Biomaterial Database

Quantitative and qualitative effect of gamma-ray dose-rate on mutagenesis in human lymphoblastoid cells. 1996

I Furuno-Fukushi, and K Tatsumi, and M Takahagi, and A Tachibana

Division of Biology, National Institute of Radiological Sciences, Chiba, Japan.

Induction of mutations to 6-thioguanine resistance (TGr) by gamma-rays at three different dose-rates and molecular changes in the HPRT gene were studied in human lymphoblastoid WIL2-NS cells. Mutant induction showed a curvilinear dose-response for acute irradiation (30 Gy/h). The total mutant frequency was lower after irradiation at 0.17 or 0.006 Gy/h compared with acute irradiation. An apparent linear relationship between total dose and mutant frequency was found for the chronic irradiations. Spontaneous mutant frequency increased linearly with the exposure time of protracted irradiation at 0.006 Gy/h. After the spontaneous mutant frequency was subtracted from the total mutant frequency for irradiation at 0.006 Gy/h, no significant difference was found in the mutant frequency as a function of dose between the cultures irradiated at 0.17 Gy/h and those at 0.006 Gy/h. The inverse dose-rate effect, which has been observed in proliferating mouse L5178Y leukemia cells was not evident in WIL2-NS cells at the dose-rates employed. Structural alterations at the HPRT locus in TGr mutants were examined with the multiplex PCR method and compared among cultures irradiated at different dose-rates. Assuming that the mutants isolated were primarily independent, approximately 17% of spontaneous mutants were deletion mutants. When the fraction of spontaneous mutants in the irradiated cultures was subtracted from the total fraction of each type of mutant, it is clear that low dose-rate gamma-rays induced deletion mutations at the HPRT locus just as efficiently (79%) as high dose-rate gamma-rays (74%).

UI	MeSH Term	Description	Entries
D007041	Hypoxanthine Phosphoribosyltransferase	An enzyme that catalyzes the conversion of 5-phosphoribosyl-1-pyrophosphate and hypoxanthine, guanine, or MERCAPTOPURINE to the corresponding 5'-mononucleotides and pyrophosphate. The enzyme is important in purine biosynthesis as well as central nervous system functions. Complete lack of enzyme activity is associated with the LESCH-NYHAN SYNDROME, while partial deficiency results in overproduction of uric acid. EC 2.4.2.8.	Guanine Phosphoribosyltransferase,HPRT,Hypoxanthine-Guanine Phosphoribosyltransferase,IMP Pyrophosphorylase,HGPRT,HPRTase,Hypoxanthine Guanine Phosphoribosyltransferase,Phosphoribosyltransferase, Guanine,Phosphoribosyltransferase, Hypoxanthine,Phosphoribosyltransferase, Hypoxanthine-Guanine,Pyrophosphorylase, IMP
D008969	Molecular Sequence Data	Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.	Sequence Data, Molecular,Molecular Sequencing Data,Data, Molecular Sequence,Data, Molecular Sequencing,Sequencing Data, Molecular
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D002470	Cell Survival	The span of viability of a cell characterized by the capacity to perform certain functions such as metabolism, growth, reproduction, some form of responsiveness, and adaptability.	Cell Viability,Cell Viabilities,Survival, Cell,Viabilities, Cell,Viability, Cell
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D004307	Dose-Response Relationship, Radiation	The relationship between the dose of administered radiation and the response of the organism or tissue to the radiation.	Dose Response Relationship, Radiation,Dose-Response Relationships, Radiation,Radiation Dose-Response Relationship,Radiation Dose-Response Relationships,Relationship, Radiation Dose-Response,Relationships, Radiation Dose-Response
D005720	Gamma Rays	Penetrating, high-energy electromagnetic radiation emitted from atomic nuclei during NUCLEAR DECAY. The range of wavelengths of emitted radiation is between 0.1 - 100 pm which overlaps the shorter, more energetic hard X-RAYS wavelengths. The distinction between gamma rays and X-rays is based on their radiation source.	Gamma Wave,Gamma Radiation,Nuclear X-Rays,Radiation, Gamma,X-Rays, Nuclear,Gamma Radiations,Gamma Ray,Gamma Waves,Nuclear X Rays,Nuclear X-Ray,Ray, Gamma,Wave, Gamma,Waves, Gamma,X Rays, Nuclear,X-Ray, Nuclear
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001483	Base Sequence	The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.	DNA Sequence,Nucleotide Sequence,RNA Sequence,DNA Sequences,Base Sequences,Nucleotide Sequences,RNA Sequences,Sequence, Base,Sequence, DNA,Sequence, Nucleotide,Sequence, RNA,Sequences, Base,Sequences, DNA,Sequences, Nucleotide,Sequences, RNA