Abstract
Mice were given whole-body gamma-irradiation with 300 and 800 rad 1 hour or 1 day after the administration of 3H-thymidine. The time-course of the specific activity of DNA in thymus and spleen and the release of radioactivity into the fraction of DNA soluble in 0-14 N NaCl were determined for 28 hours after exposure. The results indicate that on average the loss of mitotically-active cells was delayed compared with the loss of a representative fraction of non-dividing cells. This suggested that different mechanisms might be implicated in the dying process of the dividing and non-dividing lymphoid cells. Using a dose-fractionation method, the total activity of DNA was determined in thymus and spleen at 24 hours after the first exposure and 25 hours after the in vivo labelling of DNA. A parallelism has been found between the results of this experiment and the recovery effect of the Elkind-Sutton type. It may be concluded that the dying process responsible for the loss of the dividing cells from thymus and spleen after irradiation probably involves reproductive death.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call