title: Effect of glucocorticoid on prostaglandin E1 mediated cyclic AMP formation by vascular smooth muscle cells.
abstract: The effect of glucocorticoid on the prostaglandin E1 (PGE1)-mediated cyclic AMP (cAMP) formation by vascular smooth muscle cells (VSMC) from renal arteries (RA) was studied in rats. Dexamethasone (DEX) at concentrations ranging from 10(-10) to approximately 10(-8) mol/l dose-dependently potentiates the PGE1-mediated response. This facilitation began at 6 h and reached its maximum after 24 h of DEX administration. Aldosterone (10(-6) mol/l) did not affect the dose-response curve of PGE1. Inhibitors of protein and RNA synthesis blocked this glucocorticoid effect. The basal activity of adenylate cyclase in DEX-treated cells was twice as high as in control cells. Treatment of VSMC with DEX increased cholera toxin- and pertussis toxin-stimulated adenylate cyclase activity. DEX treatment also augments forskolin-stimulated adenylate cyclase activity. These results suggest that DEX increases PGE1-mediated cAMP formation of VSMC from RA through a mechanism that involves the induction of protein synthesis, and that the activation of the catalytic unit may play some role in this facilitating process.
authors.affiliation: First Department of Internal Medicine, Osaka City University Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yasunari
authors.forename: M
authors.initials: M
authors.lastname: Kohno
authors.forename: K
authors.initials: K
authors.lastname: Murakawa
authors.forename: K
authors.initials: K
authors.lastname: Yokokawa
authors.forename: T
authors.initials: T
authors.lastname: Takeda
mesh_terms: D000527:Alprostadil / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis*; D003907:Dexamethasone / Q000494:pharmacology*; D066298:In Vitro Techniques; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D051381:Rats; D011982:Receptors, Prostaglandin / Q000187:drug effects / Q000378:metabolism*; D018078:Receptors, Prostaglandin E; D012077:Renal Artery / Q000378:metabolism
chemical_list: D011982:Receptors, Prostaglandin; D018078:Receptors, Prostaglandin E; D003907:Dexamethasone; D000242:Cyclic AMP; D000527:Alprostadil