Effects of Shen-fu injection pretreatment on mitochondrial permeability transition and transmembrane potential following myocardial ischemia-reperfusion injury in rats

Abstract

Objective To investigate the effects of pretreatment with Shen-fu injection on mitochondrial permeability transition and mitochondrial transmembrane potential （△ψm） following myocardial ischemiareperfusion （IR） injury in rats. Methods Thirty SD rats of both sexes weighing 250-300 g were randomly divided into 3 groups with 10 animals in each group： I sham operation group （group S） ; II IR group and III Shen-fu injection group （group SFI）. The animals were anesthetized with intrapcritoneal 20% urethane 5 ml/kg. The chest was opened and the heart exposed. Myocardial IR was induced by temporary ligation of the anterior descending branch of left coronary artery maintained for 30 min, followed by 120 min reperfusion. Myocardial ischemia was confirmed by decoloration of apex and elevation of S-T segment （ 〉 0.1 mV） or erection of T wave. In group SFI, SFI 10 ml/kg was infused at 15 rain before ischemia, while in group S and IR equal volume of normal saline was infused instead of SFI. At 120 min of reperfusion, blood samples were collected from right internal carotid artery for determination of serum concentration of cTnI. The animals were then sacrificed and the hearts were immediately removed for t of myocardial mitochonerial permeability transition pore （MPTP） activity （by spectrophotometry at 540 nm） and myocardial △ψm （by, fluorospectrophotometer using rhodamine 123 as fluorescent probe）. Results Compared with group S, serum cTnI concentration and MPTP activity were significantly increased and △ψm was decreased in group IR. SFI pretreatment significantly attenuated the IR- induced increase in serum cTnI concentration and the MPTP activity and decrease in △ψm. Conclusion SFI pretreatment can protect myocardium from IR injury by attenuating the IR induced increase in MPTP opening and decrease in △ψm. Key words: SHENFU DECOCTION ; Myocardial reperfusion injury ; Mitochondria, heart ; Cell membrane permeability; Membrane potentials