title: Desensitisation of human platelets against stimulation by thromboxane mimics--reduction in receptor capacity and loss of functional response.
abstract: Number and affinity of thromboxane A2/PGH2 receptors on gel-filtered human platelets was determined using the receptor antagonist 3H-SQ 29548 as a tracer compound. Preincubation of platelet rich plasma (PRP) with U 46619 reduced receptor number to 31% of control platelets without affecting the affinity (2 x 10(-9) mol/l). Pretreated platelets lost their reactivity to stimulation by U 46619 but not to thrombin within 3 h. It is concluded that preincubation of platelets leads to a homologeous platelet desensitisation and down regulation of thromboxane receptors.
authors: Biochemical Pharmacology, Research Laboratories of Schering AG, Berlin.
authors: K H
authors: KH
authors: Thierauch
authors: D
authors: D
authors: Gabriel
authors: G
authors: G
authors: Prior
authors: E
authors: E
authors: Schillinger
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic; D011464:Epoprostenol / Q000494:pharmacology; D005231:Fatty Acids, Unsaturated; D006801:Humans; D006834:Hydrazines / Q000097:blood*; D016285:Iloprost; D007700:Kinetics; D010974:Platelet Aggregation / Q000187:drug effects; D011449:Prostaglandin Endoperoxides / Q000097:blood*; D011450:Prostaglandin Endoperoxides, Synthetic / Q000097:blood* / Q000494:pharmacology*; D044262:Prostaglandin H2; D011463:Prostaglandins H / Q000097:blood*; D011982:Receptors, Prostaglandin / Q000502:physiology*; D013928:Thromboxane A2 / Q000037:antagonists & inhibitors / Q000097:blood*
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D005231:Fatty Acids, Unsaturated; D006834:Hydrazines; D011449:Prostaglandin Endoperoxides; D011450:Prostaglandin Endoperoxides, Synthetic; D011463:Prostaglandins H; D011982:Receptors, Prostaglandin; D044262:Prostaglandin H2; D013928:Thromboxane A2; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; C045749:SQ 29548; D011464:Epoprostenol; D016285:Iloprost