Age-associated differences in response to sevoflurane postconditioning in rats.

BACKGROUND

Experimental evidence suggests that anesthetic preconditioning and postconditioning could effectively attenuate myocardial ischemia/reperfusion (I/R) injury. In this study, we aimed at investigating whether there are age-associated differences in response to sevoflurane postconditioning during myocardial I/R injury in young and old rats, and explore the underlying molecular mechanisms.

METHODS

Young and old rats were subjected to 30 min myocardial ischemia, followed by 2 h of reperfusion, with or without sevoflurane postconditioning.

RESULTS

Both 1 and 2 minimal aveolar concentration (MAC) sevoflurane postconditioning reduced infarct size (IS) (34 ± 3% and 32 ± 2% vs. 58 ± 5%, p < 0.05) and apoptotic index (8 ± 1% and 7 ± 1% vs. 15 ± 2%, p < 0.05) in young rats, compared to young control group. In contrast, they could not reduce IS (45 ± 3% and 43 ± 3% vs. 47 ± 3%, p > 0.05) and apoptotic index (28 ± 3% and 25 ± 2%, vs. 26 ± 2%, p > 0.05) in old rats, compared to old control group. Mechanistically, we found that the phosphorylation of both Akt and ERK1/2 but not STAT3 was substantially enhanced after sevoflurane postconditioning in young rats, compared to young control group, but not in old rats, relative to old control group.

CONCLUSION

There are age-related differences after exposure to sevoflurane postconditioning that protects young, but not old rat hearts against I/R injury, which may be at least associated with the inability to activate Akt and ERK1/2.