Intestinal cell proliferation is influenced by intakes of protein and energy, aflatoxin, and Whole‐body radiation

Abstract

Intestinal epithelial cell proliferation in young male F344 rats was measured in response to dietary protein content (5%, 10%, and 20% casein diets), energy restriction (energy intake was 60% of ad libitum energy intakes of animals consuming the 20% casein diet), total diet restriction (dietary intake was 60% of the ad libitum intake of 20% casein diet group), aflatoxin administration, and whole body irradiation. Cellular proliferation was measured in sections of jejunum, ileum, proximal colon, and distal colon with the [³H]thymidine technique. Restricting energy or total diet intakes by 40% from ad libitum levels reduced proliferation in epithelial cells throughout the intestine. In comparison to the 5% casein diet, the 20% casein diet resulted in modestly lower cellular proliferation in all intestinal segments. Radiation induced a decrease in cellular proliferation in the jejunum and ileum; this decrease was prevented by a 20% casein diet. Pretreatment with aflatoxin B₁ decreased intestinal cell proliferation throughout the intestine, and this decrease was not influenced by the protein content of the diet.