title: Cytogenetic effects of fractionated or unfractionated X-ray exposures to mouse spermatogonia.
abstract: The induction of chromosomal aberrations in mouse spermatogonia was studied, after single (50 and 100 rad) and fractionated doses (50 / 50 rad spaced 24 h apart), a short time after irradiation, by analysis of mitotic stages. From 17 to 21 h after the second fraction of the dose, the recorded frequencies of chromosomal deletions and exchanges were fully additive when compared with single "control" doses. Thus there was no suggestion of any sensitization effect of the first exposure. Possible reasons for this are discussed.
mesh_terms: D000818:Animals; D002842:Chromatids / Q000528:radiation effects; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D008297:Male; D051379:Mice; D013093:Spermatogonia / Q000528:radiation effects*; D013094:Spermatozoa / Q000528:radiation effects*; D013997:Time Factors