title: Human alpha-thrombin induces phosphoinositide turnover and Ca2+ movements in cultured human umbilical vein endothelial cells.
abstract: This report shows that purified human alpha-thrombin was able to stimulate a rapid and transient formation of water-soluble phosphorylated 3H-inositols in cultured human umbilical vein endothelial cells (HUVEC) prelabelled with 3H-inositol. A parallel breakdown and resynthesis of 3H-inositol-containing phospholipids was observed. Simultaneously, thrombin induced a transient increase of intracellular free Ca2+[( Ca2+]i), as measured from increased fluorescence of quin2 loaded cells. Phosphoinositide turnover and Ca2+ mobilization showed a similar dependence on thrombin dose. [Ca2+]i rise resulted from both influx from extracellular medium and redistribution from intracellular storage sites. On the other hand thrombin-induced phosphoinositide hydrolysis was not dependent on [Ca2+]i rise. [Ca2+]i elevation might be, at least partially, a consequence of increased phosphoinositide turnover, as suggested by [Ca2+]-mobilizing activity of inositol-trisphosphate in other cells.
authors.affiliation: Istituto Mario Negri, Milano, Italy.
authors.forename: M G
authors.initials: MG
authors.lastname: Lampugnani
authors.forename: M
authors.initials: M
authors.lastname: Pedehovi
authors.forename: E
authors.initials: E
authors.lastname: Dejana
authors.forename: D
authors.initials: D
authors.lastname: Rotilio
authors.forename: M B
authors.initials: MB
authors.lastname: Donati
authors.forename: F
authors.initials: F
authors.lastname: Bussolino
authors.forename: G
authors.initials: G
authors.lastname: Garbarino
authors.forename: D
authors.initials: D
authors.lastname: Ghigo
authors.forename: A
authors.initials: A
authors.lastname: Bosia
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004533:Egtazic Acid; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D004987:Ethers / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D015759:Ionomycin; D010716:Phosphatidylinositols / Q000378:metabolism* / Q000502:physiology; D013917:Thrombin / Q000502:physiology*; D014471:Umbilical Veins / Q000166:cytology / Q000378:metabolism* / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D004987:Ethers; D010716:Phosphatidylinositols; D004533:Egtazic Acid; D015759:Ionomycin; D013917:Thrombin; D002118:Calcium