Effect of Ca-antagonists, beta-blockers and antioxidant during reperfusion period

The purpose of this study was to assess the influence of the radical scavenger (MTDQ-DA), Ca-antagonist (Verapamil) and ultrashort-acting beta-blocker (Brevibloc) on arachidonic acid metabolism and free radical mediated damage. In dog experiments, the left descending coronary artery (LAD) was ligated for 45 min or 90 min followed by one hour reperfusion. Blood samples were taken at different times of occlusion and recirculation for determination of 6-keto PGF1 alpha and TXB2. At the end of the experiments heart tissue samples were excised from injured areas and from the intact part of the left ventricular muscle. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD) as well as prostacyclin and thromboxane were determined in tissue samples. Free radical mediated damage (increased lipid peroxidation and exhaustion of endogenous scavengers) could be diminished significantly by antioxidant treatment and moreover, therapy of Verapamil and Brevibloc preserved reduced. It was characteristic that release of endoperoxides was present in each case but the highest values were measured in non-treated animals. Tissue content of prostacyclin and thromboxane varied in differently treated groups, however the altered ratio of PGF1 alpha and TXB2 showed strong influence of the antioxidatnt, Ca-antagonist and beta-blocker.