressure (r = 0.29, p < 0.05), and mean pulmonary capillary wedge pressure (r = 0.32, p < 0.05). The BNP concentration correlated with right ventricular volume (r = 0.61, p < 0.05) and systolic pressure (r = 0. 46, p < 0.05). In conclusion, rapid changes in ANP, BNP, and cGMP concentrations during dobutamine infusion reflect the changes in atrial and ventricle pressure and volume overload. In surgically repaired TOF, the ANP concentration is affected by right ventricular systolic pressure, right atrial pressure, and pulmonary capillary pressure. Furthermore, the BNP concentration reflects right ventricular pressure and volume overload.

Neuropeptide secretion in exercise

Plasma concentrations of atrial natriuretic peptide immunoreactivity (irANP) and brain natriuretic peptide immunoreactivity (irBNP) in elderly normal subjects (mean age 71.1, range 66–81 years, n = 10) were examined before (rest), during (peak of exercise) and after (3 min, 6 min) a treadmill exercise test (modified Bruce protocol). An attempt was also made to determine the effect of steady state exercise (30% and 50%) and posture (supine, sitting) on circulating levels of atrial natriuretic peptide and calcitonin gene-related peptide (CGRP) in man. The results suggest that exercise gives rise to increased levels of irANP and irCGRP, but not human BNP. The study also demonstrated a > 40% rise in irCGRP and irANP levels at 50% steady state exercise compared with 30% steady state exercise. irCGRP was shown to decline in the upright position compared with the supine position, and irCGRP did not rise with exercise. Although ANP is normally stored in large concentration in the atria with much less in the ventricles and BNP is derived to a much greater extent from the ventricles, the differential release rate of these peptides may make BNP concentration a more sensitive indicator of left ventricular dysfunction than ANP. The observations obtained here also raise the possibility that the ANP system may not only help to eliminate intermittent overhydration, but also participate in the postural regulation of diuresis and natriuresis and perhaps even support the maintenance of excretory kidney function in the ageing subjects.

Plasma BNP Concentration Is the Most Sensitive Marker for Management of Chronic Congestive Heart Failure

Plasma BNP Concentration Is the Most Sensitive Marker for Management of Chronic Congestive Heart Failure