The Changes Of 5-HT In Rat's Myocardium, Dorsal Root Ganglion And Medulla Spinalis Following The Coronary Artery Occlusion And The Intervention Effects Of Morphine, Phentolamine, Esmolol And Atropine

Objective To investigate the role of Neurogenic mechanism and the mechanism of cardio-protection of medico-intervene during acute myocardial ischemia the observation was made on the changes in serotonin(5-HT) in the ischemic and the non-ischemic myocardium,dorsal root ganglion,comu dorsale medulla spinalis and comu rentrale medulla spinalis induced by coronary artery occlusion (CAO) in rats.Methods (1)Adult male Sprague-Dawley rats, weighing 270-300g were randomized assigned to two groups:CAO group and Control group.Each group was divided into four sub-group(n=6) which were observed at 0.5h,1h,3h and 6h. The left anterior descending coronary artery was occluded(CAO) except for Control group. The ischemic and the non-ischemic myocardium,dorsal root ganglion,comu dorsale medulla spinalis and comu rentrale medulla spinalis were excised as scheduled and processed for 5-HT immunohistochemistry(IHC) and in situ hybridization(ISH) examination. (2)Adult male Sprague-Dawley rats, weighing 270-300g were randomly divided into six groups: Control group,Ischemia group,Morphine group, Phentolamine group, Esmolol group and Atropine group. The left anterior descending coronary artery was occluded (CAO) except for Control group for 3 hours. The rats were pre-administrated 1.25mg.kg^-1 Morphine in Morphine group,0.5mg.kg^-1 Phentolamine in Phentolamine group, 3mg.kg^-1 Esmolol in Esmolol group and 1mg.kg^-1 Atropine in Atropine group through caudal vein 15min before CAO. The ischemic and the non-ischemic myocardium,dorsal root ganglion,comu dorsale medulla spinalis and comu rentrale medulla spinalis were excised as scheduled and processed for 5-HT immunohistochemistry(IHC) and Enzyme Immunometric Assay(EIA) examination.Results (1) 5-HT levels in myocardium of ischemic areas and myocardium of non-ischemic areas, dorsal root ganglion,comu dorsale medulla spinalis and comu rentrale medulla spinalis were significantly elevated after CAO when compared with control group and peaked in rats of CAO3h group; In the myocardium of non-ischemic areas and comu rentrale medulla spinalis, 5-HT levels were less than those in myocardium of ischemic areas and comu dorsale medulla spinalis in CAO groups. (2) 5-HT synzyme mRNA was detected in rat's myocardium, dorsal root...