DNA single-strand breaks, double-strand breaks, and crosslinks in rat testicular germ cells: Measurements of their formation and repair by alkaline and neutral filter elution

Journal Article · Sat Jun 01 00:00:00 EDT 1985 · Cell Biology and Toxicology; (USA)

DOI:https://doi.org/10.1007/BF00120163· OSTI ID:6983397

Bradley, M O; Dysart, G ^[1]

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1. Merck Institute for Therapeutic Research, West Point, PA (USA)

This work describes a neutral and alkaline elution method for measuring DNA single-strand breaks (SSBs), DNA double-strand breaks (DSBs), and DNA-DNA crosslinks in rat testicular germ cells after treatments in vivo or in vitro with both chemical mutagens and gamma-irradiation. The methods depend upon the isolation of testicular germ cells by collagenase and trypsin digestion, followed by filtration and centrifugation. {sup 137}Cs irradiation induced both DNA SSBs and DSBs in germ cells held on ice in vitro. Irradiation of the whole animal indicated that both types of DNA breaks are induced in vivo and can be repaired. A number of germ cell mutagens induced either DNA SSBs, DSBs, or cross-links after in vivo and in vitro dosing. These chemicals included methyl methanesulfonate, ethyl methanesulfonate, ethyl nitrosourea, dibromochlorpropane, ethylene dibromide, triethylene melamine, and mitomycin C. These results suggest that the blood-testes barrier is relatively ineffective for these mutagens, which may explain in part their in vivo mutagenic potency. This assay should be a useful screen for detecting chemical attack upon male germ-cell DNA and thus, it should help in the assessment of the mutagenic risk of chemicals. In addition, this approach can be used to study the processes of SSB, DSB, and crosslink repair in DNA of male germ cells, either from all stages or specific stages of development.

• OSTI ID: 6983397
• Journal Information: Cell Biology and Toxicology; (USA), Vol. 1:3; ISSN 0742-2091
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
SPERMATOZOA
DNA REPAIR
STRAND BREAKS
MEASURING METHODS
BIOLOGICAL EFFECTS
CESIUM 137
CROSS-LINKING
DNA
EMS
FILTRATION
GAMMA RADIATION
GENETIC RADIATION EFFECTS
IN VITRO
IN VIVO
METHYL METHANESULFONATE
MITOMYCIN
MUTAGENS
NITROSOUREAS
RADIOINDUCTION
RATS
SULFONATES
ULTRACENTRIFUGATION
ALKALI METAL ISOTOPES
ANIMALS
ANTI-INFECTIVE AGENTS
ANTIBIOTICS
ANTIMITOTIC DRUGS
ANTINEOPLASTIC DRUGS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CENTRIFUGATION
CESIUM ISOTOPES
CHEMICAL REACTIONS
DRUGS
ELECTROMAGNETIC RADIATION
ESTERS
GAMETES
GENETIC EFFECTS
GERM CELLS
IONIZING RADIATIONS
ISOTOPES
MAMMALS
NITROSO COMPOUNDS
NUCLEI
NUCLEIC ACIDS
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
POLYMERIZATION
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RECOVERY
REPAIR
RODENTS
SEPARATION PROCESSES
SULFONIC ACID ESTERS
VERTEBRATES
YEARS LIVING RADIOISOTOPES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture
560152 - Radiation Effects on Animals- Animals
560300 - Chemicals Metabolism & Toxicology