Aims: 

The study was aimed to explore the effect of diabetes mellitus (DM) on the expression of PPAR isoforms (key transcriptional regulators of lipid metabolism and energy production) and their role in myocardial ischaemia/ reperfusion injury (I/R).

Methods: 

In the Langendorff-perfused hearts of rats with 5-day DM (STZ) and the controls (C) subjected to 30-min LAD occlusion and 2-h reperfusion, were measured mRNA expression (RT-PCR) of alpha, beta and gamma isoforms of PPAR before and after I/R and infarction size (IS; TTZ).

Results: 

Baseline levels of PPAR isoforms were significantly increased in the DM group as compared with C. Marked down-regulation of all three isoforms following I/R in C was attenuated in diabetics, and PPAR alpha was even significantly increased. IS normalized to the area at risk (AR) size was significantly lower in DM group as compared with C (IS/AR 15.1 ± 3.0%vs. 37.3 ± 3.1%; P < 0.05).

Conclusions: 

Increased expression of PPAR might reflect changes in lipid metabolism induced by DM. On the other hand, maintained levels of PPAR isoforms after I/R might indicate their role in higher cardiac resistance to I/R in the acute phase of DM. Grants UK19/2007, 2/5110/25, MVTS SR-GR 15, APVT-51-027404, GSRT- 759 5190/2005.

Groups	PPAR alpha/GAPDH	PPAR beta/GAPDH	PPAR gamma/GAPDH
C	0.156 ± 0.015	0.056 ± 0.003	0.180 ± 0.010
I/R	0.097 ± 0.010†	0.028 ± 0.010†	0.122 ± 0.016†
DM	0.186 ± 0.019*	0.094 ± 0.015*	0.205 ± 0.014*
DM+I/R	0.232 ± 0.046*†	0.072 ± 0.014*	0.210 ± 0.031
*-p < 0.05 vs. non-diabetics, †-p < 0.05 vs. baseline