Molecular basis for tumor necrosis factor-induced increase in pulmonary superoxide dismutase activities.
Tracheal insufflation of tumor necrosis factor (TNF) enhances pulmonary antioxidant enzyme activities and protects rats against oxygen toxicity (J. Appl. Physiol. 68: 1211-1219, 1990). We now report that tracheal insufflation of TNF selectively induced pulmonary Mn-superoxide dismutase (SOD) mRNA in normoxia- and hyperoxia-exposed rats, leading to increased amounts of Mn-SOD specific protein and enzyme activity. Tracheal insufflation of TNF had no effect on the levels of pulmonary Cu,Zn-SOD mRNA or specific protein. Hyperoxia alone also selectively induced pulmonary Mn-SOD mRNA. However, the hyperoxia-induced increase in Mn-SOD mRNA was not associated with an increase in Mn-SOD specific protein or enzyme activity. The results suggest that the increased pulmonary Mn-SOD in TNF-insufflated rats may contribute to the TNF-induced protection against oxygen toxicity.
Tsan
M F
MF
Research Service, Department of Veterans Affairs Medical Center, Albany, New York.
White
J E
JE
Treanor
C
C
Shaffer
J B
JB
D000818:Animals; D007527:Isoenzymes / Q000235:genetics; D007700:Kinetics; D008168:Lung / Q000187:drug effects / Q000201:enzymology* / Q000473:pathology; D008297:Male; D010100:Oxygen / Q000633:toxicity; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D011994:Recombinant Proteins / Q000494:pharmacology; D012016:Reference Values; D013482:Superoxide Dismutase / Q000235:genetics*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007527:Isoenzymes; D012333:RNA, Messenger; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D013482:Superoxide Dismutase; D010100:Oxygen