Influence of ATP-sensitive potassium channel blocker on hypoxia-induced damage of isolated guinea pig heart.
1. Isolated guinea pig hearts were perfused under constant flow conditions with Krebs-Henseleit buffer. Hearts were subjected to 15 min of hypoxia followed by reoxygenation in the presence and in the absence of 100 microns glyburide, an ATP-sensitive potassium channel blocker. Heart rate, left ventricular pressure and lactate dehydrogenase (LDH) release were measured at 5 min intervals. 2. Small decreases in heart rate and left ventricular pressure were observed during glyburide infusion with hypoxia, however LDH release, which was used as an index of cellular damage, was dramatically elevated. 3. Neither glyburide, nor the vehicle in which it was dissolved, appeared to produce myocardial damage under normoxic conditions. 4. It is concluded that ATP-sensitive potassium channels are important in the protection of the myocardium during hypoxia in isolated guinea pig hearts perfused under constant flow conditions.
McKean
T A
TA
Department of Biological Sciences, University of Idaho, Moscow 83843.
Branz
A J
AJ
D000255:Adenosine Triphosphate / Q000502:physiology; D000818:Animals; D005905:Glyburide / Q000494:pharmacology*; D006168:Guinea Pigs; D006339:Heart Rate / Q000187:drug effects; D000860:Hypoxia / Q000503:physiopathology; D007770:L-Lactate Dehydrogenase / Q000502:physiology; D017202:Myocardial Ischemia / Q000503:physiopathology*; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism*; D015221:Potassium Channels / Q000502:physiology*; D016276:Ventricular Function / Q000187:drug effects
D015221:Potassium Channels; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D005905:Glyburide