Abstract: | Hypoxanthine in vitro causes death of thymocytes and concurrent intranucleosome degradation of chromatin. This process is more manifest in a more radiosensitive thymocyte fraction and prevented by protein synthesis inhibitors. The increase in the yield of hypoxanthine after the effect of lympholytic agents of different nature is not the result of cell death. It is assumed that hypoxanthine, formed in the exposed cells, may be an additional cytotoxic factor on reaching a subliminal concentration. |