title: Radiobiology and stathmokinetics of intestinal crypts associated with patches of Peyer.
abstract: The stathmokinetics and radiobiology of intestinal crypts directly adjoining the lymphoid patches of Peyer, have been compared with those of non-patch-associated crypts. Patch crypts contain an additional one to two rings of cells, the Mitotic Index for the whole crypt is higher than in non-patch crypts, and the apparent cell cycle time is insignificantly lower. Using single and split doses of gamma-rays, dose-survival curves were obtained for whole intestinal crypts, from which single-cell survival curves were derived for the clonogenic cells of the crypt. For a single-hit, multitarget, model, the extrapolation numbers of the cell survival curves for patch and non-patch crypts were the same (approximately 35) but the final D0 for cells of the patch crypts was significantly higher (2.1 versus 1.7 Gy). A linear-quadratic fit gave a similar ratio of alpha/beta (approximately 10) for the two curves. For a given level of crypt depletion, the number of clonogenic cells per crypt derived by the use of equal split doses of radiation, was the same for patch and non-patch crypts. This number is a function of the dose regime employed: the higher the level of crypt depletion, the higher the derived number of cells (range 10 to 45, for non-patch crypts).
mesh_terms: D000818:Animals; D002455:Cell Division / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D007422:Intestines / Q000166:cytology / Q000528:radiation effects*; D008297:Male; D051379:Mice; D008940:Mitotic Index; D010581:Peyer's Patches / Q000166:cytology*