Circadian variations of epithelial cell proliferation in human rectal crypts
| Autor: | Antonio Percesepe, Fabio Maria Vecchio, Claudio Coco, Giancarlo Marra, Rita Ficarelli, Enzo D'Arcangelo, Alessandro Rinelli, Franco Armelao, Marcello Anti |
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| Přispěvatelé: | University of Zurich, Marra, Giancarlo |
| Rok vydání: | 1994 |
| Předmět: |
Adult
Male medicine.medical_specialty Time Factors Cell division Crypt Rectum colorectal cancer Biology Internal medicine medicine Humans 2715 Gastroenterology Circadian rhythm Intestinal Mucosa epithelial cell proliferation Analysis of Variance Hepatology Cell growth Compartment (ship) 10061 Institute of Molecular Cancer Research Gastroenterology Middle Aged Epithelium Circadian Rhythm medicine.anatomical_structure Endocrinology 570 Life sciences biology Autoradiography 2721 Hepatology Female Animal studies Cell Division Thymidine |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 0016-5085 |
| Popis: | Background/Aims: Evidence (almost exclusively from animal studies) suggests that proliferation within the colorectal mucosa undergoes circadian variations. The epithelial cells that line the human colorectal crypt occupy definite positions along the longitudinal axis according to their proliferative potential and degree of differentiation. Thus, circadian rhymicity was investigated in humans to locate the areas along the longitudinal crypt axis in which diurnal fluctuation might occur. Methods: Rectal mucosal biopsy specimens were obtained every 4 hours for a 24-hour span from each of 23 subjects (8 healthy volunteers and 15 with histories of sporadic adenomatous polyps). [ 3 H]thymidine histoautoradiography was used to determine ratios of S-phase to total cells (total labeling index) in the crypt. Glands were also divided into 5 equal compartments from base (compartment 1) to mouth (compartment 5), and labeling indices were calculated for each. Results: Important temporal variations were confined to compartment 2 (F = 5.15, P = 0.0003) and total labeling indices (F = 3.57, P = 0.005). Despite individual variations, proliferation was generally higher at night and lower during afternoon. Upper-crypt proliferative rates (compartments 4 and 5) remained decidedly stable (F = 0.5, P = NS ). Normal subjects and patients with polyps displayed similar circadian behaviors. Conclusions: Circadian fluctuation in proliferation is confined to the area of the crypt normally associated with replication. Upper-crypt indices, including those that were higher than normal (a colon-cancer risk marker) are stable over 24 hours. These findings should be useful in planning chemoprevention trials and chemotherapeutic regimens. |
| Databáze: | OpenAIRE |
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