Abstract: AIM: To observe the effects of pioglitazone on the hearts of the rat's models of ischemia-reperfusion in vivo.METHODS: Sprague-dawley rats were randonnly divided into two groups. One was the group of 30 min reperfusion, which was subdivided into sham (n=5), model (veahic, n=6) and pioglitzone (3mg·kg^-1, n = 7) with 30 min ischemia followed by 30min reperfusion to detect some data related to cardiac function and the area of myocardium infarction (MI). Another was the group of 2 h reperfusion, which was fur-ther subdivided into the sham (n = 5), model (venicle,n = 6), pioglitazone 0.3 mg·kg^-1 (n = 6), 1 mg·kg^-1 (n = 7) and 3 mg·kg^-1. (n = 5). Then Immunohistochemistry and in situ hybridization were performed todetect the express of MMP-2 and PPARTY and RNA.RESULTS: Compared with the model group nec/aar after injecting pioglitazone decreased by 28% (P< 0.01). The ratio of nec/lv reduced to 32% (P <0.01). Heart rate, + dp/dt_max, as well as-dp/dt_max improved dramatiely at 1 min and 30 min after reperfusion, respectively (P 0.05). In dose-dependent manner,the expression of MMP-2 protein and MRNA were de-resseed, while the PPARY protein and MRNA were en-hanced by pioglitazone.CONCLUSION: Pioglitazonehas the protective ability against I/R injury evidenced byreducing area of MI and improving cardiac function. Thismay take place through the pathway in which PPARY inhibiting MMP-2.

Key words: ischemareperfusion, pioglitazone, ap-optosis, heart, PPARY