Limb ischemia preconditions myocardium:the role of nitric oxide and neurogenic pathway / 中国药理学通报

ABSTRACT

Aim To investigate a possible role for nitric oxide and neurogenic pathway in the protective effect of the limb preconditioning on the ischemic-reperfusion myocardium.Methods 64 Wistar rats were randomly divided into one of the four experimental groups.In Group Ⅰ,the rats underwent 30 min occlusion of the left anterior descending coronary artery,and 120 min reperfusion.In Group PL,the rats underwent four cycles of 5 min occlusion and reperfusion of both hind limbs using a tourniquet before the experiment was continued as in Group Ⅰ.In Group PL-N and Group PL-H,rats were administered with L-Nitro-Arginine Methyl Ester(L-NAME)10 mg?kg-1 or hexamethonium chloride 20 mg?kg-1,intravenously,20 min before IPC.Infarct size,as a percentage of the area at risk,was determined by triphenyltetrazolium chloride staining.And other 8 rats in each group,at the end of the experiment,all rats were killed and myocardium were stored in liquid nitrogen for the measurement of NO,NOS,iNOS and iNOS mRNA.Results The myocardial infarct size(IS)was decreased significantly in Group PL and Group PL-H compared with Group Ⅰ(P