Aprotinin abolishes sevoflurane postconditioning by inhibiting nitric oxide production and phosphorylation of protein kinase C-delta and glycogen synthase kinase 3beta.
BACKGROUND
It remains controversial whether aprotinin use during cardiac surgery is cardioprotective or detrimental. In contrast, volatile anesthetics may offer cardioprotection perioperatively. Increased nitric oxide, protein kinase C activation, and glycogen synthase kinase 3beta inhibition play a role in sevoflurane-induced cardioprotection. The authors investigated whether aprotinin affects sevoflurane postconditioning.


METHODS
Isolated guinea pig hearts underwent 30 min of global ischemia and 120 min of reperfusion (control [CTL]). Postconditioning was elicited with sevoflurane (2%) for 2 min at reperfusion onset (POST). Aprotinin (250 kallikrein inhibitor units/ml) was administered for 5 min at reperfusion onset (POST + APRO and CTL + APRO). In additional experiments, both sevoflurane and aprotinin were given before ischemia and throughout the reperfusion period (SEVO + APRO (throughout)) to mimic clinical conditions. Left ventricular developed and end-diastolic pressures and infarct size were measured. Western blot analysis determined phosphorylated protein kinase C-delta, protein kinase C-delta, Akt, and glycogen synthase kinase 3beta expression. Nitric oxide production during reperfusion was measured by nitric oxide sensor.


RESULTS
After ischemia-reperfusion, POST had significantly higher left ventricular developed (56 +/- 11 vs. 26 +/- 8 mmHg [mean +/- SD]) and lower end-diastolic pressures (20 +/- 9 vs. 47 +/- 15 mmHg) and reduced infarct size (15 +/- 3% vs. 41 +/- 10%) versus CTL. Aprotinin abolished these improvements. Expressions of phospho-Akt (activated), phospho-protein kinase C-delta (activated), and phospho-glycogen synthase kinase 3beta (inhibited) were significantly increased in POST. Aprotinin attenuated these increased expressions. Nitric oxide production after reperfusion was higher in POST than in CTL, but not in POST + APRO.


CONCLUSIONS
Aprotinin abolishes sevoflurane postconditioning, associated with inhibited phosphorylation of Akt, protein kinase C-delta, and glycogen synthase kinase 3beta and reduced nitric oxide production.
Inamura
Yoshitaka
Y
Department of Anesthesiology, Osaka Dental University, Japan.
Miyamae
Masami
M
Sugioka
Shingo
S
Kaneda
Kazuhiro
K
Okusa
Chika
C
Onishi
Anna
A
Domae
Naochika
N
Kotani
Junichiro
J
Figueredo
Vincent M
VM
D000818:Animals; D007611:Aprotinin / Q000494:pharmacology*; D015153:Blotting, Western; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006168:Guinea Pigs; D008297:Male; D008738:Methyl Ethers / Q000494:pharmacology*; D009203:Myocardial Infarction / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D009569:Nitric Oxide / Q000096:biosynthesis*; D010766:Phosphorylation; D051745:Protein Kinase C-delta / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*; D000077149:Sevoflurane; D016277:Ventricular Function, Left
D008738:Methyl Ethers; D015842:Serine Proteinase Inhibitors; D009569:Nitric Oxide; D000077149:Sevoflurane; D007611:Aprotinin; D000071679:Glycogen Synthase Kinase 3 beta; D051057:Proto-Oncogene Proteins c-akt; D051745:Protein Kinase C-delta; D038362:Glycogen Synthase Kinase 3