[Changes and cardiac protective effects of adrenomedullin during myocardial ischemia-reperfusion period].
OBJECTIVE
To investigate if adrenomedullin (Adm) is concerned with cardiac ischemia-reperfusion (I/R) process and to study its effects on I/R injury.


METHODS
Plasma Adm dynamic levels were tested in 17 patients with acute myocardial infarction (AMI), who had got successful blood reperfusion through intravenous thrombolytic therapy. The indices of I/R injury were measured in I/R models of isolated perfused rat heart when Adm (10(-7) mol/L) was given in reperfusion period.


RESULTS
Plasma Adm concentrations before thrombolytic therapy in AMI patients were significantly higher than those of control group (3.8 pmol/L +/- 0.8 pmol/L vs 1.9 pmol/L +/- 0.8 pmol/L P < 0.01), and rose further after successful thrombolytic therapy, which resulted in efficient myocardial reperfusion. The peak level of plasma Adm, which appeared 4 hours after thrombolytic therapy, was 42.9% higher than that before therapy. The levels began to decrease and dropped to the levels before therapy at 12 and 24 hours after thrombolysis, respectively. In isolated perfused rat heart models, when Adm (10(-7) mol/L) was added in perfusion fluid for 15 minutes reperfusion after 45 minutes ischemic period, +/-LVdp/dt max of the heart increased 76.9% and 67.9%, and the average volume of coronary efflux increased 48.8%, respectively, compared with that of control group of ischemia-reperfusion. The amount of total protein, myoglobin and activities of LDH in effluent samples of Adm group were 34.3%, 63.6% and 29.2% lower than those of control group, respectively.


CONCLUSIONS
Plasma Adm concentrations in AMI patients increase significantly during myocardiac reperfusion period after thrombolytic therapy. To some extent, Adm may have myocardial protective effects during ischemia-reperfusion period.
Cao
J
J
Department of Cardiology, The First Hospital, Beijing Medical University, Beijing 100034, China.
Zhang
J
J
Wang
X
X
D053607:Adrenomedullin; D000328:Adult; D000368:Aged; D000818:Animals; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D015425:Myocardial Reperfusion; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000503:physiopathology / Q000517:prevention & control*; D010455:Peptides / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D002316:Cardiotonic Agents; D010455:Peptides; D053607:Adrenomedullin