Effects of propofol on ischemia and reperfusion in the isolated rat heart compared with thiamylal

The aim of the present study was to investigate whether clinical doses of propofol and thiamylal affect oxygen free radical production and intracellular calcium concentration ([Ca2+]i) in the post-ischemic reperfused heart. Forty-eight rat hearts were perfused with a Langendorff system and loaded with Fura-2 / AM as a [Ca2+]i marker. The hearts were divided into 6 groups as follows (each group: n = 8); Group S (saline), Group TL (thiamylal 100 microM), Group TH (thiamylal 300 microM), Group I (Intralipid), Group PL (propofol 3 microM), and Group PH (propofol 10 microM). All hearts were initially perfused for 5 min as control aerobic perfusion. Afterwards, no-flow ischemia was induced for 15 min, followed by reperfusion for 20 min. The formation of hydroxyl radicals in the coronary effluent was measured with high performance liquid chromatography using salicylic acid. At the beginning of the ischemia and reperfusion periods, increases in systolic and diastolic [Ca2+]i were observed in all groups except Group TH. The high dose of thiamylal significantly suppressed this initial increase in cytosolic [Ca2+]i (Group S 1.30+/-0.15; Group TL 0.99+/-0.17; Group TH 0.70+/-0.09, at 1 min after reperfusion; systolic [Ca2+]i : p < 0.05). Total DHBAs in the coronary effluent of all groups increased significantly 1 min after reperfusion, however, there were no significant differences among the groups. Clinical doses of propofol had no significant effect on myocardial function and [Ca2+]i before and after ischemia, whereas thiamylal suppressed the increase in [Ca2+]i during ischemia and reperfusion. However, free radical formation during reperfusion was unaffected by thiamylal and propofol.