Decreased nucleotide content as the cause of decreased ATP synthesis in thymus nuclei after irradiation.

Abstract

SummaryIt has previously been demonstrated that re-synthesis of ATP in rat-thymus nuclei had decreased shortly after moderate doses of x-irradiation. It was concluded that nuclear oxidative phosphorylation is inhibited by x-irradiation, and this inhibition has been implicated in the mechanism leading to interphase death. In the present investigation it is demonstrated that the rates of nuclear ATP synthesis and utilization in isolated thymus nuclei are not affected by whole-body x-irradiation. Irradiation causes a loss of nucleotides from cells as well as from nuclei. The resulting decrease in ATP content can completely explain the decreased re-synthesis of ATP previously reported.