The Cytotoxic Action of Irradiated Histidine on Rat Thymocytes in Vitro

Summary

The effects of irradiated histidine on the survival of isolated rat thymocytes were studied. Incubation of unirradiated thymocytes with the histidine irradiated with γ-rays over a range of 8 to 204 krads in Krebs-Ringer's solution caused an increase in the death-rate of cells, as measured by erythrosin-B staining. Based on comparative studies on cytotoxic abilities with special reference to sulphydryl reactivity between irradiated histidine and N-ethylmaleimide, a sulphydryl reagent, it is suggested that intracellular sulphydryl groups are involved in some mechanism of cell death after treatment of cells with the irradiated histidine.