Secretion Of BNP Research Articles

Effects of altered body fluid balance and high blood pressure on the plasma brain natriuretic peptide in rats.

The present study was aimed to investigate the regulatory mechanisms of BNP release. Effects of acute and chronic perturbations in body fluid balance, changes in BP, and regulatory roles of NO and endothelin systems on BNP release were examined in rats. Although acute extracellular volume expansion did not have significant effects on plasma BNP, prolonged high-salt intake increased plasma BNP levels. Plasma BNP levels were also higher in 2K1C rats compared with the control. Although infusion of L-NAME increased the plasma BNP in control, it did not further affect the plasma BNP in rats with high-salt intake. Although L-arginine (20 mg.kg-1 per min) per se did not have significant effects on plasma BNP, it blocked the stimulatory effect of L-NAME (200 micrograms.kg-1 per min). Plasma BNP was severalfold increased following a single injection of endothelin (0.3 micrograms/kg) in normal and high-salt intake groups, the magnitude of which was not significantly affected by the high-salt intake. Although indomethacin did not have significant effects on plasma BNP in normal rats, it blocked the stimulatory effect of 2K1C hypertension. It is concluded that BNP is regulated by chronic changes in body fluid balance and blood pressure. It is also suggested that endothelin and NO systems may directly regulate the secretion of BNP in vivo. An endogenous prostaglandin synthesis may be involved in the stimulated release of BNP in hypertension.

Roles of natriuretic peptides in heart failure

In the present study, using in vitro experimental models, we analyzed the synthesis and secretion of ANP and BNP in normal and failing hearts, and examined the mechanism of the augmented expression of ANP and BNP genes in the failing heart.

Brain natriuretic peptide as a novel cardiac hormone in humans. Evidence for an exquisite dual natriuretic peptide system, atrial natriuretic peptide and brain natriuretic peptide.

Using a specific radioimmunoassay for human brain natriuretic peptide (hBNP) with a monoclonal antibody, we have investigated its synthesis, secretion, and clearance in comparison with those of atrial natriuretic peptide (ANP) in normal subjects and patients with congestive heart failure (CHF). Mean BNP-like immunoreactivity (-LI) levels in normal atrium and ventricle were 250 and 18 pmol/g, respectively. The plasma BNP-LI level in normal subjects was 0.90 +/- 0.07 fmol/ml, which was 16% of the ANP-LI level. In contrast, the plasma BNP-LI level markedly increased in patients with CHF in proportion to its severity, and surpassed the ANP-LI level in severe cases. There was a significant step-up of the plasma BNP-LI level in the coronary sinus (CS) compared with that in the aortic root (Ao) and the difference between these BNP-LI levels, delta(CS-Ao)BNP, also increased with the severity of CHF. In addition, the step-up of the BNP-LI level in the anterior interventricular vein [delta(AIV-Ao)BNP] was comparable to delta(CS-Ao)BNP, indicating that BNP is secreted mainly from the ventricle. Predominant BNP synthesis in the ventricle was also confirmed by Northern blot analysis. Catheterization and pharmacokinetic studies revealed that hBNP is cleared from the circulation more slowly than alpha-hANP; this was in part attributed to lower (about 7%) binding affinity of hBNP to clearance receptors than that of alpha-hANP. A predominant molecular form of BNP-LI in the heart and plasma was a 3-kD form corresponding to hBNP. These results indicate that BNP is a novel cardiac hormone secreted predominantly from the ventricle, and that the synthesis, secretion and clearance of BNP differ from those of ANP, suggesting discrete physiological and pathophysiological roles of BNP in a dual natriuretic peptide system.

Increased secretion of brain natriuretic peptide and atrial natriuretic peptide, but not sufficient to induce natriuresis in rats with nephrotic syndrome

The levels of immunoreactive brain natriuretic peptide (ir-BNP) and immunoreactive atrial natriuretic peptide (ir-ANP) were evaluated by radioimmunoassay in both the atrium, ventricle and plasma of adriamycin-induced nephrotic rats and control rats. There was no difference in right and left atrial concentrations of ir-BNP, however, a higher right atrial concentration of ir-ANP was observed in nephrotic rats than in controls (p < 0.01). The ventricular ir-BNP and ir-ANP were increased in nephrotic rats compared to controls (BNP: p < 0.001, ANP: p < 0.001). Cardiac BNPs were composed of pro-BNP (γ-BNP) and its C-terminal 45-amino-acid peptide (BNP-45). The ratio of BNP-45 γ- BNP in nephrotic rats was higher than that of controls in both atria and in the ventricle. Plasma ir-BNP and ir-ANP were significantly higher in nephrotic rats than in controls (BNP: p < 0.001, ANP: p < 0.001), and each level was negatively correlated with urinary sodium excretion in nephrotic rats (BNP: r = −0.84, p < 0.001, ANP: r = −0.88, p < 0.001). These results suggest that production and secretion of both BNP and ANP are concomitantly stimulated by a decreased renal ability to eliminate sodium and water, but this secretion is insufficient to induce effective natriuresis in nephrotic rats.

Diagnostic Role of NT Pro BNP in Diabetes Type 2 Patients Associated with Cardiovascular Disease Risk, A Study from Central India

Cardiovascular disease is the most frequent cause of death in patient with diabetes. It is difficult to evaluate cardiovascular status of patients with diabetes because of complex symptomatology. NTproBNP, a split peptide from pro BNP molecule is a novel biomarker, released from cardiac myocytes in response to myocardial stretch, cardio vascular disease, endothelial dysfunction and heart failure. We aimed to test that is elevated NTproBNP levels associated with increased risk of cardiovascular disease in diabetes patients in comparison to matched control. Demographic, anthropometric measure, NT pro BNP, lipid profile, blood glucose were estimated and compared among angiographically proven cardiovascular disease patients with diabetes and healthy controls. Univariate and multivariate analysis were carried out to compare individual factor using t-Test, ANOVA and the inter group comparisons were done by using Bon ferroni Post Hoc test. Patients with type 2 diabetes were shown to have higher NTproBNP values (n=50, 1481.021±813.405) than control subjects (n=50, 23.562±23.395) (p &lt;0.05). NTproBNP levels were independently related to diabetes after adjustment for age, sex, family history, smoking, obesity, blood pressure and lipid profile. Our data suggests that the secretion of NT pro BNP is increased in type II diabetes patients, suggesting association of diabetes and NTproBNP in cardio vascular disease with higher prevalence. Thus NTproBNP may serve as a screening tool to diagnose patients with type II diabetes with cardiovascular disease having complex symptomatology. Keyword: NTproBNP, Cardiovascular disease, Diabetes DOI:10.3329/jom.v11i1.4266 J Medicine 2010: 11: 33-38