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.
Radiation Safety Group, Central Research Institute of Electric Power Industry, Tokyo, Japan.
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Yamaoka
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Sato
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Utsumi
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