Initiation and promotion at different ages and doses in 2200 mice. II. Decrease in promotion by TPA with ageing

摘要: Using the data described in Paper I, we compare effects of same treatment timings and doses given at different ages. Initiation with DMBA 68 weeks age, followed 3 later by TPA, has a significantly (P less than 0.0001) rapid effect on subsequent tumour incidence does initiation 8 or 48 TPA. We suggested that this is chiefly due not to changes numbers cells initiated DMBA, but rather decrease promotional efficacy TPA ageing mice.