RESUMO
This work was devoted to investigation or repair regulation by biological factors: viruses and interferon. DNA damage induced by gamma- and UV-irradiation, ethyleneimine and 4-nitro-quinoline-1-oxide (4-NQO) were studied, by sedimentation of lysed cells through alkaline sucrose gradients, by hydroxylapatite column chromatography and by the chromosomal aberration test. The reproducible vaccinia virus resulted in simulation repair activity of chick embryo cells after treatment with 4-NQO. Interferon, added after gamma- and UV-irradiation, decreased the chromosomal aberration level, stabilized it after ethyleneimine treatment and also stimulated the ability of cells to rejoin DNA breaks induced by 4-NQO. The cause of this phenomenon is discussed.
Assuntos
Transformação Celular Viral , Aberrações Cromossômicas , Reparo do DNA , Interferons/farmacologia , Vaccinia virus , Animais , Linhagem Celular , Embrião de Galinha , Aberrações Cromossômicas/efeitos dos fármacos , Cromossomos/efeitos dos fármacos , Cromossomos/efeitos da radiação , Reparo do DNA/efeitos dos fármacos , Embrião de Mamíferos , Camundongos , Camundongos Endogâmicos CBA , RatosRESUMO
We studied the effect of cadmium chloride on: (1) the DNA of human cells; (2) the mutagenic effect of reproducing Kilham virus; (3) the synthesis of virus-induced interferon, and (4) the reproduction of oncogenic (mammalian leucosis) virus. Cadmium chloride caused degradation of DNA in human- and rat-embryo cells. Culture infected by the virus in the presence of cadmium sulphate had the highest yield of cells with chromosomal aberrations. Cadmium chloride caused marked inhibition of the virus-induced synthesis of interferon. The introduction of cadmium chloride into diploid cells infected by the leucosis virus caused a 3-4 fold increase in the yield of virus-induced transformation foci.