Regional distribution of immunoreactive brain natriuretic peptide in porcine brain and spinal cord

In order to elucidate the physiological functions of brain natriuretic peptide (BNP), radioimmunoassay for BNP was established and regional distribution of BNP in porcine brain and spinal cord was investigated. The concentration of immunoreactive (ir-) BNP in porcine whole brain was estimated to be 0.63 pmol/g, 13 times higher than that of ir-atrial natriuretic peptide (ANP). Highest concentrations of ir-BNP were found in the medulla-pons, striatum, and spinal cord. Medium concentration was noted in the hypothalamus. This distribution of ir-BNP in porcine brain was found to be different from that of ir-ANP simultaneously measured. Furthermore, BNP and BNP-32 were identified as two major forms of ir-BNP in porcine brain.