Induction of two species of superoxide dismutase in some organs of rats by low dose X-irradiation.
Four hours after 0.25 Gy X-irradiation, the enzymatic activity of copper and zinc activated superoxide dismutase (Cu/Zn-SOD) in the spleen of mature rats showed a significant quantitative increase (by 25%); this was accompanied by a marked increase (by 70%) in the mRNA for this enzyme as compared to the control (sham irradiation) group. Irradiation had no effect on the enzymatic activity of manganese activated superoxide dismutase (Mn-SOD). Moreover, the expression of the mRNA for Mn-SOD was similar to that of the unirradiated control group. On the other hand, the enzymatic activity of both Cu/Zn-SOD and Mn-SOD in the liver of fetal rats showed a significant quantitative increase (by 15-35%); the expression of the mRNA for the two species of SOD increased (by 20-30%) at 4 hours after 1 Gy X-irradiation as compared to the control group. These findings suggest that the increase in SODmRNA level is due to novel transcription of SODmRNA by low dose irradiation.
Yamaoka
K
K
Radiation Safety Group, Central Research Institute of Electric Power Industry, Tokyo, Japan.
Sato
E F
EF
Utsumi
K
K
D000818:Animals; D015152:Blotting, Northern; D003593:Cytoplasm / Q000201:enzymology; D004307:Dose-Response Relationship, Radiation; D004790:Enzyme Induction / Q000528:radiation effects; D005260:Female; D005333:Fetus; D015870:Gene Expression / Q000528:radiation effects*; D007527:Isoenzymes / Q000096:biosynthesis*; D008099:Liver / Q000196:embryology / Q000201:enzymology / Q000528:radiation effects; D008297:Male; D008928:Mitochondria / Q000201:enzymology; D008930:Mitochondria, Liver / Q000201:enzymology; D009928:Organ Specificity; D010053:Ovary / Q000201:enzymology; D011247:Pregnancy; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000201:enzymology* / Q000528:radiation effects; D013482:Superoxide Dismutase / Q000096:biosynthesis*; D014965:X-Rays
D007527:Isoenzymes; D012333:RNA, Messenger; D013482:Superoxide Dismutase