Reperfusion Injury

Overview
  • Reperfusion Injury is the result of blood flow restoration to tissues which have undergone Ischemia
  • Sadly, sudden reperfusion of an ischemic tissue accelerates progression of cell injury to an irreversible stage and can substantially enhance damage following an episode of ischemia
Pathogenesis
  • Viable ischemic cells suffer from severe derangements in their membrane permeability and restoration of blood flow introduces fluid with a high level of calcium, thus potentially enhancing cytosolic calcium derangement (See: Cell Injury Biochemistry)
  • Viable ischemic cells also suffer from severe derangements in their mitochondrial function and when oxygen and nutrients are restored the damaged mitochondria appear to inappropriately generate large amounts of reactive oxygen species, thus precipitating Free Radical Cell Injury.
  • Consequently, reperfusion can lead to irreversible injury of ischemic cells which had not yet reached the irreversible threshold of damage purely from the original ischemia
  • Ultimately however, the blood flow of ischemic tissues must be restored for recovery and healing to begin
  • Indeed, methods by which blood flow can be restored to ischemic tissues while avoiding reperfusion injury is an intense focus of current biomedical research