Up-regulated synthesis of mature-type adrenomedullin in coronary circulation immediately after reperfusion in patients with anterior acute myocardial infarction.
OBJECTIVE
Levels of adrenomedullin (AM), a potent vasodilatory peptide, have been shown to increase in the early stage of acute myocardial infarction (AMI). The purpose of this study was to determine whether coronary sinus-aortic step-up of mature forms of AM is accelerated in patients with AMI after reperfusion.


METHODS
The subjects were 29 consecutive patients with a first episode of anterior AMI and 10 normal controls. All patients with AMI underwent balloon reperfusion therapy within 24 h after symptom onset. Plasma levels of two molecular forms of AM (an active, mature form [AM-m] and an intermediate, inactive glycine-extended form [AM-Gly]) in the aorta and coronary sinus (CS) were measured by specific immunoradiometric assay after reperfusion.


RESULTS
Plasma levels of AM-m and AM-Gly in the aorta and CS were higher in AMI patients than in controls. CS-aortic step-up of AM-m, which is an index of myocardial production of AM-m, was significantly greater in AMI patients than in controls (1.7 +/- 1.4 vs. 0.4 +/- 0.3 pmol/L, P < 0.01). However, there was no significant difference in CS-aortic step-up of AM-Gly (P = 0.30). AMI patients with left ventricular dysfunction (n = 10) had a significantly higher CS-aortic AM-m step-up than AMI patients without left ventricular dysfunction (n = 19). AM-m in the aorta and CS negatively correlated with the left ventricular ejection fraction (r = -0.50, r = -0.48, P < 0.01).


CONCLUSIONS
Myocardial synthesis of AM-m is accelerated in patients with reperfused AMI, especially in patients with critical left ventricular dysfunction. Increased myocardial synthesis of active AM may protect against cardiac dysfunction, myocardial remodeling, or both after the onset of AMI.
Yasu
Takanori
T
Department of Integrated Medicine I, Omiya Medical Center, Jichi Medical School, Saitama, Saitama, 330-8503 Japan.
Nishikimi
Toshio
T
Kobayashi
Nobuhiko
N
Ikeda
Nahoko
N
Ueba
Hiroto
H
Nakamura
Tomohiro
T
Funayama
Hiroshi
H
Kubo
Norifumi
N
Kawakami
Masanobu
M
Matsuoka
Hiroaki
H
Kangawa
Kenji
K
Saito
Muneyasu
M
D053607:Adrenomedullin; D000368:Aged; D003326:Coronary Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood* / Q000150:complications / Q000628:therapy; D015425:Myocardial Reperfusion; D010455:Peptides / Q000097:blood*; D015854:Up-Regulation; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000150:complications
D010455:Peptides; D053607:Adrenomedullin