Effects of glibenclamide on hydroxyl radical formation in the postischaemic reperfused heart with or without inhalation anaesthetics.
OBJECTIVE
We investigated whether glibenclamide (glyburide) affects myocardial metabolism and hydroxyl radical formation in the rat heart-lung preparation with or without inhalation anaesthetics.


METHODS
Thirty-seven male Wistar rats were allocated to four groups: (a) control group (C), received vehicle only; (b) group G, received glibenclamide 10 microM L-1; (c) group I, received glibenclamide 10 microM L-1 and 1.4% isoflurane during perfusion; (d) group S, received glibenclamide 10 microM L-1 and 2.7% sevoflurane during perfusion. Glibenclamide was administered 7 min after the start of perfusion. Ten minutes later, the heart was rendered globally ischaemic for 10 min by reducing the preload and afterload to zero, and then the heart was reperfused for 10 min. The formation of hydroxyl radicals in perfusate blood and heart was measured with high performance liquid chromatography using salicylic acid. Hydroxyl radicals react with salicylic acid, yielding dihydroxybenzoic acids.


RESULTS
The recovery time from ischaemia in group G was significantly longer than the other groups. However, there were no differences in myocardial metabolites and dihydroxybenzoic acids concentrations in the perfusate and heart among the four groups.


CONCLUSIONS
Glibenclamide prolonged recovery time from ischaemia, but did not affect hydroxyl radical formation in the postischaemic reperfused heart. In addition, isoflurane and sevoflurane shortened this time. These facts suggest that mechanisms other than effects of volatile anaesthetics on hydroxyl radical formation are responsible for their protective effects in this model.
Kashimoto
S
S
Department of Anaesthesiology, Yamanashi Medical University, Shimokato 1110, Tamaho-cho, Nakakoma-gun, Yamanashi, Japan 409-3898. satoshik@res.yamanashi-med.ac.jp
Furuya
A
A
Kume
M
M
Yamaguchi
T
T
Kumazawa
T
T
D000255:Adenosine Triphosphate / Q000378:metabolism; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D005905:Glyburide / Q000494:pharmacology*; D006003:Glycogen / Q000378:metabolism; D006439:Hemodynamics / Q000187:drug effects; D062385:Hydroxybenzoates / Q000378:metabolism; D017665:Hydroxyl Radical / Q000378:metabolism*; D007530:Isoflurane / Q000494:pharmacology*; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D026902:Potassium Channel Blockers / Q000494:pharmacology*; D019289:Pyruvic Acid / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D000077149:Sevoflurane
D018685:Anesthetics, Inhalation; D062385:Hydroxybenzoates; D008738:Methyl Ethers; D026902:Potassium Channel Blockers; D017665:Hydroxyl Radical; D019344:Lactic Acid; D000077149:Sevoflurane; D019289:Pyruvic Acid; D000255:Adenosine Triphosphate; D006003:Glycogen; D007530:Isoflurane; D005905:Glyburide