Glibenclamide blunts coronary flow reserve induced by adenosine and dipyridamole.
OBJECTIVE
A reduced coronary flow reserve is considered indicative of significant coronary stenosis. As experimental data suggest that adenosine and dipyridamole induce vasodilatation by opening of ATP-sensitive potassium channels, we sought to determine the effect of glibenclamide, an antidiabetic blocker of ATP-sensitive potassium channels, on adenosine- and dipyridamole-induced coronary flow reserve.


METHODS
Coronary flow velocities were measured in 15 pigs using a Doppler flow wire. The effect of increasing glibenclamide concentrations (0.1-10 microM) on adenosine-induced coronary flow reserve was examined in five animals. Ten pigs served as time controls. The time controls were subsequently treated by 3 microM glibenclamide (n = 5) or corresponding vehicle (n = 5) and the flow response to 0.56 mg/kg dipyridamole determined.


RESULTS
Glibenclamide elicited a concentration-dependent inhibition of adenosine-induced coronary flow reserve, reaching significance at glibenclamide concentrations of 3 and 10 microM. The coronary flow reserve stimulated by dipyridamole was reduced significantly by 3 microM glibenclamide.


CONCLUSIONS
Glibenclamide blunts coronary flow reserve stimulated by adenosine and dipyridamole. This interaction may have clinical implications in diabetics undergoing adenosine- or dipyridamole-dependent diagnostic procedures.
Mortensen
Ulrik Markus
UM
Department of Cardiology, Aarhus University Hospital (Skejby), Aarhus N, Denmark. ulrik.mortensen@iekf.au.dk
Nielsen-Kudsk
Jens Erik
JE
Jakobsen
Preben
P
Nielsen
Torsten Toftegaard
TT
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D003326:Coronary Circulation / Q000187:drug effects*; D004347:Drug Interactions; D005905:Glyburide / Q000494:pharmacology*; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects*; D012039:Regional Blood Flow / Q000187:drug effects*; D013552:Swine; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology*
D007004:Hypoglycemic Agents; D015221:Potassium Channels; D014665:Vasodilator Agents; D000241:Adenosine; D005905:Glyburide