title: Glibenclamide blunts coronary flow reserve induced by adenosine and dipyridamole.
abstract: 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.
authors.affiliation: Department of Cardiology, Aarhus University Hospital (Skejby), Aarhus N, Denmark. ulrik.mortensen@iekf.au.dk
authors.forename: Ulrik Markus
authors.initials: UM
authors.lastname: Mortensen
authors.forename: Jens Erik
authors.initials: JE
authors.lastname: Nielsen-Kudsk
authors.forename: Preben
authors.initials: P
authors.lastname: Jakobsen
authors.forename: Torsten Toftegaard
authors.initials: TT
authors.lastname: Nielsen
mesh_terms: 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*
chemical_list: D007004:Hypoglycemic Agents; D015221:Potassium Channels; D014665:Vasodilator Agents; D000241:Adenosine; D005905:Glyburide