title: Effect of vitamin A deficiency on intestinal cell proliferation in the rat.
abstract: Cell division kinetics and the biochemical composition of the small intestine of normal and mildly vitamin A-deficient rats have been examined. Thymidine labeling index, growth fraction and the content of DNA, RNA and protein in the jejunal mucosa were not significantly affected by vitamin A deficiency. On the other hand, the duration of the cell cycle of jejunal crypt cells was found to be lengthened by vitamin A deficiency and this increase in generation time was due mainly to a lengthening of the DNA synthesis phase. Furthermore, the labeling pattern of the newly divided crypt cells of the vitamin A-deficient rats was strikingly different from that of the vitamin A-supplemented rats, suggesting an impaired migration of cells out of the crypts. These findings suggest that vitamin A may play a role in the regulation of cell division in the small intestine of the rat.
mesh_terms: D000818:Animals; D002455:Cell Division; D004247:DNA / Q000378:metabolism; D007413:Intestinal Mucosa / Q000502:physiology; D007583:Jejunum / Q000254:growth & development / Q000502:physiology*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D012313:RNA / Q000378:metabolism; D051381:Rats; D013936:Thymidine / Q000378:metabolism; D014801:Vitamin A / Q000502:physiology; D014802:Vitamin A Deficiency / Q000503:physiopathology*
chemical_list: D014801:Vitamin A; D012313:RNA; D004247:DNA; D013936:Thymidine