The effect of aging and interval between primary and secondary treatment in two-stage carcinogenesis on mouse skin.
Two-stage carcinogenesis experiments on mouse skin (female ICR/Ha Swiss mice) were done by initiating mice at three age levels (6, 44, and 56 weeks) and promoting after a 2-week interval. In another series, mice were initiated at age 6 weeks, and three time intervals (2, 36, and 56 weeks) were used between initiation and promotion. The initiating agent was 7, 12-dimethylbenz(a)anthracene and the promoting agent was phorbol myristate acetate in all experiments. The results showed a general decrease in tumor production with increasing age at the time of promotion. However, the initiating effect persisted even when the interval between initiation and promotion was 56 weeks.
D000375:Aging; D000438:Alcohols / Q000008:administration & dosage; D000818:Animals; D001551:Benz(a)Anthracenes / Q000008:administration & dosage; D002273:Carcinogens / Q000008:administration & dosage; D004224:Diterpenes / Q000008:administration & dosage; D005260:Female; D051379:Mice; D008813:Mice, Inbred ICR; D009374:Neoplasms, Experimental / Q000139:chemically induced; D012878:Skin Neoplasms / Q000139:chemically induced*; D013997:Time Factors
D000438:Alcohols; D001551:Benz(a)Anthracenes; D002273:Carcinogens; D004224:Diterpenes