An Investigation of Radiation-Induced Mitotic Inhibition in L-Strain Mouse Cells

Abstract

<p> The variation in sensitivity of L60T cells to gamma rays has been studied as a function of position in the cell division cycle. For a dose range of 0-12,000 rads, no significant variation was found for mitotic delay. Such was not the case for sensitivity to cell killing, which was found to increase as the cells passed from G1 through S to G2 of the division cycle. The results of mitotic delay are in disagreement with results published by other workers although the survival data agree with previous reports for a similar cell line. Results reported in connection with cell cycle determinations and mitotic delay suggest that the existence of a repair cycle operating concurrently with the normal cell cycle may be postulated. The theoretical treatment of mitotic delay given by Lea is examined and is not found to describe adequately the present results. Finally, the evidence reported here suggests that mitotic delay and radiation lethality are not separate manifestations of the same phenomenon. Experimental materials for further investigation into the repair processes involved are suggested.</p>