去甲肾上腺素和腺苷联合应用预调心肌

目的：研究联合应用去甲肾上腺和腺苷模拟缺血预调的心肌保护效果。方法：25只新西兰大白兔随机分为对照组，缺血预处理组，腺苷预处理组，去甲肾上腺素预处理组，联合应用去甲肾上腺素和腺苷预处理组，先分别缺血或药物预处理5min,间隙10min后心肌局部缺血30min，再灌注3h，连续监测心率和血压并在预处理前和再灌注后3h经右心房采血检测肌酸磷酸激酶（CK）和丙二醛（MDA）。结果：CK和MDA值各组基础值无显著差异，再灌注后3h各预处理组显著低于对照组（P＜0．05），预处理组间无差异，但腺苷预处理时血压剧烈下降，去甲肾上腺素预处理时血压剧烈升高，联合应用去甲肾上腺素和腺苷预处理时血压平衡，结论：联合应用去甲肾上腺素和腺苷可使心肌对缺血产生有效预适应，同时避免单独应用去甲肾上腺素或腺苷模拟缺血预调时血压的剧烈变化。

Ischemic Preconditioning with Co-infusion of Adenosine and Norepinephrine

Objective To evaluate the cardiac protective effect of co-infusion of adenosine and norepinephrine. Methods Twenty-five New Zealand white rabbits were randomly divided into 5 groups. Ischemia preconditioning or drug infusion mimicking ischemia preconditioning was first carried out for 5min, then reperfusion for 10min, regional ischemia again for 30min, and subsequently reperfusion for 3h. HR and BP were monitored during the experiments. Serum CK and MDA were determined before ischemic or drug preconditioning (baseline) and 3h after reperfusion. Results Basal serum CK and MDA were comparable in all groups. Serum CK and MDA in all preconditioning groups were significantly lower than that in the control group after 3h of reperfusion (P<0.05). Difference was not significant among the preconditioning groups. Blood pressure was found lowered significantly during adenosine infusion; intravenous norepinephrine infusion significantly caused elevation of mean arterial blood pressure; but co-infusion of adenosine and norepinephrine caused no significant change. Conclusion Co-infusion of adenosine and norepinephrine seems able to precondition the heart without any significant hemodynamic change.