natriuretic-peptide--brain and Nephrotic-Syndrome

Cardiac involvement occurs in up to 50% of patients with primary or A amyloidosis (ALA) and is associated with very poor prognosis. B-type natriuretic peptide (BNP) has been proposed as a guide for treatment of heart failure patients and as an index of myocardial dysfunction in patients with ALA. Data about BNP dosage for cardiovascular monitoring of patients with ALA on renal replacement therapy are lacking.. A 64 year old Caucasian man was admitted because of nephrotic syndrome in July 2003. Renal diagnosis was ALA. Melphalan and prednisolone were given but renal function worsened and in April 2004 standard bicarbonate hemodialysis was started. In March 2004 thalidomide was added to his therapy. During the follow-up ejection fraction was stable and was 65% on the contrary E/A ratio gradually increased and overtook 1. BNP plasma levels were increased and the values recorded during the follow-up were: 2505 pg/mL in October 2003 (normal reference values<100), 1827 in April 2004, 4006 in June 2004, 5000 in September 2004, 3750 in January 2005 and 1920 in April 2005. In September 2005 BNP was 3380 pg/mL. The patient was still alive after a follow-up longer than two years.. In ALA patients a powerful prognostic role of BNP has been reported whose expression is increased in ventricular myocytes of patients with cardiac involvement. BNP level monitoring does not appear to be superior to standard echocardiography in evaluating cardiovascular status of uremic patients with ALA.

Topics: Amyloidosis; Anti-Inflammatory Agents; Bicarbonates; Buffers; Cardiac Output, Low; Follow-Up Studies; Humans; Immunosuppressive Agents; Kidney Diseases; Male; Melphalan; Middle Aged; Natriuretic Peptide, Brain; Nephrotic Syndrome; Prednisolone; Renal Dialysis; Thalidomide; Treatment Outcome

The major metabolic change that characterizes nephrotic syndrome (NS) is hypoalbuminemia. Edema, which is a well-recognized clinical feature, often results in disorder of peripheral circulation and congestive heart failure. We previously reported that the albumin content of kidney lysosomal proteins was increased more than ten-fold in nephrotic rats compared to control rats, suggesting that kidney lysosomes play an important role in protein degradation in NS. The present study was carried out to elucidate the role of catabolism of BNP, which is one of the functional protein-natriuretic peptides. We injected puromysin aminonucleoside(PAN) to induce the nephrotic rat state and isolated kidney lysosomes from normal and nephrotic rat kidney cortex by our methods. Immunoblot analysis of tricine-SDS polyacrylamide gel electrophoresis of rat kidney lysosomal proteins revealed the presence of an immuno-reactive peptide band, corresponding to the endogenous BNP. In addition, this was reduced as compared with the normal control. These result suggest that kidney lysosomes play an important role in BNP metabolism to maintain body fluid homeostasis and regulate blood pressure levels.

Topics: Animals; Kidney; Lysosomes; Male; Natriuretic Peptide, Brain; Nephrotic Syndrome; Rats; Rats, Wistar

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 less than 0.01). The ventricular ir-BNP and ir-ANP were increased in nephrotic rats compared to controls (BNP: p less than 0.001, ANP: p less than 0.001). Cardiac BNPs were composed of pro-BNP (gamma-BNP) and its C-terminal 45-amino-acid peptide (BNP-45). The ratio of BNP-45/gamma-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 less than 0.001, ANP: p less than 0.001), and each level was negatively correlated with urinary sodium excretion in nephrotic rats (BNP: r = -0.84, p less than 0.001, ANP: r = -0.88, p less than 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.

Topics: Animals; Atrial Natriuretic Factor; Doxorubicin; Heart Atria; Heart Ventricles; Male; Natriuresis; Natriuretic Peptide, Brain; Nephrotic Syndrome; Nerve Tissue Proteins; Rats; Rats, Inbred Strains; Sodium