DIETARY-SUPPLEMENTS OF ANTIOXIDANTS REDUCE HPRT MUTANT FREQUENCY IN SPLENOCYTES OF AGING MICE

The level of spontaneous and gamma-radiation-induced mutations in the hypoxanthine-guanine phosphoribosyltransferase (hprt) locus as well as the decrease in frequency of these mutations in mice of various age p retreated with dietary supplements of an antioxidant mixture (vitamins C, E, beta-carotene, rutin, selenium, zinc) were studied in splenocyt es of young (8-14-week-old) and aged (102-110-week-old) male C57BL/6 m ice. The frequency of spontaneous mutations in splenocytes of 102-110- week-old mice was higher by 68-88% than that in mice aged 8-14 weeks. On gamma-irradiation (0.5-5.0 Gy) of mice, the frequency of radiation- induced mutations (Vf assay) in aged mice was 2.3 to 3.6 times (depend ing on dose) higher than in young ones. Daily supplements of an antiox idant mixture to the diet of mice prior to irradiation showed an antim utagenic effect. The values of mutant frequency reduction factor (MFRF ) for 14-110-week-old mice fed with dietary antioxidants during 6 week s prior to gamma-irradiation with doses of 2.0 and 5.0 Gy were 5.4 and 3.7, respectively. The frequency of radiation-induced mutations preve nted or not prevented by antioxidants was much higher in aged mice tha n in young ones.