DIRECT VASODILATOR EFFECT OF MILRINONE, AN INOTROPIC DRUG, ON ARTERIAL CORONARY-BYPASS GRAFTS

Citation
Jj. Liu et al., DIRECT VASODILATOR EFFECT OF MILRINONE, AN INOTROPIC DRUG, ON ARTERIAL CORONARY-BYPASS GRAFTS, Journal of thoracic and cardiovascular surgery, 113(1), 1997, pp. 108-113
Citations number
14
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Cardiac & Cardiovascular System",Surgery
ISSN journal
0022-5223
Volume
113
Issue
1
Year of publication
1997
Pages
108 - 113
Database
ISI
SICI code
0022-5223(1997)113:1<108:DVEOMA>2.0.ZU;2-Q
Abstract
Milrinone is an inotropic drug with vasodilator activity that has been shown to be useful in increasing cardiac output and decreasing wedge pressure, Despite these advantages, it is unknown. whether this drug c an be used for the treatment of perioperative spasm of coronary bypass grafts, This study was undertaken to investigate the in vitro vascula r effect of milrinone on internal thoracic arteries obtained from pati ents undergoing coronary artery bypass grafting, The results showed th at milrinone produced a potent, concentration-dependent, preventive ef fect on the norepinephrine-induced contraction of internal thoracic ar teries, as well as reversing contraction of internal thoracic arteries by receptor-dependent agents, including the thromboxane A(2) mimetic U46619, the vasoconstrictor peptide endothelin-1, and the alpha(1)-adr enal receptor agonist phenylephrine, The relaxing effect of milrinone was weaker, however, on internal thoracic arteries contracted with 25 mmol/L potassium chloride, Comparison of milrinone with other vasodila tors, including papaverine, nitroprusside, and glyceryl trinitrate, sh owed milrinone to be more potent than papaverine but less potent than nitroprusside and glyceryl trinitrate, The inhibitory effect of milrin one on internal thoracic artery contraction appeared as a reduction in contractile force, not as an increase in the values of concentrations of the agonists causing 50% maximal contraction, which indicates that milrinone exerts its vasodilator effect directly on the smooth muscle s, not on the membrane receptors. The results also showed no significa nt difference in relaxing effect between internal thoracic artery ring s with and without endothelium. In conclusion, this study provides exp erimental evidence that milrinone is a potent, endothelium-independent , direct vasodilator of the human internal thoracic artery and provide s the scientific rationale for a future clinical trial with this drug for the perioperative treatment of internal thoracic artery spasm in c ardiac surgical patients.