ABSTRACT
The method for determination of single-strand breaks (SSB) in DNA by the technique of alkaline unwinding and hydroxylapatite chromatography has been applied for cell nuclei from organs of mice. Male mice were given methyl methane-sulfonate (MMS) and dimethylsulfoxide (DMSO) by i.p. administration. Cell nuclei were prepared from various organs and then lysed in alkali. The amount of DNA was determined by fluorometry using 4',6-diamidino-2-phenylindole.2HCl. The relative level of SSB in DNA was determined in various organs (liver, kidney, lung, spleen, testis and brain) 1-24 h after administration of the agent. After MMS-treatment the number of SSB in DNA increased to about the same extent in all organs 1 h post-treatment but then decreased by time. The SSB persisted for the longest time in brain- and lung-DNA. DMSO induced SSB only in DNA of kidney.
Subject(s)
Cell Nucleus/metabolism , DNA, Single-Stranded/analysis , Dimethyl Sulfoxide/toxicity , Methyl Methanesulfonate/toxicity , Animals , Cell Nucleus/drug effects , Cell Nucleus/radiation effects , Hydrogen-Ion Concentration , Kinetics , Male , Mice , Mice, Inbred Strains , Nucleic Acid Denaturation , Organ SpecificityABSTRACT
Styrene and its metabolite styrene oxide were given i.p. to mice. The induction of single-strand breaks (SSB) in DNA was studied with the DNA unwinding technique. The level of SSB in kidney-DNA was a linear function of the dose for both substances. Styrene and styrene oxide induced an increase in the level of SSB in DNA of kidney, liver, lung, testis and brain 1 h after administration. After 24 h the damage remained on an enhanced level in liver, lung and testis after styrene oxide administration and in all organs except liver after styrene administration.
