title: Cyclic adenosine-3',5'-monophosphate alters hydrolysis of phospholipids by mouse embryo palate mesenchyme cells.
abstract: The purpose of this study was to determine whether inhibition of release of arachidonic acid from mouse embryo palate mesenchyme (MEPM) cells in response to cAMP is due to a selected or generalized inhibition of hydrolysis of esterified pools of arachidonic acid. The calcium ionophore A23187 proved to be a useful probe of phospholipid hydrolases in MEPM cells, since it stimulated release of radiolabeled fatty acids from phospholipids of prelabeled MEPM cells as a function of the length of exposure, concentration, and concentration of Ca2+ in the medium. Elevation of intracellular levels of cAMP by treatment with (-) isoproterenol resulted in the inhibition of release of radiolabeled arachidonic acid in response to A23187. Analysis by quantitative gas-liquid chromatography revealed the source of the arachidonic acid released in response to the ionophore to be 1,2-diradyl-sn-glycero-3-phosphoethanolamine; elevation of intracellular levels of cAMP inhibited hydrolysis of this substrate, but may have stimulated hydrolysis of 1,2-diradyl-sn-glycero-3-phosphocholine. These findings permit the conclusions that 1) the ionophore stimulates activities of selected phospholipases A in MEPM cells and 2) cAMP modulates certain phospholipases A in MEPM cells in a specific manner.
mesh_terms: D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D003994:Bucladesine / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology; D008563:Membrane Lipids / Q000378:metabolism; D008648:Mesoderm / Q000378:metabolism; D051379:Mice; D010159:Palate / Q000196:embryology* / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*
chemical_list: D001095:Arachidonic Acids; D005230:Fatty Acids, Nonesterified; D008563:Membrane Lipids; D010743:Phospholipids; D016718:Arachidonic Acid; D000001:Calcimycin; D003994:Bucladesine; D000242:Cyclic AMP; D007545:Isoproterenol