Role of acetaldehyde dehydrogenase 2 in hippocampus in memory decline after myocardial ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the role of acetaldehyde dehydrogenase 2 (ALDH2) in hippocampus in memory decline after myocardial ischemia-reperfusion (I/R) in rats.Methods:Twenty-four healthy male Sprague-Dawley rats, aged 2-3 months, weighing 220-280 g, were divided into 3 groups ( n=8 each) using a random number table method: sham operation group (group S), myocardial I/R group (group I/R) and ALDH2 agonist ALDA-1 group (group ALDA-1). Myocardial I/R was induced by 30 min occlusion of left anterior descending branch of coronary artery followed by 120 min reperfusion in anesthetized animals.ALDA-1 10 mg/kg was intraperitoneally injected at 5 min before ischemia in group ALDA-1.The positioning navigation training in Morris water maze test was started from 6 days before developing the model.The spatial exploration in Morris water maze test was performed at 24 h after developing the model.The rats were sacrificed after the end of behavioral experiment, and the hippocampus was extracted for microscopic examination of the pathological changes (by hematoxylin and eosin staining) and for determination of the apoptosis index (AI) (by TUNEL staining), activity of ALDH2 (by colorimetry), contents of 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) (by enzyme-linked immunosorbent assay), and expression of ALDH2 and 4-HNE (by Western blot). Results:Compared with group S, the number of crossing the original platform was significantly decreased, the time spent in the target quadrant was shortened, the activity of ALDH2 in the hippocampus was decreased, the expression of 4-HNE was up-regulated, and the contents of 4-HNE and MDA and AI were increased in group I/R ( P<0.05). Compared with group I/R, the number of crossing the original platform was significantly increased, the time spent in the target quadrant was prolonged, the ALDH2 activity was increased, the expression of 4-HNE was down-regulated, and the contents of 4-HNE and MDA and AI were decreased in group ALDA-1 ( P<0.05). There was no significant difference in ALDH2 expression in hippocampus among the three groups ( P>0.05). Conclusions:The mechanism of memory decline developed after myocardial I/R may be related to the decrease in ALDH2 activity and promotion of accumulation of aldehydes in the hippocampus of rats.