Effects of phytoestrogen genistein on myocardial ischemia/reperfusion injury and apoptosis in rabbits.
OBJECTIVE
To study the effect of genistein (GST) on rabbit heart ischemia/reperfusion (I/R) injury.


METHODS
Rabbit heart I/R injury was induced by occluding the left anterior descending coronary artery for 45 min and reperfusing for 180 min. GST (1.0 mg/kg) was intravenously injected 5 min before heart ischemia. Hemodynamic data, infarct size, and cardiomyocytic apoptosis were measured. The pathologic changes of I/R myocardium were observed.


RESULTS
During the I/R, heart rate, mean arterial blood pressure, myocardial oxygen consumption, left ventricular (LV) -dp/dtmax and +dp/dtmax were decreased progressively. The infarct size was occupied 60.23 %+/-3.97 % (% of area at risk) in vehicle +I/R group while GST reduced the infarct size to 39.62 %+/-4.30 % (P<0.01). DNA ladder pattern in myocardium was revealed by agarose gel electrophoresis in vehicle +I/R group while was not found in GST+I/R group. Apoptotic cardiomyocytes were sparse within ischemic myocardium at risk in GST+I/R group as compared with that in vehicle +I/R group (TUNEL stain). Apoptosis rate in ischemic myocardium from vehicle +I/R and GST+I/R groups detected by flow cytometry were 15.33 %+/-1.31 % and 3.88 %+/-0.33 %, respectively. Fas and Bax protein expressions in ischemic myocardium of vehicle +I/R group were higher than that in GST+I/R group (P<0.01). Bcl-2/Bax ratio in vehicle +I/R group was lower than that in nonischemic myocardium (P<0.01), while in GST+I/R group, the Bcl-2/Bax ratio was higher than that in vehicle +I/R group (P<0.01).


CONCLUSIONS
GST reduced infarct size and apoptosis of myocytes in I/R rabbit heart.
Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
En-sheng
ES
Ji
Hua
H
Yue
Yu-ming
YM
Wu
Rui-rong
RR
He
D018830:Adhesins, Escherichia coli / Q000378:metabolism; D000818:Animals; D000942:Antigens, Bacterial / Q000378:metabolism; D017209:Apoptosis / Q000187:drug effects*; D036781:Fimbriae Proteins / Q000378:metabolism; D019833:Genistein / Q000494:pharmacology*; D007529:Isoflavones / Q000494:pharmacology*; D008297:Male; D017202:Myocardial Ischemia / Q000150:complications; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000473:pathology*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D032383:Myocytes, Cardiac / Q000187:drug effects* / Q000473:pathology; D048789:Phytoestrogens; D028321:Plant Preparations / Q000494:pharmacology*; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism; D011817:Rabbits; D051028:bcl-2-Associated X Protein
D018830:Adhesins, Escherichia coli; D000942:Antigens, Bacterial; D007529:Isoflavones; D048789:Phytoestrogens; D028321:Plant Preparations; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; C035391:antigen 987P, E coli; D051028:bcl-2-Associated X Protein; D036781:Fimbriae Proteins; D019833:Genistein