DNA-BASE DAMAGE GENERATED IN-VIVO IN HEPATIC CHROMATIN OF MICE UPON WHOLE-BODY GAMMA-IRRADIATION

MORI T HORI Y DIZDAROGLU M

T. Mori et al., DNA-BASE DAMAGE GENERATED IN-VIVO IN HEPATIC CHROMATIN OF MICE UPON WHOLE-BODY GAMMA-IRRADIATION, International journal of radiation biology, 64(6), 1993, pp. 645-650

33

INGLESE

Article

Radiology,Nuclear Medicine & Medical Imaging","Nuclear Sciences & Tecnology

International journal of radiation biology → ACNP

0955-3002

64

6

1993

645 - 650

ISI

0955-3002(1993)64:6<645:DDGIIH>2.0.ZU;2-F

DNA base lesions in hepatic chromatin formed upon whole-body irradiati on of mice were studied. After gamma-irradiating (20-470 Gy) and killi ng animals, chromatin was isolated from their livers and analysed by G C-MS. Five pyrimidine- and five purine-derived DNA lesions were identi fied and quantified. These were 5-hydroxy-5-methylhydantoin, 5-hydroxy cytosine, 5-(hydroxymethyl)uracil, 4,6-diamino-5-formamidopyrimidine, 7,8-dihyro-8-oxoadenine, 2-hydroxyadenine, 2,6-diamino-4-hydroxy-5-for mamidopyrimidine, 7,8-dihydro-8-oxoguanine, thymine glycol and 5,6-dih ydroxyuracil. Except for the latter two, the amounts of these compound s were increased significantly over control levels in the dose range o f 100-470 Gy. Above 200 Gy, a deviation from linearity was observed, a lthough the yields were increased in most cases up to 470 Gy. The modi fied bases that were identified are typically produced by hydroxyl rad ical attack on the DNA bases. This may indicate a role for hydroxyl ra dicals in their formation in vivo. These lesions may play a role in th e biological consequences of ionizing radiation such as mutagenesis an d carcinogenesis.