Fig. 2
From: Follicular Fluid redox involvement for ovarian follicle growth
Endogenous production of superoxide. Electrons generated in mitochondria, endoplasmic reticulum and cell membrane electron transport chains, and oxidation catalyzed by a diversity of enzymes, partially reduce oxygen into superoxide anion (O2 •–,); this is dismutated by superoxide dismutase (SOD) into O2 and H2O2; metal mediated catalysis of H2O2 originates the strongly reactive hydroxyl radical (HO•). When targeting biomolecules, the three oxidants, as well as many other resulting from the catalytic action of xanthine oxidase, cyclooxygenases and lipoxygenases, nitric oxide synthase, norepinephrine breakdown and autoxidation processes, enlarge the diversity of oxidants and cause biomolecule damage (reviewed in ref. [43])