title: Proliferative activity in the colon of the mouse and its modulation by dietary starch, fat, and cellulose.
abstract: The effect of dietary starch, fat, and cellulose on colonic proliferation was studied in female C57Bl/6J mice after 4 weeks of feeding with diets containing various levels of starch (3, 36, and 57-65%), various levels of fat (corn oil, 5 and 29%) and various levels of cellulose (2 and 10%). Cell proliferation was measured by colchicine arrest and [3H]thymidine incorporation. The following parameters were analyzed: mitotic index, labeling index, and position of labelled cells along the crypt. Increasing starch content from 3 to 36% decreased cell proliferation both in low (5%) and high (29%) fat diets. By estimating simultaneously the effects of starch and fat with a single multiple regression model, we observed a decrease of mitotic index from 3.04 +/- 0.34 to 2.04 +/- 0.43 (means +/- SE) (P less than 0.05) when starch was increased from 3 to 36% regardless of the level of fat. Other proliferation parameters showed a similar pattern. Changes in dietary fat alone did not affect significantly cell proliferation. We also investigated the effect of starch at high levels (57-65%) and its interactions with cellulose. High starch (57-65%) increased the labeling index from 7.70 +/- 0.58 to 9.65 +/- 0.88 (P less than 0.05), when also considering the effect of cellulose in the multiple regression model. Cellulose by itself did not change the labeling index. Varying starch from 36 to 57-65% increased the number of cells/crypt column from 22.20 +/- 0.82 to 25.87 +/- 1.21 (P less than 0.05) and varying cellulose from 2 to 10% increased the number of cells/crypt column from 22.20 +/- 0.82 to 27.25 +/- 0.97 (P less than 0.01). The results indicate that either high or low fat diets, containing 36% starch, have the minimum proliferative effects in the mouse colon. However, diets containing high levels of both starch (57%) and cellulose (10%) may induce an increase in proliferation. These data suggest a potential beneficial effect of starch on colon proliferation.
authors.affiliation: Department of Pharmacology, University of Florence, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Caderni
authors.forename: F
authors.initials: F
authors.lastname: Bianchini
authors.forename: P
authors.initials: P
authors.lastname: Dolara
authors.forename: D
authors.initials: D
authors.lastname: Kriebel
mesh_terms: D000818:Animals; D002455:Cell Division; D002482:Cellulose / Q000494:pharmacology*; D003106:Colon / Q000166:cytology*; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004041:Dietary Fats / Q000494:pharmacology*; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D013213:Starch / Q000494:pharmacology*
chemical_list: D004040:Dietary Carbohydrates; D004041:Dietary Fats; D002482:Cellulose; D013213:Starch