[Effect of cortisol on ischemic preconditioning in rabbit hearts].
OBJECTIVE
To determine the effects of reacting cortisol on ischemic preconditioning (IPC).


METHODS
Thirty rabbits were randomized into ischemic preconditioning (IPC) group, etomidate (Etom) group, ischemic/reperfusion (IR) group, methylprednisolone (MP) group and a control group. The ratios of infarction size versus risk area (Infarct/Risk) were calculated. The elevations of serum CK activity and cTnI concentrations as well as serum cortisol concentrations were measured.


RESULTS
The ratios of Infarct/Risk were 5.9%+/-2.8% for IPC, 11.3%+/-3.6% for Etom, 26.8%+/-4.5% for IR and 18.2%+/-3.7% for MP. The elevations of serum CK activity (U/L) were 255+/-89 for IPC, 314+/-160 for Etom, 855+/-371 for IR and 768+/-404 for MP, the elevations of serum cTnI concentrations (microg/L) were 3.6+/-0.6 for IPC, 5.9+/-2.0 for Etom, 8.1+/-3.6 for IR and 6.1+/-2.3 for MP. Those indicators among groups are all significantly different (P<0.01). Cortisol reacting was markedly diminished in Etom group.


CONCLUSIONS
A blunted cortisol reaction can markedly undermine the benefit of ischemic preconditioning, methylprednisolone show a certain myocardial protection. Cortisol may play an important role in the IPC process.
Xu
Hua-shan
HS
Department of Cardiothoracic Surgery, Xiangya Hospital, Central South University, Changsha 410008, China. xhhh9@hotmail.com
Chen
Sheng-xi
SX
Luo
Wan-jun
WJ
Gao
Qun-ao
QA
Yang
Yang
Y
D000818:Animals; D052279:Creatine Kinase, MB Form / Q000097:blood*; D005045:Etomidate / Q000627:therapeutic use; D005260:Female; D019157:Ischemic Preconditioning, Myocardial; D008297:Male; D008775:Methylprednisolone / Q000627:therapeutic use*; D015428:Myocardial Reperfusion Injury / Q000097:blood / Q000517:prevention & control*; D011817:Rabbits; D011897:Random Allocation
D052279:Creatine Kinase, MB Form; D008775:Methylprednisolone; D005045:Etomidate