2,3-Butanedione monoxime preserves coronary artery endothelium-dependent relaxation during myocardial ischemia in the isolated rat heart.
OBJECTIVE
To evaluate the potential benefit of 2,3-butanedione monoxime (BDM) in preserving endothelium-dependent coronary artery relaxation during myocardial ischemia.


METHODS
Langendorff-perfused rat heart model. Endothelium-dependent and independent relaxations were tested with infusion of 5-hydroxytryptamine (10(-6) mol/L) and sodium nitroprusside (10(-5) mol/L), respectively. Four groups of hearts (n = 6) were used. Group 1 was perfused with BDM (25 mmol/L) without ischemia for 30 mins. Group 2 was perfused for 10 mins with BDM and exposed to 30 mins of no flow ischemia (37 degrees C). Group 3 was perfused with cold (4 degrees C) nonoxygenated BDM (30 mins) and group 4 (control) was exposed to 30 mins of no flow ischemia alone. Left ventricular pressure (LVP), left ventricular pressure first derivative (dP/dt) and coronary basal flow were evaluated before treatment and after 30 mins of reperfusion.


RESULTS
BDM perfusion alone (group 1) did not affect coronary reactivity. Preservation of endothelium-dependent and -independent relaxation was significantly enhanced after ischemia in groups 2 and 3 (BDM-treated) compared with group 4 (control). No significant benefit was found regarding LVP and dP/dt in all groups. Postreperfusion coronary flow was decreased in all hearts except the controls (group 4), suggesting a residual BDM intrinsic effect on coronary flow.


CONCLUSIONS
These experiments suggest that BDM can enhance preservation of coronary artery endothelium-dependent and -independent relaxation during myocardial ischemia in the isolated rat heart.
Cartier
R
R
Department of Cardiovascular Surgery, Montreal Heart Institute, Quebec.
Carrier
M
M
Buluran
J
J
Millette
D
D
Dagenais
F
F
D000818:Animals; D003331:Coronary Vessels / Q000187:drug effects*; D003931:Diacetyl / Q000494:pharmacology*; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D017202:Myocardial Ischemia / Q000188:drug therapy*; D009569:Nitric Oxide / Q000494:pharmacology*; D051381:Rats
D009569:Nitric Oxide; D003931:Diacetyl