title: Effect of diethylstilboestrol on phosphatidylcholine biosynthesis and choline metabolism in the liver of roosters.
abstract: It has been known for 40 years that oestrogens stimulate phospholipid metabolism in roosters. We have investigated in vivo the mechanism for this effect. Young roosters were injected daily with 1 mg of diethylstilboestrol for 1--3 days. At 4 h after the last injection, 30 microCi of [Me-3H]choline was injected into the portal vein. At periods up to 3 min the livers were freeze-clamped and choline and its metabolites were extracted and resolved by t.l.c. Hormone treatment in the first 2 days resulted in a 2-fold increase in phosphorylation of [Me-3H]choline and a decrease in the oxidation of [Me-3H]choline to [3H]betaine. The concentrations of phosphocholine in liver were increased 2-fold during the first 2 days concomitant with a 2-fold increase in the rate of phosphatidylcholine biosynthesis. After 3 days of hormone treatment, many of the above effects were reversed and the rate of phosphatidylcholine biosynthesis decreased to approx. 60% of the control value. The results suggest that the initial hormone treatments activate choline kinase within 4 h and, thereby, divert choline form oxidation to betaine. The resulting increased phosphocholine concentrations cause an increase in the activity of CTP:phosphocholine cytidylyltransferase, which results in a doubling of the rate of phosphatidylcholine biosynthesis. After 3 days of hormone treatment, the biosynthesis of phosphatidylcholine is decreased, most likely by an effect on the cytidylyltransferase reaction.
mesh_terms: D000818:Animals; D002645:Chickens; D002794:Choline / Q000378:metabolism*; D003570:Cytidine Triphosphate / Q000378:metabolism; D004054:Diethylstilbestrol / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D013997:Time Factors
chemical_list: D010713:Phosphatidylcholines; D003570:Cytidine Triphosphate; D004054:Diethylstilbestrol; D002794:Choline