title: Wortmannin interferes with thrombin-evoked secondary calcium redistribution in human platelets.
abstract: Wortmannin has previously been reported to inhibit calcium entry in thrombin-stimulated human platelets. We extend these findings by demonstrating that the redistribution of calcium from intracellular stores features two separate, consecutive phases the second of which is selectively abolished by wortmannin. The primary release of calcium from Ins 1,4,5 P3-sensitive stores remains unaffected. Hence, wortmannin is interfering with regulation of any secondary, sustained calcium accumulation in the cytosolic compartment of activated platelets, originating either from intracellular stores or from calcium entry. We assume that wortmannin blocks a common step in receptor-dependent regulation of calcium entry. We assume that wortmannin blocks a common step in receptor-dependent regulation of calcium entry and intracellular calcium circulation.
authors.affiliation: University of Konstanz Faculty of Biology, Department of Biological Chemistry, Germany.
authors.forename: F
authors.initials: F
authors.lastname: von Appen
authors.forename: V
authors.initials: V
authors.lastname: Ullrich
authors.forename: B
authors.initials: B
authors.lastname: Brüne
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D000730:Androstadienes / Q000494:pharmacology*; D001792:Blood Platelets / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D002118:Calcium / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006801:Humans; D017482:Receptors, Thromboxane / Q000819:agonists; D015290:Second Messenger Systems / Q000502:physiology*; D015398:Signal Transduction; D013917:Thrombin / Q000494:pharmacology; D000077191:Wortmannin
chemical_list: D000730:Androstadienes; D004791:Enzyme Inhibitors; D017482:Receptors, Thromboxane; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D013917:Thrombin; D002118:Calcium; D000077191:Wortmannin