Vitamin C Research Today is a free monthly online journal that collates and summarizes the latest research about Vitamin C, including details on benefits, dosage, supplements, information.

Protective effects of combined ischemic preconditioning and ascorbic acid on mitochondrial injury in hepatic ischemia/reperfusion.

Lee WY, Lee JS, Lee SM

College of Pharmacy, Sungkyunkwan University, Suwon, South Korea.

BACKGROUND: This study examined the in vivo effects of ischemic preconditioning (IPC), ascorbic acid (AA), or a combination (IPC + AA) on the level of mitochondrial injury caused by hepatic ischemia/reperfusion (I/R). MATERIALS AND METHODS: A rat liver was preconditioned with 10 min of ischemia followed by 10 min of reperfusion, and then subjected to 90 min of ischemia followed by 5 h of reperfusion. The rats were pretreated with AA (100 mg/kg, i.v.) 5 min before the sustained ischemia. RESULTS: I/R increased the aminotransferase activity and level of mitochondrial lipid peroxidation, whereas it decreased the reduced glutathione:oxidized glutathione ratio. Either the IPC or AA pretreatment alone attenuated these changes, with the effect being enhanced by IPC + AA. The level of mitochondrial glutamate dehydrogenase, which is specifically located in the matrix, decreased after I/R but this was prevented by IPC + AA. Significant peroxide production was observed after 10 min of reperfusion after sustained ischemia. This change was attenuated by either IPC or AA alone and was further attenuated by IPC + AA. The mitochondria isolated after I/R were rapidly swollen, indicating an opening of the permeability transition pore. However, this was markedly reduced by IPC + AA. The hepatic ATP level was lower after I/R, which was restored by IPC alone and IPC + AA. CONCLUSIONS: Our findings suggest that IPC and AA synergistically reduce the level of mitochondrial damage during I/R as a result of decreased postischemic oxidant stress.

Published 24 August 2007 in J Surg Res, 142(1): 45-52.
Full-text of this article is available online (may require subscription).

© 2004-2008 Vitamin C Research Today. All Rights Reserved.