Emulsified isoflurane produces cardiac protection after ischemia-reperfusion injury in rabbits.
BACKGROUND
In this study, we examined the cardioprotective effects of parental emulsified isoflurane compared with inhaled isoflurane.


METHODS
Thirty-two rabbits were subjected to 30 min of myocardial ischemia induced by temporary ligation of the left anterior descending coronary artery followed by 3 h of reperfusion. Before left anterior descending coronary artery occlusion, the rabbits were randomly allocated into one of four groups (eight for each group): group C, no ischemia preconditioning treatment; group IS, inhaled isoflurane 1.1% end-tidal; group EI, a continuous infusion of 8% emulsified isoflurane to an end-tidal concentration of 0.64%; and group IN, a continuous infusion of 30% Intralipid started 30 min. Treatments were started 30 min before ischemia followed by a 15 min washout period for isoflurane groups. Myocardial infarct volume, lactate dehydrogenase, and creatine kinase levels were measured and changes in mitochondrial ultrastructure assessed after 3 h myocardial reperfusion.


RESULTS
Myocardial infarct size 3 h after reperfusion was lower in groups IS and EI compared with groups C and IN (20% +/- 8%, 18% +/- 8%, 39% +/- 6%, and 34% +/- 9%, respectively, P < 0.01). There were no differences in myocardial infarct size between groups IS and EI or between groups C and IN. Plasma lactate dehydrogenase and creatine kinase levels were lower in group IS (456 +/- 58 U/L and 1725 +/- 230 U/L) and group EI (451 +/- 54 U/L and 1686 +/- 444 U/L) 3 h after myocardial reperfusion compared with groups C (676 +/- 82 U/L and 2373 +/- 529 U/L; P < 0.01). Mitochondrial ultrastructure changes were less pronounced in groups IS and EI compared with group C.


CONCLUSIONS
Our results indicate that, in rabbits, i.v. emulsified isoflurane provides similar myocardial protection against ischemia-reperfusion injury as inhaled isoflurane.
Rao
Yan
Y
Department of Anesthesiology, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei, China.
Wang
Yan-lin
YL
Zhang
Wen-sheng
WS
Liu
Jin
J
D000280:Administration, Inhalation; D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000818:Animals; D003331:Coronary Vessels / Q000601:surgery; D003402:Creatine Kinase / Q000097:blood; D019610:Cytoprotection; D004195:Disease Models, Animal; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage*; D007262:Infusions, Intravenous; D007530:Isoflurane / Q000008:administration & dosage*; D007770:L-Lactate Dehydrogenase / Q000097:blood; D008026:Ligation; D008297:Male; D046529:Microscopy, Electron, Transmission; D008929:Mitochondria, Heart / Q000187:drug effects / Q000648:ultrastructure; D009203:Myocardial Infarction / Q000201:enzymology / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D017202:Myocardial Ischemia / Q000150:complications / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D015428:Myocardial Reperfusion Injury / Q000201:enzymology / Q000209:etiology / Q000473:pathology / Q000517:prevention & control*; D009206:Myocardium / Q000201:enzymology / Q000473:pathology*; D020011:Protective Agents / Q000008:administration & dosage*; D011817:Rabbits; D013997:Time Factors
D018685:Anesthetics, Inhalation; D005217:Fat Emulsions, Intravenous; D020011:Protective Agents; D007530:Isoflurane; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase