Generation of Free Radicals during Cold Injury and Rewarming
Abstract
Cold injury is often associated with irreversible cell damage. The present study examines the mechanism of such injury. New Zealand white rabbits were anesthetized with ketamine and xylazine, and then ventilated. The femoral artery and vein were exposed. A continuous display of electrocardiogram was obtained. One leg was cooled with a freezing mixture up to 0C, which was followed by rewarming; the other leg served as control. Blood samples were withdrawn from the femoral artery for analysis of creatine kinase (CK), lactate dehydrogenase (LDH), and malonaldehyde (MDA). At the end, salicylate was injected through the femoral vein to trap any hydroxyl radical (OH) formed. Rabbits were immediately sacrificed, and biopsies were withdrawn and frozen at liquid Nitrogen temperature to analyze OH. Local blood flow in the cold-exposed leg was reduced significantly, suggesting that cold injury was associated with ischemic insult. CK and LDH were increased after cold exposure, then increased further during rewarming. MDA formation followed a similar pattern. OH generated after cooling increased significantly upon rewarming. These results indicate that rewarming is associated with an episode of ischemia/perfusion, with simultaneous generation of free radicals which, at least in part, may be responsible for cellular injury associated with rewarming. Keywords: Hypothermia. (AW)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA213088
Entities
People
- Anna George
- Dipak K. Das
- Jaisimha Lyengar
- John C. Russell
- Saswati Samanta
Organizations
- University of Connecticut Health Center