Radioprotective Action of SH Compounds Ⅱ. Effect of Glutathione on the Mitotic Delay Induced by X-Ray.

The radioprotective action of GSH was studied at the cytological level using the mitotic index of Ehrlich ascites tumor cells. 1. In the irradiation with 100 or 200 rads, the rate of recovery of mitotic index in the treated with 30 mg GSH was similar to that in the control group. But 12 hours after the irradiation and on, the mitotic index increased more than the value of the control. 2. With 400 or 600 rads, the recovery of the mitotic indez was accelerated by the pretreatment with 30 mg GSH. 3. Irradiation with 400 rads 30 minutes, 3 hours and 6 hours after administration of 30 mg GSH resulted in the fastest recovery of mitotic index in the group where GSH was given 30 minutes before irradiation, followed by the group given GSH 6 hours previously. 4. Of the administration of GSH (30 mg) at 30 minutes, 3 hours, 6 hours and 9 hours aftei irradiation with with 400 rads the one that gave the most intense inhibition that 3 hours after irradiation. A slight inhibition was senn when administered at 9 hours after irradiation. 5. Treatment with GSH alone induced a slight decrease in the mitotic index and later a marked increase at 9 to 12 hours. On the basis of these date, the mechanisms of the radioprotective action of GSH were discuseed.