On the biochemical mechanism of tumorigenesis in mouse skin. VII. The effects of tumor promoters on 3H-choline and 3H-glycerol incorporation into mouse epidermal phosphatidylcholine in relation to their effects on 3H-thymidine incorporation into DNA.
The kinetics of the stimulation of phospholipid and DNA biosynthesis in mouse epidermis after treatment with various tumor promoting agents has been investigated. 3H-choline and 3H-glycerol were used as precursors for phosphatidylcholine. An early stimulation of 3H-choline incorporation into phosphatidylcholine is observed which always precedes the stimulation of 3H-thymidine incorporation into epidermal DNA. This is interpreted as being a manifestation of the proliferation of cellular membranes in preparation for cell division. Appreciable differences are observed in the incorporation of 3H-choline and 3H-glycerol into phosphatidylcholine, the possible reasons for which are discussed. It is concluded that 3H-choline incorporation is a more reliable parameter for the measurement of phosphatidylcholine biosynthesis than 3H-glycerol incorporation. The relationship between those effects on phospholipid synthesis and the tumor promoting activity of the substances tested is discussed.
D000818:Animals; D002794:Choline / Q000378:metabolism; D004273:DNA, Neoplasm / Q000096:biosynthesis*; D005260:Female; D005990:Glycerol / Q000378:metabolism; D051379:Mice; D009374:Neoplasms, Experimental; D010703:Phorbol Esters / Q000494:pharmacology*; D010704:Phorbols / Q000494:pharmacology*; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D012867:Skin / Q000378:metabolism; D012878:Skin Neoplasms / Q000139:chemically induced / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors
D004273:DNA, Neoplasm; D010703:Phorbol Esters; D010704:Phorbols; D010713:Phosphatidylcholines; D002794:Choline; D013755:Tetradecanoylphorbol Acetate; D005990:Glycerol