In an attempt to better understand the effects of whole body X-irradiation on the levels of non-protein sulfhydryl (NP-SH), non-protein disulfide (NP-SS) and oxygen consumption rate (QO2) of the mouse duodenum, and to clarify the possible radioprotective action of reduced glutathione (GSH), a whole body X-irradiation of 1,000r was given to albino mouse either singularly or immediately after injecting GSH intraperitoneally to mouse 1 mg per gm of body weight. NP-SH was measured by Ellman s method, NP-SS was measured by the electrolytic reduction method described by Dohan and Woodward, and (QO2) by the Warburg s standard manometric method. The experiment was performed at 1, 6, 12 and 24 hours post-irradiation, and the comparison was made with the control. The results thus obtained are summarized as follows: 1) Comparing with the intrinsic NP-SH level of 3.31±0.27μ mol/gm wet weight in the duodenum of the normal mouse, either whale body X-irradiation or injection of GSH alone produced no significant change in NP-SH from the normal. However, when GSH was injected prior to X-irradiation, markedly elevated NP-SH levels were observed throughout the entire experiment with the highest value of 4.70±0.10 at 6 experimental hours. 2) The normal value of NP-SS in the mouse duodenum was 1.57±0.17μ mol/gm wet weight, while in the group where injection of GSH and X-irradiation were combined, NP-SS increased to 2.36±0.33 at 12 hours and 2.15±0.53 at 24 hours, showing the intermediate value between the GSH injection group and X¡¤irradiation group. 3) The normal value of (QO2) was 4.16±0.73μl O2/hr./gm D.W., and no noticeable change was observed comparing with the GSH injection group. However, in the group where X¡¤irradiation alone was given, (QO2) of the duodenum increased significantly throughout the entire experiment with the highest value of 6.35±1.07 at 6 experimental hours. When GSH was injected before X-irradiation was given, the levels of (QO2) were in the middle of the GSH injection group and X-irradiation group. 4) The above results suggest that GSH may be effective as a radioprotector in terms of NP-SH, NP-SS and (QO2) of the mouse duodenum.
