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 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.
Yokota
N
N
First Department of Internal Medicine, Miyazaki Medical College, Japan.
Yamamoto
Y
Y
Aburaya
M
M
Kitamura
K
K
Eto
T
T
Kangawa
K
K
Minamino
N
N
Matsuo
H
H
Tanaka
K
K
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D004317:Doxorubicin; D006325:Heart Atria / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D008297:Male; D009318:Natriuresis; D020097:Natriuretic Peptide, Brain; D009404:Nephrotic Syndrome / Q000139:chemically induced / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine
D009419:Nerve Tissue Proteins; D020097:Natriuretic Peptide, Brain; D004317:Doxorubicin; D009320:Atrial Natriuretic Factor; D012964:Sodium