Calcium overload induced by ouabain administration generated hydroxyl free radicals in the rat heart, showing a positive linear correlation with 2,3-DHBA (r2=0.976) and 2,5-DHBA (r2=0.982).
Estimación del efecto: r2 = 0.976 (2,3-DHBA); r2 = 0.982 (2,5-DHBA)
Although calcium (Ca2+) is important in cardiac dysfunction and has also been reported as a source of oxidative toxicity, the connection between Ca2+ overload and oxygen free radicals in the myocardium is not clear. We have investigated whether Ca2+ overload generates hydroxyl free radicals in rat ventricle. HPLC with electrochemical detection was used to measure the levels of 2,3- and 2,5-dihydroxybenzoic acid (DHBA) formed when the hydroxyl free radical reacts with salicylate. Ringer's solution containing salicylic acid (0.5 nmol microL-1 min-1) was infused through a microdialysis probe in the region of the left anterior descending coronary artery of the rat ventricle. A positive linear correlation was obtained between Ca2+ and hydroxyl free radical formation trapped as 2,3-DHBA (r2 = 0.976) and 2,5-DHBA (r2 = 0.982) in the myocardial dialysate. The administration of ouabain (1 mg kg-1, i.v.), a Ca2+ elevator, into the femoral vein significantly increased the level of 2,3- and 2,5-DHBA. These results indicate that Ca2+ overload generates hydroxyl free radicals in rat heart.
Obata et al. (Fri,) conducted a other in Calcium overload in myocardium. Ouabain administration (calcium elevator) was evaluated on Hydroxyl free radical formation trapped as 2,3-DHBA and 2,5-DHBA (r2 = 0.976 (2,3-DHBA); r2 = 0.982 (2,5-DHBA)). Calcium overload induced by ouabain administration generated hydroxyl free radicals in the rat heart, showing a positive linear correlation with 2,3-DHBA (r2=0.976) and 2,5-DHBA (r2=0.982).