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Cellular response of the rat brain to single doses of (137)Cs ? rays does not predict its response to prolonged 'biologically equivalent' fractionated doses.

ABSTRACT: To determine if the brain's response to single doses predicts its response to 'biologically equivalent' fractionated doses.Young adult male Fischer 344 rats were whole-brain irradiated with either single 11, 14, or 16.5 Gy doses of (137)Cs ? rays or their 'biologically equivalent' 20, 30, or 40 Gy fractionated doses (fWBI) delivered in 5 Gy fractions, twice/week for 2, 3, or 4 weeks, respectively. At 2 months post-irradiation, cellular markers of inflammation (total, activated, and newborn microglia) and neurogenesis (newborn neurons) were measured in 40 ?m sections of the dentate gyrus (DG).Although the total number of microglia in the DG/hilus was not significantly different (p > 0.7) in unirradiated, single dose, and fWBI rats, single doses produced a significant (p < 0.003) increase in the percent-activated microglia; fWBI did not (p > 0.1). Additionally, single doses produced a significant (p < 0.002) dose-dependent increase in surviving newborn microglia; fWBI did not (p < 0.8). Although total proliferation in the DG was reduced equally by single and fWBI doses, single doses produced a significant dose-dependent (p < 0.02) decrease in surviving newborn neurons; fWBI did not (p > 0.6).These data demonstrate that the rat brain's cellular response to single doses often does not predict its cellular response to 'biologically equivalent' fWBI doses.

SUBMITTER: Greene-Schloesser DM

PROVIDER: S-EPMC4326093 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature

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Cellular response of the rat brain to single doses of (137)Cs γ rays does not predict its response to prolonged 'biologically equivalent' fractionated doses.

Greene-Schloesser Dana M DM Kooshki Mitra M Payne Valerie V D'Agostino Ralph B RB Wheeler Kenneth T KT Metheny-Barlow Linda J LJ Robbins Mike E ME

International journal of radiation biology 20140901 9

<h4>Purpose</h4>To determine if the brain's response to single doses predicts its response to 'biologically equivalent' fractionated doses.<h4>Methods</h4>Young adult male Fischer 344 rats were whole-brain irradiated with either single 11, 14, or 16.5 Gy doses of (137)Cs γ rays or their 'biologically equivalent' 20, 30, or 40 Gy fractionated doses (fWBI) delivered in 5 Gy fractions, twice/week for 2, 3, or 4 weeks, respectively. At 2 months post-irradiation, cellular markers of inflammation (tot ...[more]

PMID: 24937374

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Cellular response of the rat brain to single doses of (137)Cs ? rays does not predict its response to prolonged 'biologically equivalent' fractionated doses.

Publications

Cellular response of the rat brain to single doses of (137)Cs γ rays does not predict its response to prolonged 'biologically equivalent' fractionated doses.

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