ISSN : 1301-5680
e-ISSN : 2149-8156
Turkish Journal of Thoracic and Cardiovascular Surgery     
Intermedin (IMD/AM2) dilates the pig coronary vascular bed through release of nitric oxide
Suat Doğancı1, Vedat Yıldırım2, Cengiz Bolcal1, Ufuk Demirkılıç1, Ertuğrul Özal1, Elvin Akdağ3, Mehmet Arslan1, Bülent Gümüşel4, Howard Lippton5
1Departments of Cardiovascular Surgery, Gülhane Military Medical School, Ankara
2Departments of Anesthesiology and Reanimation, Gülhane Military Medical School, Ankara
3Departments of Medical Pharmacology, Gülhane Military Medical School, Ankara
4Department of Pharmacology, Hacettepe University, Faculty of Pharmacy, Ankara
5Pneumosite, LLC, Shreveport, USA
DOI : 10.5606/tgkdc.dergisi.2011.020
Background: This study investigated the effects of intermedin/ adrenomedullin-2 (IMD/AM2), an endogenous agonist for calcitonin-like calcitonin receptors, on coronary and systemic hemodynamics.

Methods: Ultrasonic transit time flow probes were placed around the left anterior descending (LAD) artery in the anesthetized, open-chest pig (n=6). A catheter was placed into the proximal LAD. Intracoronary arterial bolus injections of IMD, adrenomedullin (hADM13-52) and calcitonin gene related peptide (CGRP) (1, 3, 10 μg) were performed and the changes in the velocity of coronary blood flows were continuously recorded.

Results: Intracoronary artery bolus injections of IMD, hADM13-52 and CGRP increased coronary blood flow in a dose-dependent manner. At the studied doses, IMD was more potent than CGRP and hADM13-52 and did not alter systemic arterial pressure, cardiac output and cardiac index. Intracoronary artery injection of NG-Nitro-Larginine- methyl ester (L-NAME) significantly decreased the coronary vasodilator response (CVR) to IMD.

Conclusion: The present data suggest that IMD possesses marked vasodilator activity in the pig coronary vascular bed. The present data further suggest that IMD acts on a receptor in the coronary vascular bed that is coupled to endothelial nitric oxide release. The degree of the CVR to IMD may serve as functional marker for the integrity of endothelial cells in resistance segments of the coronary circulation

Keywords : Coronary vascular bed; intermedin; nitric oxide; vasodilatation
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