Inhibition of phosphatidylcholine synthesis by vasopressin and angiotensin in rat hepatocytes.
The addition of 1 microM-vasopressin or -angiotensin to isolated rat hepatocytes induced a fast transient inhibition of the rate of incorporation of [Me-3H]choline into phosphatidylcholine. The cationophore A23187 induced a similar inhibition of phosphatidylcholine synthesis. The addition of micromolar Ca2+ to rat liver microsomes inhibited the activity of CDP-choline: 1,2-diacylglycerol cholinephosphotransferase. This inhibition is due a decrease in the Vmax. of the enzyme without affecting the Km for CDP-choline. It is concluded that Ca2+ regulates phosphatidylcholine synthesis in rat liver.
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002794:Choline / Q000378:metabolism; D003864:Depression, Chemical; D066298:In Vitro Techniques; D007700:Kinetics; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D014667:Vasopressins / Q000494:pharmacology*
D010713:Phosphatidylcholines; D014667:Vasopressins; D000804:Angiotensin II; D000001:Calcimycin; D002794:Choline; D002118:Calcium