Effect of Single or Fractionated X-Irradiation on the NP-SH and NP-SS of Rabbit Liver and Lung Tissues

단회(單回) 및 분획(分劃) X선(線) 조사(照射)가 가토(家兎)의 간(肝) 및 폐조직(肺組織)의 NP-SH 및 NP-SS에 미치는 영향(影響)

In view of the importance of sulfhydryl groups in producing a chemical protection against ionizing radiation, an attempt was made to evaluate the changes of intrinsic non-protein sulfhydryl (NP-SH) and non-Protein disulfide(NP-SS) of the lung and liver tissues of rabbits following the whole body X-irradiation with 900 r either in single or fractionated $(300\;r{\times}3)$ dose. NP-SH was measured by Ellman's method, and NP-SS was measured by the electrolytic reduction method described by Dohan. Experiment was performed at 1,3,5,24 and 48 hours post·irradiation, and the results were compared with the control. The results thus obtained are summarized as follows; 1) Intrinsic levels of NP-SH and NP-SS of normal rabbits were $0.77{\pm}0.10$ and $0.61{\pm}0.07\;{\mu}mol/gm$ wet weight in liver, and $0.28{\pm}0.03$ and $0.54{\pm}0.03$ in lung tissues respectively. 2) NP-SH of liver after single X-irradiation showed no significant change in general, but at 48 hours post·irradiation, it was elevated comparing with the normal value. 3) Levels of NP-SS in liver was decreased than the normal value in the irradiated groups, and the lowest level was observed at 3 hours after single X-irradiation and at 5 hours after fractionated irradiation. 4) In lung tissues, levels of NP-SS showed no significant change from the control at earlier experimental hours, but a great decrease was observed at later Part of the experiment.