ABSTRACT
This study was aimed to elucidate the effects of K(ATP) activation during IPC on the PKC-epsilon, NF-kappaB and AP-1 in ischemia-reperfused rat hearts. SD male rats weighting from 300 to 350 g were split into 9 groups, such as sham control (S), IPC, 3 cycles of 5 min ischemia and 5 min reperfusion, continuous preconditioning (CP), 8 cycles of 5 min ischemia and 5 min reperfusion, K(ATP) opening (KO) with pinacidil (1.0 mg/kg), K(ATP) blocking with glibenclamide (1.0 mg/kg) injection, ischemia (IS), 30 min ischemia, IPC followed by IS, 8) K(ATP) blocking and IPC followed by IS (KB+IPC+IS), IS and K(ATP) opening (KO+IS). Heart were subjected to ligation of left descending coronary artery and reperfusion in groups of IPC, CP, IS with or without IPC. Immunohistochemistry and Western blotting for PKC-epsilon, NF-kappaB and AP-1 were performed at 3, 6, 24 hours after reperfusion or treatment. Immunoreactivities against PKC-epsilon antibody were observed stronger in the groups of IPC, KO, IPC+IS and KO+IS than groups of KB, IS and KB+IPC+IS. NF-kappaB activation and translocation were only observed in the groups of including 30 min ischemia and reperfusion. AP-1 activation and translocation were opposite to the results of PKC-epsilon activation. In the group of CP, KB, IS and KB+IPC+IS, reactivities of AP-1 antibody were stronger than IPC+IS, KO+IS, and weaker in the groups of S, IPC and KO. These results suggest that K(ATP) opening with IPC or pharmacological methods may direct effect on the PKC-epsilon activation and that K(ATP) blocking has effect on the AP-1 activation and translocation in the heart of ischemiareperfused of rats.