[Myocardial polyamine metabolism and the ischemia-reperfusion injury in the rat heart].

OBJECTIVE: To observe the polyamines metabolism changes in rat cardiomyocytes underwent ischemia-reperfusion (I/R) injury.

METHODS: A branch of the descending left coronary artery was occluded to induce rat myocardial I/R injury (30 min ischemia followed by 2 h, 6 h, 12 h, and 24 h reperfusion). RT-PCR and Western blot were performed to detect the expression of spermidine/spermine N1-acetyltransferase (SSAT) and ornithine decarboxylase (ODC), the concentrations of polyamines were measured with high performance liquid chromatography in hearts with or without I/R.

RESULTS: The myocardial transcription and expression of SSAT and ODC were significantly upregulated. Compared with the sham group, ODC mRNA and SSAT mRNA respectively increased 3.1 fold and 3.8 fold and their proteins respectively increased 3.1 fold and 2.9 fold at 24 h of reperfusion (P < 0.01); the concentrations of spermidine, spermine and the total polyamine pool respectively decreased by 33.6%, 35.3% and 32.9% while putrescine concentration increased by 58.9% at 24 h of reperfusion (P < 0.01).

CONCLUSION: Our results suggest that ischemia-reperfusion in the heart may affect polyamine metabolism and the disturbance of polyamine metabolism might thus play a critical role in myocardial I/R injury in this model.