title: Blockade of anaesthetic-induced preconditioning in the hyperglycaemic myocardium: the regulation of different mitogen-activated protein kinases.
abstract: Preconditioning by volatile anaesthetics is blocked by hyperglycaemia. The regulation of mitogen-activated protein kinases during this effect has yet not been investigated. For infarct size measurements, anaesthetized rats were subjected to 25 min coronary artery occlusion followed by 120 min reperfusion. Control animals were not further treated. One group was preconditioned by two 5-min periods of desflurane inhalation (desflurane preconditioning, Des-preconditioning, 1MAC), each followed by 10-min washout. Four groups received glucose 50% in order to achieve blood glucose concentrations between 22.2 and 33.3 mM/l. Glucose infusion started 40 min before ischaemia (early hyperglycaemia, EH) and stopped with the onset of artery occlusion with (EH+Des-preconditioning) or without (EH) preconditioning. The other two groups received glucose during ischaemia (late hyperglycaemia, LH), again with (LH+Des-preconditioning) or without (LH) preconditioning. Additional hearts were excised for Western blot of mitogen-activated protein kinases. Infarct size was reduced from 51.7+/-9.0% in controls to 28.8+/-11.8% after Des-preconditioning (P<0.01 vs Con). Hyperglycaemia alone did not affect infarct size (EH, 51.5+/-9.0%, LH, 44.3+/-16.9%), but EH as well as LH blocked Des-preconditioning (49.1+/-12.3%, P<0.01, 48.1+/-17.6%, P<0.05 vs Des-preconditioning). All three mitogen-activated protein kinases showed a similar time course pattern of phosphorylation in the Des-preconditioning, EH and EH+Des-preconditioning group. Despite the lack of cardioprotection, mitogen-activated protein kinases are activated in hyperglycaemic myocardium. Therefore, it can be assumed that the hyperglycaemic induced blockade of Des-preconditioning is situated downstream or in parallel of these mitogen-activated protein kinases or involves different signal transduction pathways.
authors.affiliation: Laboratory of Experimental Intensive Care and Anaesthesiology (L.E.I.C.A.), Academic Medical Center (AMC), University of Amsterdam, Amsterdam, The Netherlands. N.C.Hauck@amc.uva.nl
authors.forename: Nina C
authors.initials: NC
authors.lastname: Weber
authors.forename: Christine
authors.initials: C
authors.lastname: Goletz
authors.forename: Ragnar
authors.initials: R
authors.lastname: Huhn
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Grueber
authors.forename: Benedikt
authors.initials: B
authors.lastname: Preckel
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schlack
authors.forename: Dirk
authors.initials: D
authors.lastname: Ebel
mesh_terms: D000777:Anesthetics / Q000494:pharmacology*; D018685:Anesthetics, Inhalation / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D015153:Blotting, Western; D000077335:Desflurane; D004562:Electrocardiography / Q000187:drug effects; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006943:Hyperglycemia / Q000378:metabolism*; D019157:Ischemic Preconditioning, Myocardial; D007530:Isoflurane / Q000031:analogs & derivatives / Q000494:pharmacology; D008297:Male; D020928:Mitogen-Activated Protein Kinases / Q000096:biosynthesis* / Q000235:genetics*; D009203:Myocardial Infarction / Q000473:pathology; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D010766:Phosphorylation; D051381:Rats; D017208:Rats, Wistar; D013778:Tetrazolium Salts; D013844:Thiazoles; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D000777:Anesthetics; D018685:Anesthetics, Inhalation; D001786:Blood Glucose; D013778:Tetrazolium Salts; D013844:Thiazoles; D000077335:Desflurane; D007530:Isoflurane; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; C022616:thiazolyl blue