On the physiological basis of vitamin A-stimulated growth.
The influence of vitamin A depletion on tissue composition was studied in rats that were marginally vitamin A deficient, i.e. at their weight plateau stage. The total number of cells (DNA) was decreased in most organs as a result of vitamin A depletion. In thymus, spleen and the sublingual glands there was also a dramatic reduction in the number of cells per gram of tissue and in thymus and sublingual glands there was an increase in the protein to DNA ratio as a result of absence of dietary.vitamin A. We present the hypothesis that vitamin A stimulates growth by a direct role in cell replication in addition to or instead of stimulating the differentiation of epithelial and bone cells.
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D006128:Growth / Q000187:drug effects*; D008099:Liver / Q000378:metabolism; D008297:Male; D009696:Nucleic Acids / Q000378:metabolism; D051381:Rats; D013154:Spleen / Q000378:metabolism; D013361:Sublingual Gland / Q000378:metabolism; D013363:Submandibular Gland / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism; D014801:Vitamin A / Q000502:physiology*; D014802:Vitamin A Deficiency / Q000503:physiopathology*
D009696:Nucleic Acids; D014801:Vitamin A