Effects of an Acute Bout of Strenuous Exercise on the Level of NO/NOS in Rat's Myocardium Mitochondria and Mitochondrial

Twelve 8-week-old female SD rats are randomly divided into control group(six)and exercise group(six)and let the rats of exercise group swim with heavy in 299±29 rain aver- agely,then killed to get myocardium mitochondria to measure mitochondria RCR,total NOS, mtNOS activity of myocardium,the express level of myocardiumⅢNOSmRNA,NO amount in myocardium cells and mitochondria,the ability of mitochondria's restrain to radical oxygen species and[Ca~(2+)]i.The result shows that,although the ability of rats' mitochondrial restrain to reactive oxygen species(O_2(?),(?)H)decreases,rats' myocardium mitochondrial respiration controlling rate is complete,the concentration of mitochondria free Ca(2+)is not changed.This is related to descend of contend of myocardium cells and mitochondria NO,and related to descend of mtNOS activity.