RESUMO
A dynamic study for the activity of myocardial cytochrome oxidase from guinea pigs fed with low selenium and low phospholipid semi-synthetic diet (basal diet) or diet supplemented with selenium, phospholipid or other agents was conducted with Pye Unicam SP-1800 UV spectrophotome-ter and Circular C100.The results showed that the activity of myocardial cytochrome oxidase from animals fed with basal diet was the lowest. The single supplement of selenium or phospholipids did not increase the enzymic activity significantly. Only when selenium and phospholipids, especially all the ingredients related to the phospholipids metabolism, such as choline and methionine were supplemented simultaneously, the enzymic activity (velocity constant K) then increased significantly, and sometime even exceeded that of the group fed with normal diet. In the sametime the ratio of phospholipids in heart and the cardiolipin content was close to that of control animals fed with normal diet. The significance of boundary lipids in heart for membranous enzyme and the pathogenesis of Keshan disease was discussed.