Rat lung antioxidant enzyme activities and their specific proteins during hyperoxia.
The hyperoxia-induced increases in the activity of lung glucose-6-phosphate dehydrogenase (G-6-P) and glutathione reductase (GR) after exposure of rats to greater than 97% O2 for 6 days were accompanied by equivalent increases in the amount of the respective immunoreactive proteins. Hyperoxia also increased lung glutathione (GSH) + oxidized glutathione (GSSG) content and the magnitude of this hyperoxic response of increased GSH + GSSG, G-6-P, and GR (maximal 1.3- to 1.8-fold) declined as a function of age during the first 3 wk of life. Fetal rat lung explants cultured 4 days in 95% O2 showed increased G-6-P and GR activity and increased levels of the specific proteins 1.5-fold those of explants at 2 days of culture. We conclude that the hyperoxic response of increased rat lung G-6-P and GR activity in vivo and in vitro involves not just alteration of enzyme activity but also specific increases in the proteins catalyzing the reactions.
Crouch
L S
LS
Department of Pediatrics, University of Texas Health Science Center, Dallas 75235.
Prough
R A
RA
Kennedy
K A
KA
Snyder
J B
JB
Warshaw
J B
JB
D000375:Aging; D000818:Animals; D015153:Blotting, Western; D005954:Glucosephosphate Dehydrogenase / Q000032:analysis / Q000378:metabolism*; D005978:Glutathione / Q000378:metabolism; D005980:Glutathione Reductase / Q000032:analysis / Q000378:metabolism*; D008099:Liver / Q000201:enzymology; D008168:Lung / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D009924:Organ Culture Techniques; D010100:Oxygen / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling
D005954:Glucosephosphate Dehydrogenase; D005980:Glutathione Reductase; D005978:Glutathione; D010100:Oxygen