title: beta-Adrenoceptor stimulation up-regulates phosphodiesterase 4 activity and reduces prostaglandin E2-inhibitory effects in human neutrophils.
abstract: Human neutrophils were treated for 4 h with a combination of salbutamol (1 microM), a beta2-adrenoceptor agonist, and rolipram (30 microM), a selective phosphodiesterase 4 inhibitor, to investigate whether this treatment produces up-regulation of phosphodiesterase activity with functional consequences. Anion-exchange chromatography coupled with the use of selective activators and inhibitors demonstrated that a phosphodiesterase activity with characteristics of the isoenzyme type 4 was increased in drug-treated cells. Kinetic analysis showed a approximately 1.5-fold increase in Vmax without alteration of Km values. The augmented phosphodiesterase activity in drug-treated cells was abolished by actinomycin D. Cyclic AMP content in drug-treated cells was higher than resting values (27.28+/-2.79 pmol/10(6) cells vs. 0.34+/-0.03 pmol/10(6) cells). Reverse transcriptase-polymerase chain reaction showed increased expression of mRNA transcripts for PDE4B and PDE4A in drug-treated cells. Functionally, up-regulation of phosphodiesterase 4 reduced the inhibition by prostaglandin E2 of zymosan-induced superoxide generation.
authors.affiliation: Departament de Farmacologia, Facultat de Medicina i Odontologia, Universitat de València, Spain. jose.l.ortiz@uv.es
authors.forename: J L
authors.initials: JL
authors.lastname: Ortiz
authors.forename: F J
authors.initials: FJ
authors.lastname: Dasí
authors.forename: J
authors.initials: J
authors.lastname: Cortijo
authors.forename: E J
authors.initials: EJ
authors.lastname: Morcillo
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000322:Adrenergic Agonists / Q000494:pharmacology*; D000328:Adult; D000420:Albuterol / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; D015232:Dinoprostone / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D018375:Neutrophil Activation; D009504:Neutrophils / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020889:Rolipram / Q000494:pharmacology; D013481:Superoxides / Q000037:antagonists & inhibitors / Q000378:metabolism; D015854:Up-Regulation; D015054:Zymosan / Q000494:pharmacology
chemical_list: D000322:Adrenergic Agonists; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D018343:Receptors, Adrenergic, beta-2; D013481:Superoxides; D015054:Zymosan; D000242:Cyclic AMP; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D054703:Cyclic Nucleotide Phosphodiesterases, Type 4; C517355:PDE4A protein, human; C517360:PDE4B protein, human; D020889:Rolipram; D015232:Dinoprostone; D000420:Albuterol