预适应减轻大鼠下肢缺血再灌注后的心肺损伤

目的 :观察预适应 (缺血及腺苷 )对大鼠下肢缺血再灌注后心、肺损伤的保护作用。方法 :雄性SD大鼠随机分为手术组 (Ⅰ ) ,缺血预适应组 (Ⅱ ) ,腺苷预适应组 (Ⅲ ) ,假手术组 (Ⅳ )。测定再灌注后的平均动脉压。终点取心、肺组织行测定心肌ATP酶 ,心、肺组织丙二醛 (MDA)及伊文氏兰含量。结果 :组Ⅰ ,Ⅲ再灌注后平均动脉压分别为 (8.1± 1.9)kPa ,(9.2± 2 .4 )kPa ,均显著低于组Ⅱ ,Ⅳ (P <0 .0 5 )。组Ⅰ心肌Ca2 + ATP酶活力为 (5 .0 2± 0 .2 1)U·mg- 1,低于余 3组 (P <0 .0 5 )。组Ⅰ心、肺组织MDA含量和肺伊文氏兰含量显著高于余 3组。结论 :预适应能改善大鼠下肢缺血再灌注后心、肺组织和功能损伤

Protective effects of preconditioning on cardiac and pulmonary injury induced by lower extremity ischaemia reperfusion in rats

AIM: To investigate the protective effects of preconditioning on cardiac and pulmonary injury induced by lower extremity ischaemia reperfusion in rats. METHODS: SD rats were randomly divided into four groups and underwent laparotomy. The abdominal aorta was isolated and clamped below the renal artery level for 120 min then declamped for another 120 min. Group Ⅰwas taken as control. Group Ⅱ(n=8) was pretreated with ischaemia preconditioning that the lower extremities had experienced 4 times of ischaemia and reperfusion 5 min each before the 240 min treatment began. Group Ⅲ(n=8) accepted continuous drip infusion of adenosine. Group Ⅳwas sham operated. All groups were given Evan's blue dye intravenously after anesthesia. Mean artery pressure (MAP), myocardium ATPase activities and malonyldialdehyde (MDA), pulmonary MDA and Evan's blue were determined separately. RESULTS: MAP was lower in groupⅠand Ⅲ than that in group Ⅱ and Ⅳ,neither group Ⅰand Ⅲ, norⅡand Ⅳ, had significant differencesⅠ:( 8.1±1.9) kPa;Ⅱ:(11.5±1.6) kPa; Ⅲ:(9.2±2.4) kPa;Ⅳ:(12±3) kPa].Myocardium ATPase activity was lower in group Ⅰthan that in group Ⅱ,Ⅲ,Ⅳ Na +-K +ATPase (8.1±0.4) U·mg -1 vs (8.9± 2.1) U·mg -1, (9.4±1.0) U·mg -1 and ( 9.0±0.8) U·mg -1; Ca 2+ATPase (5.0±0.2) U·mg -1 vs (5.8±1.0) U·mg -1, (5.9±0.7) U·mg -1 and (5.7±0.8) U·mg -1; Mg 2+ATPase ( 4.4±0.3) U·mg -1 vs (5.2± 0.8) U·mg -1, (5.1± 0.7) U·mg -1 and (5.3±0.6) U·mg -1 , the MDA level was higher in groupⅠthan that in group Ⅱ,Ⅲ,Ⅳ. MDA(2.5±0.4) nmol·mg -1 vs (1.8± 0.7) nmol·mg -1, (1.6± 0.5) nmol·mg -1 and (1.7± 0.7) nmol·mg -1. Pulmonary MDA and Evan's blue level were higher in group Ⅰ than that in the other three groups MDA( 2.3±0.2) nmol·mg -1 vs (1.6±0.4) nmol·mg -1, (1.8±0.5) nmol·mg -1 and (1.4±0.6) nmol·mg -1; Evan's blue (3.1±1.2) μg·mg -1 vs (1.6±0.5) μg·mg -1, ( 1.5±0.3) μg·mg -1 and (0.9±0.2) μg·mg -1. CONCLUSION: Ischaemia and adenosine preconditioning had some protective effects on cardiac and pulmonary injury induced by ischaemia reperfusion of lower extremity in rats.