Histologic effects of high energy electron and proton irradiation of rat brain detected with a silver-degeneration stain.
Application of the degeneration sensitive, cupric-silver staining method to brain sections of male Sprague-Dawley rats irradiated 4 days before sacrifice with 155 Mev protons, 2-8 Gy at 1 Gy/min (N=6) or 22-l0lGy at 20 Gy/min (N=16) or with 18.6 Mev electrons, 32-67 Gy at 20 Gy/min (N=20), doses which elicit behavioral changes (accelerod or conditioned taste aversion), resulted in a display of degeneration of astrocyte-like cell profiles which were not uniformly distributed.  Plots of 'degeneration scores' (counts of profiles in 29 areas) vs. dose for the proton and electron irradiations displayed a linear dose response for protons in the range of 2-8 Gy.  In the 20-100 Gy range, for both electrons and protons the points were distributed in a broad band suggesting a saturation curve.  The dose range in which these astrocyte-like profiles becomes maximal corresponds well with the dose range for the X-ray eradication of a subtype of astrocytes, 'beta astrocytes'.
Switzer RC 3rd
Department of Pathology, University of Tennessee Medical Center, Knoxville 37920, USA.
Bogo
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Mickley
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GA
D000818:Animals; D001253:Astrocytes / Q000473:pathology / Q000528:radiation effects*; D001522:Behavior, Animal / Q000528:radiation effects; D001921:Brain / Q000473:pathology* / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004583:Electrons; D008297:Male; D011522:Protons; D011829:Radiation Dosage; D011839:Radiation, Ionizing; D051381:Rats; D017207:Rats, Sprague-Dawley; D016622:Silver Staining / Q000379:methods
D011522:Protons