PT  - JOURNAL ARTICLE
AU  - Qun Chen
AU  - Charles L. Hoppel
AU  - Edward J. Lesnefsky
TI  - Blockade of Electron Transport before Cardiac Ischemia with the Reversible Inhibitor Amobarbital Protects Rat Heart Mitochondria
AID  - 10.1124/jpet.105.091702
DP  - 2006 Jan 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 200--207
VI  - 316
IP  - 1
4099  - http://jpet.aspetjournals.org/content/316/1/200.short
4100  - http://jpet.aspetjournals.org/content/316/1/200.full
SO  - J Pharmacol Exp Ther2006 Jan 01; 316
AB  - Cardiac ischemia damages the mitochondrial electron transport chain. Irreversible blockade of electron transport at complex I by rotenone decreases ischemic damage to cardiac mitochondria by decreasing the loss of cytochrome c and preserving respiration through cytochrome oxidase. Therapeutic intervention to protect myocardium during ischemia and reperfusion requires the use of a reversible inhibitor that allows resumption of oxidative metabolism during reperfusion. Amobarbital is a reversible inhibitor at the rotenone site of complex I. We asked whether amobarbital administered immediately before ischemia protected respiratory function. Isolated rat hearts were perfused for 15 min followed by 25-min global ischemia at 37°C. Amobarbital-treated hearts received drug for 1 min before ischemia. Subsarcolemmal (SSM) and interfibrillar (IFM) populations of mitochondria were isolated after ischemia, and oxidative phosphorylation was measured. Amobarbital protected oxidative phosphorylation, including through cytochrome oxidase, in both SSM and IFM in a dose-dependent manner, with an optimal dose of 2 to 2.5 mM. Amobarbital also preserved cytochrome c content in both SSM and IFM. Thus, reversible blockade of the electron transport chain during ischemia protects mitochondrial respiration. The American Society for Pharmacology and Experimental Therapeutics