Abstract:Aim To observe the effect of myocardial ischemia on the expression of heart type fatty acid binding protein (H-FABP) in myocardium of rats and to explore its possible molecular mechanism.Methods SD rats were randomly divided into sham operation group and myocardial ischemia 1, 3, and 7 days groups. A model of myocardial ischemia was constructed by ligating the left anterior descending coronary artery. The heart function was assessed by detecting the cardiac hemodynamic parameters left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP) and +dp/dtmax, -dp/dtmax using PowerLab instrument. The mRNA and protein expressions of H-FABP and peroxisome proliferator-activated receptor ɑ (PPARɑ) in myocardium were detected by quantitative PCR and Western blot respectively. The survival rate of rats was observed.Results Compared with the sham operation group, hemodynamic parameters LVSP, +dp/dtmax, -dp/dtmax were decreased and LVEDP was increased continuously at 1, 3 and 7 days after myocardial ischemia (P<0.01). Results from quantitative PCR and Western blot showed that the expression of H-FABP was up-regulated at the 1 day after ischemia, but started to fall at 3 days and returned to the baseline level at 7 days after ischemia. The expression of PPARα was continuously decreased at 1, 3 and 7 days after ischemia, however, its phosphorylation was increased at 1 day and then fell subsequently. The survival rate of myocardial ischemia group was decreased significantly compared with the sham operation group.Conclusions The expression of H-FABP in ischemic myocardium is elevated at the earlier stage, which is related to the increased phosphorylation of PPARα. Then, the expression of H-FABP is decreased, which may be related to the down-regulation of the expression and phosphorylation of PPARɑ.