目的比较不同剂量盐酸戊乙奎醚(PHC)预处理对大鼠心肌缺血/再灌注(I/R)损伤的保护作用。方法健康雄性Wistar大鼠48只,按随机数字表法分为空白对照组(Sham)、空白+1.0mg/kgPHC对照组(Sham+H—PHC组)、I/R组、I/R+0.1mg/kgPHC预处理组(I/R+L—PHC组)、I/R+0.3mg/kgPHC预处理组(I/R+M—PHC组)及I/R+1.0mg/kgPHC预处理组(I/R+H—PHC组)6组,每组8只。采用冠状动脉结扎制备心肌I/R损伤模型,于制模前30min给予相应剂量PHC进行预处理。再灌注3h后记录左室舒张期末压(LVEDP)、左室收缩期末压(LVESP)、射血分数(EF)和短轴缩短率(FS);测定血清天冬氨酸转氨酶(AST)、肌酸激酶同工酶(CK—MB)、乳酸脱氢酶(LDH)含量。处死大鼠取心脏,测定心肌缺血面积(AAR)及梗死面积(AI),计算AI/AAR比值;电镜下观察心肌纤维超微结构改变。结果与Sham组和Sham+H—PHC组比较,I/R后各组大鼠均表现为LVEDP增高,LVESP、EF及Fs降低,AST、CK—MB、LDH含量升高,AI/AAR增加。与I/R组比较,不同剂量PHC预处理组LVEDP下降,LVESP、EF、FS升高,AST、CK—MB、LDH含量及AI/AAR比值下降,以中、大剂量PHC组改善最明显[LVEDP(mmHg,1mmHg=0.133kPa):11.33±1.17、9.85±1.09比15.82±1.79,LVESP(mmHg):98.9±10.6、112.8±10.0比87.8±9.2,EF:0.681±0.074、0.741±0.070比0.569±0.072,FS:(42.4±4.6)%、(46.0±5.1)%比(36.8±3.9)%,AST(U/L):386.97±80.65、298.31±54.88比603.47±173.66,CK—MB(U/L):3.12±0.84、2.88±0.72比7.14±1.54,LDH(U/L):1784.23±488.49、1629.37±436.34比2489.14±460.80,AI/AAR比值:0.284±0.014、0.223±0.008比0.377±0.011,均P〈0.05];中、大剂量PHC组比较,仅LVEDP、LYESP和AI/AAR比值差异
Objective To compare the protective effect of different dose of penehyclidine hydrochloride (PHC) in rats with myocardial ischemia/reperfusion (I/R) injury. Methods Forty-eight healthy male Wistar rats were randomly divided into six groups (n = 8 each): sham group, sham + 1.0 mg/kg PHC group (sham + H-PHC group), I/R group, I/R + 0.1 mg/kg PHC preconditioning group (I/R + L-PHC group), I/R + 0.3 mg/kg PHC preconditioning group (I/R + M-PHC group), and I/R + 1.0 mg/kg PHC preconditioning group (I/R + H-PHC group). I/R injury model was reproduced by ligation followed by release of the coronary artery, and PHC in different dosages was given at 30 minutes before model reproduction. At 3 hours after reperfusion, the left ventricular end-diastolic pressure (LVEDP), left ventricular end-systolic pressure (LVESP), ejection fraction (EF), and fractional shortening (FS) were recorded. The levels of aspertate aminotransferase (AST), MB isoenzyme of creatine kinase (CK-MB), and lactate dehydrogenase (LDH) were determined. The myocardial tissues were harvested for the determination of the area at risk (AAR) and the infarct area (AI), and the percentage of AI/AAR was calculated. The examination of myocardial fiber was performed with electron microscopy. Results Compared with sham and sham + H-PHC groups, LVEDPwas increased in I/R groups, LVESP, EF and FS were decreased, and the levels of AST, CK-MB and LDH, as well as the AI/AAR were increased. Compared with I/R group, in pretreatment groups with different doses of PHC, LVEDP was decreased, LVESP, EF and FS were increased, the levels Of AST, CK-MB, LDH, and AI/AAR were also decreased, especially in I/R+M-PHC and I/R+H-PHC groups [LVEDP (mmHg, 1 mmHg = 0.133 kPa): 11.33± 1.17, 9.85 ±1.09 vs. 15.82± 1.79, LVESP ( mmHg ): 98.9 ±10.6, 112.8 ±10.0 vs. 87.8±9.2, EF: 0.681 ± 0.074, 0.741 ± 0.070 vs. 0.569±0.072, FS: (42.4±4.6)%, (46.0±5.1)% vs. (36.8±3.9)%,