Dihydroxyflavonol reduces post-infarction left ventricular remodeling by preventing myocyte apoptosis in the non-infarcted zone in goats.
BACKGROUND
Myocyte apoptosis is considered to be the major causative factor of left ventricular (LV) remodeling following myocardial infarction (MI). We previously reported that 3', 4'-dihydroxyflavonol (DiOHF), was able to suppress oxidative stress and preserve the expression of endothelial nitric oxide synthase during myocardial reperfusion injury, which may benefit the reduction of myocyte apoptosis. We therefore aimed to evaluate the potential actions of DiOHF against myocyte apoptosis and post-infarction LV remodeling in this study.


METHODS
Following experimental MI, surgical instrumented goats were randomly assigned into vehicle and DiOHF (2 mg/kg; i.v., daily) groups to receive 4 weeks of reperfusion with corresponding treatments. LV pressure recordings and echocardiogram were performed at baseline, 2 and 4 weeks of reperfusion. Myocardial tissues were collected in the end to determine infarct size and apoptosis related assays.


RESULTS
LV end-diastolic volume and diameter were significantly increased 4 weeks after MI in the vehicle group, accompanied by reduced posterior wall thickness, septal thickness and LV mass, whereas those changes were markedly prevented by DiOHF treatment. Similarly, significantly reduced infarct size was found in DiOHF group as compared to vehicle group, and DiOHF dramatically inhibited the increase in LV end-diastolic pressure and the reductions in ejection fraction, fraction shortening and dP/dt(max). Moreover, DiOHF treatment significantly reduced the extent of myocyte apoptosis detected by TUNEL assay, enhanced the protein expression of caspase-3, Fas, Bax and cytochrome c in the non-infarcted myocardium in comparison to vehicle.


CONCLUSIONS
Daily DiOHF treatment during the reperfusion period after MI in the ovine hearts markedly reduced the magnitude of post-infarction LV remodeling through the inhibition of myocyte apoptosis in the remote non-infarcted myocardium.
Wang
Sheng
S
Department of Cardiothoracic Surgery, Shanghai 10th People's Hospital, Tongji University, Shanghai, China. sheng_wang@tom.com
Fei
Ke
K
Xu
Ya-wei
YW
Wang
Liang-xu
LX
Chen
Yan-qin
YQ
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D004452:Echocardiography; D005260:Female; D044948:Flavonols / Q000494:pharmacology*; D006041:Goats; D020287:In Situ Nick-End Labeling; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000503:physiopathology*; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects*; D011897:Random Allocation; D020257:Ventricular Remodeling / Q000187:drug effects*; D051028:bcl-2-Associated X Protein / Q000378:metabolism; D019014:fas Receptor / Q000378:metabolism
D044948:Flavonols; D051028:bcl-2-Associated X Protein; D019014:fas Receptor; D045304:Cytochromes c; D053148:Caspase 3