RT Book, Section
A1 Deshane, Jessy
A1 Thannickal, Victor J.
A2 Grippi, Michael A.
A2 Antin-Ozerkis, Danielle E.
A2 Dela Cruz, Charles S.
A2 Kotloff, Robert M.
A2 Kotton, Camille Nelson
A2 Pack, Allan I.
SR Print(0)
ID 1194947558
T1 Redox Signaling and Oxidative Stress in Lung Diseases
T2 Fishman’s Pulmonary Diseases and Disorders, 6e
YR 2023
FD 2023
PB McGraw-Hill Education
PP New York, NY
SN 9781260473988
LK accessmedicine.mhmedical.com/content.aspx?aid=1194947558
RD 2025/03/18
AB Molecular  oxygen  is  a  prerequisite  to  life  of  all  aerobic  organisms.  With  its  large  surface  area  and  extensive  blood  supply  the  human  lung  is  engineered  for  its  primary  function  in  gas  exchange.  While  oxygen  is  essential  for  its  many  roles  in  human  physiology,  high  concentrations  of  oxygen  or  its  metabolites,  commonly  referred  to  as  reactive  oxygen  species  (ROS),  have  the  potential  to  cause  cellular  injury  and  contribute  to  disease  pathogenesis.  The  most  damaging  forms  of  ROS  are  free  radicals.  A  free  radical,  by  definition,  refers  to  any  chemical  species  containing  one  or  more  unpaired  electrons  in  their  atomic  or  molecular  orbitals.  These  unpaired  electrons  give  considerable  reactivity  to  free  radical  species,  which  can  trigger  chemical  reactions  that  damage  cellular  constituents  of  living  organisms.  Molecular  oxygen  (dioxygen)  is  itself  a  radical  based  on  the  presence  of  unpaired  electrons  in  its  outermost  orbital;  however,  their  parallel  spin  retrains  its  reactivity.  O2  can  form  the  superoxide  anion  radical  (O2•−)  upon  addition  of  an  electron,  thus  overcoming  this  restraint  and  making  O2•−  a  highly  reactive  species.1,2  The  photodynamic  activation  of  oxygen  can  result  in  the  formation  of  singlet  oxygen,  and  its  reductive  activation  results  in  the  formation  of  hydrogen  peroxide  (H2O2)  or  the  highly  reactive  hydroxyl  radical  (•OH).3,4  When  two  free  radicals  share  their  unpaired  electrons,  nonradical  species  of  lower  reactivity  are  generated.  Thus,  ROS  constitute  both  free  radicals  and  nonradicals.