Characterization of immunoreactive brain natriuretic peptide in human cardiac atrium.
Based on cDNA sequence data for human brain natriuretic peptide (BNP) precursor (1), a radioimmunoassay (RIA) system highly specific to human BNP (hBNP) was developed and used to characterize immunoreactive (ir-) hBNP in cardiac atrium. Gel filtration of ir-hBNP in atrium indicated that ir-hBNP was mainly comprised of two molecular forms of 13-15K and 4K. In reverse phase high performance liquid chromatography (HPLC), the low molecular weight (MW) ir-hBNP emerged as a single peak at an elution time identical to that of synthetic hBNP-32. The high MW ir-hBNP was also eluted as a single peak. On the other hand, tissue concentrations of ir-hBNP in cardiac atria were found to be 9.98-593.22 pmol/g in 13 specimens, being about 1/150 the concentration of ir-human atrial natriuretic peptide (hANP). These results demonstrate that hBNP is present as a peptide in human heart, suggesting that hBNP is secreted from heart and functions together with hANP as a hormone.
Tateyama
H
H
Department of Biochemistry, Miyazaki Medical College, Japan.
Hino
J
J
Minamino
N
N
Kangawa
K
K
Ogihara
T
T
Matsuo
H
H
D000328:Adult; D000368:Aged; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006325:Heart Atria / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009206:Myocardium / Q000032:analysis*; D020097:Natriuretic Peptide, Brain; D009369:Neoplasms / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000032:analysis* / Q000138:chemical synthesis / Q000302:isolation & purification; D011863:Radioimmunoassay
D009419:Nerve Tissue Proteins; D020097:Natriuretic Peptide, Brain