自由基 Free Radicals：自由基引起的损伤 Injury induced by free radicals

Free radicals: Injury induced by free radicals

Free Radicals: Injury induced by free radicals O2

(1)Free radical Free radical--atoms, molecules or ions with unpaired electrons on an otherwise open shell configuration These unpaired electrons are usually highly reactive, so radicals are likely to take part in chemical reactions 1)Oxygen free radical 2 Lipid radical

(1) Free radical Free radical——atoms, molecules or ions with unpaired electrons on an otherwise open shell configuration. These unpaired electrons are usually highly reactive, so radicals are likely to take part in chemical reactions. 1)Oxygen free radical 2)Lipid radical

(2)Oxygen free radical, OFR Types (1)the superoxide anion(O2) (2 the hydroxyl radical (oH (3 singlet oxygen (102) (4 hydrogen peroxide(H2O2)

(2) Oxygen free radical, OFR Types： (1)the superoxide anion (O2 -) (2)the hydroxyl radical (OH ·) (3)singlet oxygen (1O2 ) (4)hydrogen peroxide (H2O2 )

(3)Lipid free radicals; The interaction of oxygen free radicals with polyunsaturated fatty acids in the phospholipids of cell membrane leads to the formation of lipid free radicals Types 1) Fatty acid radical (lL 2)Lipid peroxide (LOO) (4)Others: Cl, CH3 NO

(3) Lipid free radicals： The interaction of oxygen free radicals with polyunsaturated fatty acids in the phospholipids of cell membrane leads to the formation of lipid free radicals. Types： 1) Fatty acid radical (L·) 2) Lipid peroxide（LOO·） (4) Others: Cl·, CH3·, NO·

(5)Generation and elimination of oxygen free radicals 1)Origin of"2: a mitochondria b. Oxidation of some chemicals in body. C Catalysis by enzymes d stimulation of cells with toxins

(5) Generation and elimination of oxygen free radicals 1) Origin of O·- 2： a. Mitochondria b. Oxidation of some chemicals in body. c. Catalysis by enzymes d. Stimulation of cells with toxins

(6)Generation of OFR 02+8 02+28+2H+ byte Cytochrome aa3 02+30+3H—Ho。+H2 H202 02+4+4H+—2出20 SOD, Superoxide dismutase

(6) Generation of OFR O2 + e O2 • O2+ 2e + 2H+ H2O2 H2O2 O2 + 3 e + 3H+ HO• +H2O O2 + 4 e + 4H+ 2 H2O Cytaa3 SOD SOD, Superoxide dismutase Cytochrome aa3

Haber-Weiss reaction(without Fe+3 2·+20202+0H+0H SLOW hydroxyl radical; ferrum

Haber-Weiss reaction (without Fe+3 ) O2 －• + H2O2 O2 + OH +OH• SLOW hydroxyl radical; ferrum

Fenton -haber -Weiss reaction +3 02°+202=02+0+0 FAST

Fenton-Haber-Weiss reaction Fe+3 O2 － + H2O2 O2 + OH +OH• FAST •

(6)Elimination of oxygen free radicals )Small MW scavenging agents Dihydrocoenzyme‖l Cysteine, Vit C, glutathione moyes Atocnondion Smoth vitE、VitA

(6) Elimination of oxygen free radicals 1）Small MW scavenging agents Dihydrocoenzyme II Cysteine, Vit C, glutathione Vit E、 Vit A

2) Enzymatic scavenging agents Catalase (CAT) Superoxide dismutase MnSOD)( CuZnSOD ardelt McroRie Peroxydase (H2O2)

2）Enzymatic scavenging agents Catalase (CAT) Peroxydase （H2O2） Superoxide dismutase MnSOD CuZnSOD