Modifications of S-phase cell distribution in the intestinal crypts after multiple daily fractionation

• Published in: Acta radiologica. Oncology Vol. 22; no. 6; p. 441
• Main Authors: Becciolini, A, Cremonini, D, Fabbrica, D, Balzi, M
• Format: Journal Article
• Language: English
• Published: Sweden 1983
• Subjects: Animals; beta-Fructofuranosidase; Cell Count; Cell Division - radiation effects; Cobalt Radioisotopes - therapeutic use; Dose-Response Relationship, Radiation; Epithelium - radiation effects; Female; Glycoside Hydrolases - analysis; Interphase - radiation effects; Intestinal Mucosa - cytology; Intestinal Mucosa - enzymology; Intestinal Mucosa - radiation effects; Microscopy, Electron, Scanning; Radioisotope Teletherapy - methods; Rats; Rats, Inbred Strains; Thymidine - metabolism; Time Factors
• ISSN: 0349-652X
• DOI: 10.3109/02841868309135968

The effects obtained by multiple daily fractionation (3 Gy X 2 or 3 Gy X 2 X 2) on the distribution of S-phase cells along the crypt of the small intestine were investigated. The frequency of labelled cell distribution was reduced at early intervals; then the proliferating compartment gradually extended to the villus junctions. During recovery labelled cell frequency in the lower half of the crypts returned to control levels, while labelled cells were present in the differentiating area. With lower total dose modifications were milder and, as early as 72 h before exposure, distribution was already similar to controls. Invertase activity showed an initial increase and a higher reduction during acute damage when fractionation with higher doses was used. A lack of return to normal activity was present even 11 days after exposure when, however, the characteristic circadian pattern was observed.