title: Increased vascular permeability produced by human platelet granule cationic extract.
abstract: A cationic protein extract obtained from isolated human platelet granules increased vascular permeability in mouse and rabbit skin. The permeability-enhancing effect was not inhibited by soybean trypsin and pancreatic trypsin inhibitor, methylsergide maleate, carboxypeptidase B, and C[unk]1 inactivator. Permeability-enhancing activity was blocked by prior treatment of challenged animals with antihistamine. The nondializable relatively heat-stable cationic granule protein extract possessed potent mastocytolytic activity. The experiments described suggest that human platelets exert a permeability-enhancing effect by lysosomal release of cationic proteins which cause histamine release from adjacent tissue mast cells.
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000032:analysis*; D002268:Carboxypeptidases / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004586:Electrophoresis; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D006801:Humans; D007477:Ions; D008247:Lysosomes / Q000032:analysis; D008298:Maleates / Q000494:pharmacology; D008407:Mast Cells / Q000187:drug effects; D008784:Methysergide / Q000494:pharmacology; D051379:Mice; D011506:Proteins / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D011817:Rabbits; D012867:Skin / Q000098:blood supply; D013025:Glycine max; D014020:Tissue Extracts / Q000494:pharmacology*; D014357:Trypsin / Q000494:pharmacology; D014361:Trypsin Inhibitors / Q000494:pharmacology
chemical_list: D006634:Histamine H1 Antagonists; D007477:Ions; D008298:Maleates; D011506:Proteins; D014020:Tissue Extracts; D014361:Trypsin Inhibitors; D002268:Carboxypeptidases; D014357:Trypsin; D008784:Methysergide