Brain natriuretic peptide is a novel cardiac hormone.
Using a radioimmunoassay for brain natriuretic peptide (BNP), we have measured levels of BNP-like immunoreactivity (-LI) in extract of the porcine heart, in perfusate from the isolated porcine heart and in porcine plasma. BNP-LI was detected in the extract of the atrium, though no detectable amount of BNP-LI (more than 1 ng/g) was present in the ventricle. The BNP-LI level in the porcine atrium was 148.7 +/- 23.3 ng/g. BNP-LI was also detected in the perfusate from the heart. Basal secretory rate of BNP was 3.18 +/- 0.76 ng/min. Moreover, BNP-LI was detected in porcine plasma at the concentration of 4.2 +/- 1.3 pg/ml. Gel filtration studies showed that BNP is present in the atrium as a large molecule and is secreted into the circulation as a small molecule. The percentage of BNP-LI to atrial natriuretic peptide (ANP)-LI was almost the same among the extract, the perfusate and the plasma (2-3 percent). These results indicate that BNP is synthesized in and is secreted into the circulation from the heat in a similar fashion as ANP.
Saito
Y
Y
Department of Medicine, Kyoto University School of Medicine, Japan.
Nakao
K
K
Itoh
H
H
Yamada
T
T
Mukoyama
M
M
Arai
H
H
Hosoda
K
K
Shirakami
G
G
Suga
S
S
Minamino
N
N
D000818:Animals; D016275:Atrial Function; D009320:Atrial Natriuretic Factor / Q000032:analysis; D006321:Heart / Q000502:physiology*; D020097:Natriuretic Peptide, Brain; D009419:Nerve Tissue Proteins / Q000502:physiology*; D011863:Radioimmunoassay; D013552:Swine
D009419:Nerve Tissue Proteins; D020097:Natriuretic Peptide, Brain; D009320:Atrial Natriuretic Factor