방사선조사에 따르는 Ribonuclease 활성 및 핵산량변동에 대하여

Abstract

were divided into 5 groups, each consisting of 6 rats. Four groups of animals were whole•body Xirradiated with the respective doses of 400 r, 600 r, 700r, and 800r. Animals were killed with the control group 24 hours after whole-body X-irradiation and examined the variation of content of nucleic acids of splenic tissue, and assayed the alkaline and acid RNase activities of spleen and serum alkaline RNase activity. The following results were obtained. 1. There was no marked change of the activity of splenic alkaline and acid RNase and of serum alkaline RNase with the dose of 400 r, comparing to normal value. 2. The activity of splenic alkaline RNase was lowered around 30% with the doses of 700 rand 800r , while that of splenic acid RNase was increa一 sed 17% with the 600 r dose , but decreased 20% and 40% respectively with 700 rand 800 r doses. 3. The serum alkaline RNase activity was incr一 eased 23% with 600 r but decreased 25% and 35% respectively with 700 rand 800 r doses. 4. No distinct variation of the spleen RNA content was observed with the low dose of 400 r. But the RNA content of spleen was decreased slightly but steadily with increasing doses of irradiation. The spleen DNA content was decreased 10%, 27%, and 33%, respectively with the doses of GOO r , 700r and 800 r. Thus the effect of whole-body X•irradiation was much more marked on DNA than RNA in the spleen. 6. The significance of variation of RNase activity was discussed.