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Free Radicals

Free Radicals. April 21,2014. Free Radical Functions From W. Droge. 1.At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents 2.At moderate concentrations, however,

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Free Radicals

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  1. Free Radicals April 21,2014

  2. Free Radical FunctionsFrom W. Droge • 1.At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents • 2.At moderate concentrations, however, • nitric oxide (NO), superoxide anion, and related reactive oxygen species (ROS) play an important role as regulatory mediators in signaling processes.

  3. Free Radical Functions • 3.Many of the ROS-mediated responses actually protect the cells against oxidative stress and reestablish “redox homeostasis.” • 4. Higher organisms, however, have evolved the use of NO and ROS also as signaling molecules for other physiological functions. • 5.These include regulation of vascular tone, monitoring of oxygen tension in the control of ventilation and erythropoietin production, and signal transduction from membrane receptors in various physiological processes.

  4. Free Radical Concentrations • 6. NO and ROS are typically generated in these cases by tightly regulated enzymes such as NO synthase (NOS) and NAD(P)H oxidase isoforms, respectively. • 7. In a given signaling protein, oxidative attack induces either a loss of function, a gain of function, or a switch to a different function. • 8. In mitochondria, ROS are generated as undesirable side products of the oxidative energy metabolism.

  5. Free Radical Damage • 9. An excessive and/or sustained increase in ROS production has been implicated in the pathogenesis of cancer, diabetes mellitus, atherosclerosis, neurodegenerative diseases, rheumatoid arthritis, ischemia/reperfusion injury, obstructive sleep apnea, and other diseases. • 10. That the process of aging may result, at least in part, from radical-mediated oxidative damage was proposed more than 40 years ago by Harman (J Gerontol11: 298–300, 1956).

  6. ROS Production

  7. ROS Balance

  8. ROS

  9. Important Physiological Functions

  10. Some References • 1.De Iuliis GN, Newey RJ, King BV, Aitken RJ. Mobile phone radiation induces reactive oxygen species production and DNA damage in human spermatozoa in vitro PLoS One 2009; 4:e6446 • 2.See 20-30% changes at about 2W/kg in ROS at 1.8GHz Max of 30% Changes at 4.3W/kg • 3. DNA Damage above 2.8W/kg and up 29% at 27W/kg • 4. Do you want to carry your cell phone in your Pocket?

  11. Yakymenko I, Sidorik E, Kyrylenko S, Chekhun V. Longterm exposure to microwave radiation provokes cancer growth: evidences from radars and mobile communication systems. ExpOncol2011; 33:62 • 1. Overproduction of free radical species in embryonal cells exposed to low intensity radiofrequency radiation • Burlaka A.1, Tsybulin O.2, Sidorik E.1, Lukin S.1, Polishuk V.2, Tsehmistrenko S.2, Yakymenko I.2 • 1R.E. Kavetsky Institute of Experimental Pathology, Oncology and Radiobiology, NAS of Ukraine, Kyiv 03022, Ukraine • 2Bila Tserkva National Agrarian University, Soborna square 8/1, BilaTserkva 09117, Ukraine

  12. Burlaka A.1 Reference Shows • 1. Show increase in NO by 80% at 38 hr • And 56% at 5 days. • 2. In this set up 200µW/cm2 corresponds to SAR=0.4W/kg • 3. DeshmukhPS, Banerjee BD, Abegaonkar MP, Megha K, Ahmed RS, Tripathi AK, Mediratta PK. • Effect of low level microwave radiation exposure on cognitive function and oxidative stress in rats. Indian J BiochemBiophys 2013; 50:114 • Shows loss of memory.

  13. Spin Biochemistry Modulates Reactive Oxygen Species(ROS) Production by Radio Frequency Magnetic FieldsRobert J. Usselman1*, Iain Hill3, David J. Singel2, Carlos F. Martino 3¤*1 Electromagnetics Division, National Institute of Standards and Technology, Boulder, Colorado, United States of America, 2 PLOS ONE 2014 • The effects of weak magnetic fields on the production of reactive oxygen species • (ROS) intracellular superoxide (O2*-) and extracellular hydrogen peroxide (H2O2) • were investigated in vitro with rat pulmonary arterial smooth muscle cells (rPASMC).We observe a decrease in O2*- and an increase in H2O2 concentrations in the presence of a 7 MHz radio frequency (RF) at 10 μTRMS and static 45 μTmagnetic fields. O2*- and H2O2 production in metabolic processes is proposed to occur through singlet-triplet modulation of semiquinoneflavin (FADH*) enzymes and O2*- spincorrelated radical pairs. Spin-radical pair products are modulated by the 7 MHz RF magnetic fields that decouple flavin hyperfine interactions during spin decoherence. RF flavinhyperfine decoupling results in an increase of H2O2 singlet state products, which creates cellular oxidative stress and acts a secondary messenger that affects cellular proliferation. This study demonstrates the interplay between O2*- and H2O2 production influenced by RF magnetic fields and underscores the subtle effects of lowfrequencymagnetic fields on oxidative metabolism, ROS signaling, and cellular growth

  14. Simko, M. “Cell Type Specific Redox Status is Responsible for Diverse Electromagnetic Field Effects” General Medical Chemistry 2007,14,1141-1152

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