title: Stimulation of the phosphoinositide signalling system as a possible mechanism for glucocorticoid action in blood pressure control.
abstract: Cortisol stimulates the phosphoinositide signalling system in smooth muscle cells of the rat aorta. After stimulation of the cells with cortisol, epinephrine or both compounds, inositol-1,4,5-trisphosphate concentrations were analysed by standardized ion-exchange chromatography procedure. A 15-min stimulation with physiological concentrations of cortisol (0.02-5.0 microgram/ml) led to a dose-dependent increase of the inositol trisphosphate concentrations (up to 500%) and also to a translocation of the calcium- and lipid-dependent protein kinase C activity from the cytosolic to the membranous compartment. Incubation of smooth muscle cells with epinephrine (10(-9) to -5 mol/l) did not lead to an increase in the inositol trisphosphate concentrations. However, after pre-incubation with an average dose of cortisol (0.2 microgram/ml) the inositol trisphosphate response was potentiated by 10(-7) mol/l epinephrine. Our results suggest that stimulation of the phosphoinositide system is a still unknown mechanism of glucocorticoid action in smooth muscle cells, which could influence intracellular free calcium and thus vascular reactivity and blood pressure.
authors.affiliation: Department of Internal Medicine, University Hospital, Zürich, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Steiner
authors.forename: E
authors.initials: E
authors.lastname: Vogt
authors.forename: R
authors.initials: R
authors.lastname: Locher
authors.forename: W
authors.initials: W
authors.lastname: Vetter
mesh_terms: D000818:Animals; D001794:Blood Pressure; D004075:Diglycerides / Q000502:physiology; D004837:Epinephrine / Q000494:pharmacology; D006854:Hydrocortisone / Q000494:pharmacology*; D066298:In Vitro Techniques; D007295:Inositol Phosphates / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000502:physiology*; D010716:Phosphatidylinositols / Q000502:physiology*; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats
chemical_list: D004075:Diglycerides; D007295:Inositol Phosphates; D010716:Phosphatidylinositols; D011493:Protein Kinase C; D006854:Hydrocortisone; D004837:Epinephrine