[Protection of hypothermic preserved isolated rat hearts by resveratrol and its underlying mechanism].

OBJECTIVE: To investigate whether resveratrol (RES) plays a protective role in hypothermic preserved isolated rat hearts and whether it is mediated by regulation of silent information regulator protein-1 (Sirt-1) expression.

METHODS: The Langendorff model of isolated rat heart was used. After stored in different Celsior solution at 4 degrees C for 9 h, SD rat hearts were randomly divided into 7 groups: blank control group;9 h group (soley hypothermic preservation for 9 h); RES group (3, 10, 30 micromol/L RES treatment plus hypothermic preservation for 9 h ), niacinamide (NAM) group (40 micromol/L NAM added in Celsior solution plus hypothermic preservation for 9 h), RES + NAM group (30 micromol/L RES and 40 micromol/L NAM were added in Celsior solution plus hypothermic preservation for 9 h). The morphological changes of cardiomyocytes were detected by the HE staining with the light microscope. The mRNA and protein expression levels of Sirt-1 were detected by Real-Time PCR and Western blot respectively.

RESULTS: (1) Compared with the blank control group, myocardiocytes were injured remarkably in the 9 h group and the Sirt-1 mRNA and protein expression levels were decreased significantly (P < 0.01); (2) Compared with the 9 h group, rat myocardial injury was alleviated gradually in 3, 10, 30 micromol/L RES group and the Sirt-1 mRNA and protein expression levels were increased in a dose-dependent manner (P < 0.05); (3) The above protective effects of RES were attenuated by Sirt-1 inhibitor NAM.

CONCLUSION: RES can protect myocardiocytes from injury caused by long range hypothermic preservation and this protective effect maybe mediated by upregulation of Sirt-1 expression.