Cholecystokinin octapeptide CCK-8 and carbachol reduce [(32)P]orthophosphate labeling of phosphatidylcholine without modifying phospholipase D activity in rat pancreatic acini.
We have studied phospholipase D activation in [(32)P]orthophosphoric acid-prelabeled rat pancreatic acini by measuring the formation of (32)P-phosphatidylalcohols as stimulated in the presence of ethanol or butanol. A small but significant and time-dependent basal accumulation of [(32)P]phosphatidylethanol and [(32)P]phosphatidylbutanol was detected, which was further stimulated by phorbol myristate acetate, orthovanadate and pervanadate. However, the secretagogues cholecystokinin octapeptide and carbachol did not enhance basal accumulation of (32)P-phosphatidylalcohol, yet they decreased [(32)P]phosphatidylcholine content and stimulated the generation of [(32)P]phosphatidic acid. Our results stress the need to examine the transphosphatidylation reaction as well as agonist effects on the synthesis of phosphatidylcholine in order to assess unambiguously phospholipase D activity.
Sarri
E
E
Departament de Bioquimica i Biologia Molecular, Universitat Autònoma de Barcelona, Spain. Elisabet.Sarri@uab.es
Ramos
B
B
Salido
G
G
Claro
E
E
D000818:Animals; D000440:Butanols / Q000378:metabolism / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D000431:Ethanol / Q000378:metabolism / Q000494:pharmacology; D020404:Glycerophospholipids / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism / Q000494:pharmacology; D007700:Kinetics; D010179:Pancreas / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism*; D010712:Phosphatidic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism*; D010739:Phospholipase D / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012844:Sincalide / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014638:Vanadates / Q000494:pharmacology
D000440:Butanols; D020404:Glycerophospholipids; D010710:Phosphates; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; C076715:pervanadate; C068564:phosphatidylbutanol; C051521:phosphatidylethanol; D000431:Ethanol; D014638:Vanadates; D002217:Carbachol; D006861:Hydrogen Peroxide; D010739:Phospholipase D; D012844:Sincalide; D013755:Tetradecanoylphorbol Acetate