Effect of continuous infusion of bleomycin on repopulation in mouse lip mucosa during fractionated irradiation.

Abstract

The effect of the administration of bleomycin on repopulation in mouse lip mucosa during fractionated irradiation was studied. Two equal-sized irradiation fractions were delivered with 1-, 7-, or 10-day intervals, with and without simultaneous administration of 40 mg bleomycin/kg in a continuous sc infusion, given over 7 days. In the experiments with irradiation only, the prolongation of the interval from 1 day to 7 days resulted in a net increase of the isoeffective dose due to compensatory proliferation. This effect was even more pronounced with the 10-day treatment interval. The addition of bleomycin, however, nearly completely suppressed this proliferative activity.