Oxygen Free Radicals and Ischaemic Preconditioning in the Brain: Preliminary Data and a Hypothesis

Chemical preconditioning effect of 3-nitropropionic acid in anesthetized rat heart

“…The ROS burst, which peaks 3 h after 3-NP (Wiegand et al, 1999;Brambrink et al, 2000), is generated upstream of SDH and may be direct result of respiratory chain inhibition (Garcia-Ruiz et al, 1995;Brambrink et al, 2000), or alternatively, from an indirect excitotoxic pathway (Kim et al, 2000;Brambrink et al, 2000). Furthermore, the abolition of tolerance by free radical scavenger, dimethylthiourea, strongly suggests that ROS generation may be a necessary step in the establishment of ischemic preconditioning (Schumann et al, 1999). In addition, there is accumulating evidence indicating that moderate ROS levels can regulate cellular functions including signaling cascades and transcriptional/ post-transcriptional control of gene expressions (Garnier et al, 2002).…”

Short-Time Intermittent Preexposure of Living Human Donors to Hyperoxia Improves Renal Function in Early Posttransplant Period: A Double-Blind Randomized Clinical Trial

“…For the following reasons, oxygen-free radicals (OFRs) may present a common signal in ischemic tolerance (IT) induction: (1) the majority if not all of published tolerance inducing stimuli are associated with the production of OFR; (2) induction of antioxidant enzymes has been shown for many IT protocols; (3) OFR itself may induce IT [ 42 ].…”