Effect of radioprotective agent onchromatin radiolysis

1
Effect of radioprotective agent on chromatin
radiolysis
Preoteasa V., Mihalache D., Costache A.,
Radulescu I.
Victor Babes National Institute of Pathology,
Bucharest, ROMANIA
Normal tissue chromatin (Wistar rat liver) and
tumoral tissue (Walker tumor) were irradiated by
an excimer laser IOFAN 1701, with a wavelength of
248 nm, in different doses up to 3 Mj/m2. The
irradiated chromatin samples, either simple or
dyed with proflavine dye (444 nm), were studied
by spectrophotometrical methods such as thermal
transition, absorbtion spectra (proflavine), the
red-sift spectra effect (proflavine). To study
the radioprotective role we used sodium
thyoglycolate. The conclusion is that
ultraviolet laser, directly or indirectly,
produces single and double straind breaks of the
DNA chain, as wells as changes in nuclear
proteins. Radiolithical effects are more obvious
in the case of tumoral chromatin, than in that of
normal chromatin. If, before irradiation, the
chromatin samples were added with sodium
thyoglycolate, a decrease of the lasers
destructive effects was noticed. This
radioprotector acts indirectly, by scavenging the
radicals formed in the solvent after irradiation.
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