Accession Number : AD0648137

Title :   MECHANISM OF ACTION OF AET. THE PROTECTION OF DNA AGAINST IONIZING RADIATION BY GED.

Descriptive Note : Rept. for 1 Sep 65-31 Aug 66,

Corporate Author : ALBERT EINSTEIN MEDICAL CENTER PHILADELPHIA PA RADIATION RESEARCH LAB

Personal Author(s) : Kollmann,George ; Shapiro,Bernard ; Martin,David

Report Date : JAN 1967

Pagination or Media Count : 13

Abstract : The specific viscosity was measured in unirradiated and irradiated solutions of highly polymerized, salmon sperm DNA alone and containing bis(2-guanidoethyl) disulfide (GED), oxidized glutathione (GSSG), cystamine, cadaverine, agmatine, and pentamethylene diguanidine (PMDG). Radiation-induced decrease in viscosity was almost completely prevented by .001 M GED up to 100 kR at which dose unprotected DNA solution viscosity approximated that of the solvent. When viscosity was measured at 90 degrees, to study the effect on single strands, radiation effect and GED protection of DNA were demonstrated with doses as low as 100 to 200 R. GED had to be present during irradiation for protection but could be removed by dialysis after irradiation without loss of protection. Equilibrium dialysis demonstrated binding of GED to DNA. Other disulfides, GSSG, and cystamine showed less binding to DNA and also showed less protection. The diamine cadaverine and the PMDG were bound to DNA as well as cystamine and GED, respectively, but showed no protection. The mechanism of action of GED appears to be a localized radical scavenging at the surface of the DNA molecule. (Author)

Descriptors :   (*RADIOPROTECTIVE AGENTS, *DEOXYRIBONUCLEIC ACIDS), RADIOBIOLOGY, ORGANIC SULFUR COMPOUNDS, GUANIDINES, RADIATION EFFECTS, ENZYMES, VISCOSITY, RADIATION DOSAGE

Subject Categories : Radiobiology
      Pharmacology

Distribution Statement : APPROVED FOR PUBLIC RELEASE