Hydrogen peroxide in the human body

Abstract

Hydrogen peroxide (H 2 O 2 ) is widely regarded as a cytotoxic agent whose levels must be minimized by the action of antioxidant defence enzymes. In fact, H 2 O 2 is poorly reactive in the absence of transition metal ions. Exposure of certain human tissues to H 2 O 2 may be greater than is commonly supposed: substantial amounts of H 2 O 2 can be present in beverages commonly drunk (especially instant coffee), in freshly voided human urine, and in exhaled air. Levels of H 2 O 2 in the human body may be controlled not only by catabolism but also by excretion, and H 2 O 2 could play a role in the regulation of renal function and as an antibacterial agent in the urine. Urinary H 2 O 2 levels are influenced by diet, but under certain conditions might be a valuable biomarker of`oxidative stress'. ß

Mechanisms of H2O2-induced oxidative stress in endothelial cells

“…The overall goal of these studies is to provide a possible model for disease development within the vasculature. This is further supported by studies suggesting increased local levels of hydrogen peroxide upwards of 100 µmol/L at inflammatory sites (Halliwell et al 2000); this could have important implications for atherosclerosis, an inflammatory disease.…”

“…This dissertation focuses on the initial development of a model utilizing hydrogen peroxide (H 2 O 2 )-induced oxidative stress to mimic cardiovascular disease. The model focuses on atherosclerosis, an inflammatory disease (Ross 1999b), associated with increased local levels of H 2 O 2 (Halliwell et al 2000).…”

Free Radicals: Properties, Sources, Targets, and Their Implication in Various Diseases

“…It can easily penetrate the biological membranes. H 2 O 2 has no direct effect on DNA but can damage DNA by producing hydroxyl radical (OH -) in the presence of transition metal ions [32]. The major antioxidant enzymes that can eliminate the H 2 O 2 include catalase, glutathione peroxidase and peroxiredoxins [33,34].…”

Redox homeostasis and age‐related deficits in neuromuscular integrity and function

“…H 2 O 2 has been suggested to be a redox signalling molecule93 that can interact with redox‐sensitive components or pathways, activating various transcription factors in skeletal muscle 94. In addition to SOD‐dependent production of H 2 O 2 , a number of enzyme systems also generate H 2 O 2 including NOX4,95, 96 urate and amino acid oxidases 97. Moreover, recent evidence supports endoplasmic reticulum (ER) H 2 O 2 generation in vivo 98 via thiol‐disulfide exchange mechanisms 99.…”