Effects of antidigoxin antiserum on endoxin levels, apoptosis and the expression of Bax and Bcl-2 protein in ischaemia-reperfusion myocardium.
The aim of the present study was to investigate the effects of antidigoxin antiserum (ADA), an endoxin special antagonist, on endoxin levels, apoptosis and the expression of the apoptosis-related protein bcl-2 and bax in myocardial ischaemia-reperfusion (MIR). The left anterior descending coronary artery was subjected to 30 min ischaemia followed by 45 min reperfusion in open-chest anaesthetized rats. The rats were divided randomly into seven groups: a sham-operated group, an MIR group, a vehicle control (normal saline) group, and groups receiving verapamil (5 mg/kg) or ADA (9, 18 and 36 mg/kg). The drugs were injected into rats via the femoral vein before reperfusion was commenced. Myocardial endoxin levels were measured by radioimmunoassay. Apoptotic cells was detected using the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling method. The expression of the apoptosis-related proteins bcl-2 and bax was detected by immunohistochemistry and their semiquantification scores were recorded by a computer image analysis system. Myocardial endoxin levels, the number of apoptotic cells and bax protein expression were increased in the MIR group compared with the sham group. Although bcl-2 protein expression was elevated in the MIR group, there was no significant difference between the MIR and sham groups. However, the ratio of bcl-2/bax was significantly decreased in the MIR group. In the group receiving 36 mg/kg ADA, myocardial endoxin levels, the number of apoptotic cells and bax protein expression were significantly decreased; bcl-2 protein expression was enhanced. The bcl-2/bax ratio was increased. The results suggest that ADA inhibited myocardial apoptosis induced by MIR in rats. The mechanisms involved require further investigation, but the present study may suggest that ADA prevents bax upregulation and enhances bcl-2 upregulation by antagonizing the effects of endoxin.
Ke
Yong-Sheng
YS
Department of Cardiology, Yijishan Hospital, Wannan Medical College, Wuhu, Peoples Republic of China. keyongsheng@medmail.com.cn
Liu
Zhao-Fang
ZF
Wang
De-Guo
DG
Wang
He-Gui
HG
D000818:Animals; D019138:Antibodies, Blocking / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D002298:Cardenolides; D002316:Cardiotonic Agents / Q000037:antagonists & inhibitors* / Q000276:immunology*; D004077:Digoxin / Q000037:antagonists & inhibitors* / Q000276:immunology* / Q000378:metabolism*; D007150:Immunohistochemistry; D007202:Indicators and Reagents; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects / Q000201:enzymology; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000473:pathology*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000096:biosynthesis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012503:Saponins / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D051028:bcl-2-Associated X Protein
D019138:Antibodies, Blocking; C494828:Bax protein, rat; D002298:Cardenolides; D002316:Cardiotonic Agents; D007202:Indicators and Reagents; D019253:Proto-Oncogene Proteins c-bcl-2; D012503:Saponins; D051028:bcl-2-Associated X Protein; C034504:digoxin-like factors; D004077:Digoxin; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium