Neutron RBEs and the radiosensitive target for mouse immature oocyte killing

Journal Article · Wed Jul 01 04:00:00 EDT 1987 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3577020· OSTI ID:6071066

Straume, T; Dobson, R L; Kwan, T C

The highly radiosensitive immature oocytes of mice were irradiated in vivo with graded doses of /sup 252/Cf fission radiation, 0.43- or 15-MeV neutrons, or /sup 60/Co gamma rays. Comparisons of oocyte survival for neutrons and for gamma rays demonstrate that neutron RBEs for the killing of these important cells do not reach the high values (30-50 or more) at low doses observed for several other biological end points. Rather, neutrons differ little in effectiveness from gamma rays in killing these extremely sensitive murine oocytes. For 0.43-MeV neutrons, RBEs obtained from fitted survival curves reach only 1.7 at 0.1 rad. For 15-MeV neutrons, they are not significantly different from 1 at any dose tested (lowest, 4.5 rad). For /sup 252/Cf fission neutrons (E = 2.15 MeV), RBEs are intermediate between those for 0.43- and 15-MeV neutrons. For all neutron energies tested, the RBEs are particularly low in the juvenile period, a time when murine immature oocytes are especially radiosensitive. With exposure just prior to birth, however, when these cells are much less easily killed, higher, more usual RBEs are found. The minimum size of the lethality target in mouse immature oocytes, estimated from the inactivation constant for 0.43-MeV neutrons and microdosimetric values, is larger than the nucleus but not larger than the cell. This and related analytical considerations suggest that the hypersensitive target in these particular oocytes is the plasma membrane, a finding which is in excellent accord with results from other experiments using different, contrasting radiations and dose deliveries (accelerated Si14+ ions, gamma rays, and beta rays from /sup 3/HOH compared with those from (/sup 3/H)thymidine).

• Research Organization: Lawrence Livermore National Lab., CA
• OSTI ID: 6071066
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 111:1; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560120* -- Radiation Effects on Biochemicals
Cells
& Tissue Culture
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ALPHA DECAY RADIOISOTOPES
ANIMALS
AZINES
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CALIFORNIUM 252
CALIFORNIUM ISOTOPES
CELL CONSTITUENTS
CELL KILLING
CELL MEMBRANES
COBALT 60
COBALT ISOTOPES
DATA
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY RANGE
EVEN-EVEN NUCLEI
EXPERIMENTAL DATA
FAST NEUTRONS
FERMIONS
FISSION NEUTRONS
GAMMA RADIATION
GERM CELLS
HADRONS
HEAVY NUCLEI
HEAVY WATER
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INFORMATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MEMBRANES
MEV RANGE
MICE
MINUTES LIVING RADIOISOTOPES
NEUTRONS
NUCLEI
NUCLEONS
NUCLEOSIDES
NUCLEOTIDES
NUMERICAL DATA
ODD-ODD NUCLEI
OOCYTES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PYRIMIDINES
RADIATIONS
RADIOISOTOPES
RADIOSENSITIVITY
RBE
RIBOSIDES
RODENTS
SURVIVAL CURVES
THYMIDINE
TRITIUM COMPOUNDS
VERTEBRATES
WATER
YEARS LIVING RADIOISOTOPES