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B is a critical element in the antiapoptotic effect of anesthetic preconditioningDepartments of 1Internal Medicine, Division of Cardiovascular Medicine, and 2Anesthesiology and Pain Management, University of California, Davis; and 3Cardiology Section, Department of Veteran Affairs, Northern California Health Care System, Mather, California; and 4Department of Anesthesiology and Pain Medicine, University of Alberta, Edmonton, Alberta, Canada
Submitted 11 December 2008 ; accepted in final form 19 March 2009
Anesthetic preconditioning (APC), defined as brief exposure to inhalational anesthetics before cardiac ischemia-reperfusion (I/R), limits injury in both animal models and in humans. APC can result in the production of reactive oxygen species (ROS), and prior work has shown that APC can modify activation of NF-
B during I/R, with consequent reduction in the expression of inflammatory mediators. However, the role of NF-
B activation before I/R is unknown. Therefore, these experiments tested the hypothesis that APC-induced ROS results in activation of NF-
B before I/R, with consequent increased expression of antiapoptotic proteins such as Bcl-2 and decreased apoptosis. Experiments utilized an established perfused heart rat model of sevoflurane APC and I/R. The role of NF-
B was defined by a novel method of transient inhibition of the regulatory kinase IKK using the reversible inhibitor SC-514. In addition to functional measures of left ventricular developed and end-diastolic pressure, phosphorylation of I
B
and activation of NF-
B were measured along with cytosolic protein content of Bcl-2, release of cytochrome c, and degradation of caspase-3. APC resulted in ROS-dependent phosphorylation of I
B
and activation of NF-
B before I/R. APC also increased the expression of Bcl-2 before I/R. In addition to functional protection following I/R, APC resulted in lower release of cytochrome c and caspase-3 degradation. These protective effects of APC were abolished by transient inhibition of I
B
phosphorylation and NF-
B activation by SC-514 followed by washout. ROS-dependent activation of NF-
B by APC before I/R is a critical element in the protective effect of APC. APC reduces apoptosis and functional impairment by increasing Bcl-2 expression before I/R. Interventions that increase NF-
B activation before I/R should protect hearts from I/R injury.
nuclear factor-
B; reactive oxygen species
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