Effect of nicotine pretreatment on cardiac function following myocardial ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of nicotine pretreatment on cardiac function following myocardial ischemia-reperfusion (I/R) in rats.Methods Sixty male Sprague-Dawley rats,weighing 200-250 g,were randomly divided into 3 groups (n =20 each):sham operation group (group S),group I/R and nicotine pretreatment group (group N).The rats were anesthetized with intraperitoneal 20％ urethane 1 g/kg,tracheostomized and mechanically ventilated.Myocardial ischemia was induced by occlusion of the left anterior descending branch of coronary artery for 30 min followed by 120 min of reperfusion.The left anterior descending branch of coronary artery was only exposed,but not occluded in group S.Nicotine 400 μg/kg was injected intravenously via the right jugular vein at 30 min before myocardial ischemia in group N.The equal volume of normal saline was injected instead in groups S and I/R.Before ischemia,at 30 min of ischemia and at 30 and 120 min of reperfusion,10 rats from each group were chosen for record of left ventricular systolic pressure (LVSP),left ventricular diastolic pressure (LVDP),± dp/dtmax,HR and mean arterial pressure (MAP).Blood samples were collected from the right carotid artery of the left 10 rats in each group at 60 min of reperfusion to measure plasma CK-MB activity and cTnI and TNF-α concentrations.Results Compared with group S,MAP and LVSP at T2,3 and HR,LVDP and ± dp/dtmax at T1-3 were significantly decreased,and the plasma CK-MB activity and cTnI and TNF-α concentrations were increased in group I/R,and LVDP at T1,2 and HR and ± dp/dtmax at T1-3 were significantly decreased,and the plasma CK-MB activity and cTnI and TNF-α concentrations were increased in group N (P ＜ 0.05).Compared with group I/R,MAP,HR,LVSP,LVDP and ± dp/dtmax were significantly increased at T3,and the plasma CK-MB activity and cTnI and TNF-α concentrations were decreased in group N (P ＜ 0.05).Conclusion Nicotine pretreatment can reduce myocardial I/R injury through activating cholinergic anti-inflammatory pathway,thus improving cardiac function in rats.