Persistence of alkylated DNA bases in the Mongolian gerbil (Meriones unguiculatus) following a single dose of methylnitrosourea

摘要: Methylated purines were determined in DNA of various gerbil tissues following a single i.v. injection N-[14C]methyl-N-nitrosourea (10 mg/kg). Enzymic removal the promutagenic base O6-methylguanine was most efficient liver, followed by kidney, lung and brain. In cerebral DNA, 40% initial concentration still present after 6 months. Since brain is apparently not susceptible to oncogenic effect methylnitrosourea related carcinogens, these data indicate that formation persistence O6-alkylguanine may constitute necessary although sufficient event for initiation organ-specific carcinogenesis monofunctional alkylating agents.