Oligodendroglial response to ionizing radiation: Dose and dose-rate response
An in vitro system using neuroglia from neonatal rat brain was developed to examining the morphologic, immunocytochemical and biochemical response of oligodendroglia to ionizing radiation. Following acute [gamma]-radiation at day-in-culture (DIC) 8, oligodendrocyte counts at DIC 14 were 55% to 65% of control values after 2 Gy, and 29% to 36% after 5 Gy. Counts increased to near-normal levels at DIC 21 in the 2 Gy group and to 75% of normal in the 5 Gy group. Myelin basic protein levels (MBP) at DIC 14 were 60% of control values after 2 Gy, and 40% after 5 Gy. At DIC 21, MBP after 2 Gy was 45% greater than that observed at DIC 14, but MBP, as a fraction of age-matched control values, dropped from 60% to 50%. Following 5 Gy, absolute MBP changed little between DIC 14 and DIC 21, but decreased from 40% to 25% of control cultures. It was concluded that oligodendrocytes in irradiated cultures had significantly lower functional capacity than did unirradiated controls. The response to split-dose irradiation indicated that nearly all sublethal damage in the oligodendrocyte population (and its precursors) was repaired within 3 h to 4 h. At DIC 14, the group irradiated in a single fraction had significantly lower oligodendrocyte counts than any group given split doses; all irradiated cultures had marked depression of MBP synthesis, but to significant differences referable to time interval between doses. At DIC 21, cultures irradiated at intervals of 0 h to 2 h had similar oligodendrocyte counts to one another, but these counts were significantly lower than in cultures irradiated at intervals of 4 h to 6 h; MBP levels remained depressed at DIC 21 for all irradiated cultures. The oligodendrocyte response to dose rate (0.03 to 1.97 Gy/min) was evaluated at DIC 14 and DIC 21. Exposure at 0.03 Gy/min suppressed oligodendrocyte counts at DIC 21 less than did higher dose rates in 5-Gy irradiated cultures.
- Research Organization:
- California Univ., Berkeley, CA (United States)
- OSTI ID:
- 5506596
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Oligodendroglial response to ionizing radiation: Dose and dose-rate response
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59 BASIC BIOLOGICAL SCIENCES
BRAIN
NERVE CELLS
GAMMA RADIATION
ACUTE EXPOSURE
DOSE-RESPONSE RELATIONSHIPS
BIOLOGICAL RADIATION EFFECTS
RESPONSE FUNCTIONS
DOSE RATES
IN VITRO
MYELIN
NEONATES
RATS
ANIMAL CELLS
ANIMALS
BIOLOGICAL EFFECTS
BODY
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
ELECTROMAGNETIC RADIATION
FUNCTIONS
IONIZING RADIATIONS
MAMMALS
MEMBRANES
NERVOUS SYSTEM
ORGANS
RADIATION EFFECTS
RADIATIONS
RODENTS
SOMATIC CELLS
VERTEBRATES
560120* - Radiation Effects on Biochemicals
Cells
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550200 - Biochemistry