Myocardial microdialysis of salicylic acid to detect hydroxyl radical generation during ischemia.

We examined in vivo monitoring of hydroxyl radical (.OH) generation during myocardial ischemia for 30 min by occluding the left anterior descending (LAD) in dog heart using a microdialysis technique. The hydroxyl radical reacts with salicylate and generates 2,3- and 2,5-dihydroxybenzoic acids (DHBA) which can be measured electrochemically in picomole quantity by a high pressure liquid chromatography-electrochemical (HPLC-EC) procedure. When the premature ventricular contraction (PVC) occurred at almost 25 sec intervals, marked elevation of the levels of 2,3- and 2,5-DHBA was observed in the heart dialysate of 30-min ischemia. This study demonstrated the generation of .OH in the canine heart subjected to 30-min ischemic insult.