The Use of Chromium-51 as a Sensitive Quantitative Criterion of Early Radiation Damage to Rat Thymocytes

Abstract

The uptake of Crsl-chromate by thymocytes in suspension can be used as a sensitive quantitative criterion for the evaluation of early radiation damage to these cells, often under situations where other methods of assessing cell death such as morphological changes do not yield valid results. 'I'he development of a radiation lesion is characterized by a reduction in the uptake of Cr5l, which in vitro can be detected 1 hour following irradiation and with doses as low as 25 rads. By means of this technique thymocytes have been shown to be completely protected by anoxia to doses of up to 150 rads, but a t higher levels anoxia affords little protection. No protection of thymocytes could be demonstrated in vivo with S,P-aminoethylisothiouronium bromide hydrobromide (AET) or serotonin a t 0.72 mmoles per kg. L-Cysteine, cysteamine, and serotonin a t 1 m M concentration in vitro showed no protection of thymocytes provided they were removed from the cells iminediately subsequent to irradiation.

The Ehrlich Ascites Carcinoma as a Tool for the Rapid Evaluation of the Efficacy of Radioprotective Compounds at the Cellular Level

“…During the course of this work it was observed that certain compounds in concentrations of 10-20 m M were highly toxic to Ehrlich ascites cells as measured by their subsequent growth, if left in coiltact with them for periods of time as short as 30 minutes. Similar findings have been reported for thymocytes in earlier work (20) and for embryonic heart cells (21) and strain-L mouse fibroblasts (22). Consequently all cell Can.…”

Influence of Oxygen Tension on X-ray-induced Fall in Anodic Mobility of Ehrlich Ascites Tumour Cells Irradiatedin Vitro

“…cells is thus markedly enhanced by raising the oxygen tension over a range where no further effect on nuclear damage is observed . Oxygen enhancement ratios higher than those observed in cell survival and nuclear damage studies have been reported for radiation-induced changes in other membrane parameters (Scaife and Vittorio 1964, Watkins 1970, Cramp, Watkins and Collins 1972 . The evidence to date supports Alper's theory that biological membranes are major sites for the oxygen effect.…”

A STUDY OF THE EFFECTS OF X-IRRADIATION AND PROTECTIVE AGENTS ON MICE USING Cr51

“…Cra studies on a cellular basis have already been carried out. I t was found that Cr51 uptalte by thymocytes is an active cellular uptake depending upon the integrity of the cell and that the uptake of Cr51 chromate by thymocytes in suspension can be used as a sensitive quantitative criterioil for the evaluation of early radiation damage to these cells (13). Other studies are in progress in an attempt to determine the early and late effects of Xirradiation and protective compounds on cell suspensions (i.e.…”