title: Acidic phospholipids and lysophospholipids stimulate cAMP phosphodiesterase of rat liver microsomal membranes.
abstract: Acidic phospholipids and lysophospholipids modify cAMP phosphodiesterase activity of rat liver microsomal membranes to different extents, depending on the cAMP concentrations employed. At low concentrations, they activate the hormone-sensitive low-Km form of the enzyme through an increase of Vmax (diphosphatidylglycerol greater than phosphatidylglycerol greater than phosphatidic acid = lysophosphatidylserine greater than phosphatidylserine greater than lysophosphatidylcholine). At high concentrations, only lysophospholipids activate the high-Km form of phosphodiesterase through a marked increase in both Vmax and apparent Km for the cAMP.
authors.affiliation: Department of Pharmacology, University of Padova, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Carpenedo
authors.forename: M
authors.initials: M
authors.lastname: Floreani
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D003902:Detergents; D006863:Hydrogen-Ion Concentration; D007425:Intracellular Membranes / Q000201:enzymology*; D007700:Kinetics; D008246:Lysophospholipids / Q000378:metabolism*; D008862:Microsomes, Liver / Q000201:enzymology* / Q000648:ultrastructure; D010743:Phospholipids / Q000378:metabolism*; D051381:Rats
chemical_list: D003902:Detergents; D008246:Lysophospholipids; D010743:Phospholipids; D015105:3',5'-Cyclic-AMP Phosphodiesterases