Figure 1.

Biochemical mechanisms leading to the prevention of reperfusion injury in diving mammals. Ischemia/reperfusion events are associated with oxidative stress and inflammation in humans but are well tolerated by diving mammals. The mechanisms marine mammals use to prevent inflammation and oxidative stress derived from diving-induced ischemia and hypoxemia are still under investigation but likely include upregulation of genes involved in antioxidant defense and hypoxia tolerance via preconditioning-like responses that involve activation of the transcription factors Nrf2 and HIF-1.