Reparable and irreparable damage in yeast cells after low LET-irradiation
Creators
- 1. Gesellschaft fuer Strahlen- und Umweltforschung m.b.H., Frankfurt am Main (F.R. Germany). Abt. fuer Biophysikalische Strahlenforschung
Description
Diploid yeast cells in the early G1-phase were irradiated with 60Co-gamma-rays or 30 MeV electrons (anti L = 0.2 keV/μm) and with X-rays (effective photon energy = 40 keV; anti L = 3 keV/μm). The dose rates of the irradiations were so low (D = 27 rad/min) that maximum repair occurred during irradiation. 60Co-gamma-rays yield no irreparable damage up to absorbed doses D of about 120 krads. X-rays on the other hand, cause irreparable damage in the same dose range, yielding a survival fraction of 0.25 at D = 120 krads. Comparing the cumulative fractional absorbed dose distributions in L100 for 60Co-gamma-rays and for X-rays (Esub(eff) = 40 keV), the irreparable damages due to X-irradiation cannot be caused by the high LET fraction of the absorbed dose (L >= 10 keV/μm). In fact, the X-ray-induced irreparable damage is caused by the fraction of the absorbed dose in the LET range from about 1 keV/μm up to 10 keV/μm. (orig.)
Availability note (English)
MF available from INIS under the Report Number.Abstract (German)
Diploide Gerstezellen in der fruehen G1-Phase wurden mit 60Co-Gammastrahlen oder Elektronen von 30 MeV (anti L = 0,2 keV/μm) und mit Roentgenstrahlen (effektive Photonenenergie = 40 keV; anti L = 3 keV/μm) bestrahlt. Die Dosisleistungen lagen bei der Bestrahlung so niedrig (D = 27 rad/min), dass waehrend der Bestrahlung eine maximale Reparatur stattfand. 60Co-Gammastrahlen verursachen bis zu einer absorbierten Dosis D von etwa 120 krad keine irreparablen Schaeden, waehrend Roentgenstrahlen im gleichen Dosisbereich irreparable Schaeden verursachen (Ueberlebensrate von 0,25% bei D = 120 krad). Vergleicht man die prozentualen kumulativen absorbierten Dosisverteilungen in L100 bei 60Co-Gammastrahlen und Roentgenstrahlen (Esub(eff) = 40 keV), so zeigt sich, dass die irreparablen Schaeden bei dem hohen LET-Anteil der absorbierten Dosis zurueckgefuehrt werden koennen. Tatsaechlich werden die durch Roentgenstrahlen induzierten irreparabeln Schaeden durch die absorbierte Dosis im LET-Bereich von etwa 1 keV/μm bis zu 10 keV/μm verursacht. (orig./AK)
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Additional details
Publishing Information
- Imprint Pagination
- 5 p.
- Report number
- AED-Conf--75-549-003
Conference
- Title
- Conference on radiation and cellular control processes.
- Dates
- 6 Oct 1975.
- Place
- Giessen, F.R. Germany.
INIS
- Country of Publication
- Germany
- Country of Input or Organization
- Germany
- INIS RN
- 7244296
- Subject category
- S63: RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS;
- Resource subtype / Literary indicator
- Conference
- Descriptors DEI
- BIOLOGICAL REPAIR; CELL CYCLE; COBALT 60; DOSE-RESPONSE RELATIONSHIPS; LET; LOW DOSE IRRADIATION; RADIATION DOSE UNITS; RADIATION INJURIES; RADIOBIOLOGY; SURVIVAL CURVES; SURVIVAL TIME; X RADIATION; YEASTS
- Descriptors DEC
- BETA DECAY RADIOISOTOPES; BETA-MINUS DECAY RADIOISOTOPES; BIOLOGICAL EFFECTS; BIOLOGICAL RADIATION EFFECTS; BIOLOGICAL RECOVERY; BIOLOGY; COBALT ISOTOPES; DISEASES; ELECTROMAGNETIC RADIATION; ENERGY TRANSFER; FUNGI; INJURIES; INTERMEDIATE MASS NUCLEI; INTERNAL CONVERSION RADIOISOTO; IONIZING RADIATIONS; IRRADIATION; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; MICROORGANISMS; MINUTES LIVING RADIOISOTOPES; NUCLEI; ODD-ODD NUCLEI; PLANTS; RADIATION EFFECTS; RADIATIONS; RADIOISOTOPES; UNITS; YEARS LIVING RADIOISOTOPES
Optional Information
- Notes
- 2 figs.; 1 tab.; 1 ref. With abstract.