Distribution and characterization of rat immunoreactive proadrenomedullin N-terminal 20 peptide (PAMP) and the augmented cardiac PAMP in spontaneously hypertensive rat.
Proadrenomedullin N-terminal 20 peptide (PAMP) is a novel hypotensive peptide processed from an adrenomedullin precursor. In this study, high concentrations of immunoreactive PAMP (ir-PAMP) were detected in rat cardiac atrium and adrenal gland by the radioimmunoassay (RIA) for rat PAMP. The mean plasma concentration of rat ir-PAMP was 3.8 +/- 0.3 fmol/ml. Analysis in atrium, adrenal gland and plasma with high performance liquid chromatographies showed that most ir-PAMP emerged as one major peak at the position exactly identical to that of the authentic rat PAMP. We further investigated the tissue and plasma concentrations of rat ir-PAMP in spontaneously hypertensive rat (SHR) to elucidate the role of PAMP in hypertension. The ir-PAMP concentration in heart tissue of SHR was found to be increased compared with that of the control rat. Especially, the atrial concentration of ir-PAMP of SHR (5.66 +/- 0.78 fmol/mg wet tissue) was significantly higher than that of the control (3.29 +/- 0.22 fmol/mg wet tissue). Cardiac PAMP might have a role for the protection from systemic hypertension.
Inatsu
H
H
First Department of Internal Medicine, Miyazaki Medical College, Japan.
Sakata
J
J
Shimokubo
T
T
Kitani
M
M
Nishizono
M
M
Washimine
H
H
Kitamura
K
K
Kangawa
K
K
Matsuo
H
H
Eto
T
T
D000311:Adrenal Glands / Q000737:chemistry*; D053607:Adrenomedullin; D000595:Amino Acid Sequence; D000818:Animals; D006325:Heart Atria / Q000737:chemistry*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010446:Peptide Fragments / Q000032:analysis* / Q000138:chemical synthesis; D010455:Peptides; D011506:Proteins / Q000032:analysis* / Q000138:chemical synthesis; D011863:Radioimmunoassay / Q000379:methods*; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D012680:Sensitivity and Specificity
D010446:Peptide Fragments; D010455:Peptides; D011506:Proteins; D053607:Adrenomedullin