title: Reduction in rat mesentery mast cell staining after degranulation by protamine. A competitive antagonism.
abstract: Degranulation of rat mesentery mast cells by increasing concentrations of protamine causes a parallel decrease in the numbers of mast cells stained with toluidine blue or with berberine sulfate. No decrease in mast cell numbers occurs when degranulation is inhibited. Since protamine does not enter into non stimulated mast cells, these results suggest that this reduction in mast cell numbers is caused by the binding of protamine to the anionic sites of heparin of exocytosed granules thereby preventing their staining. There seems to be a competitive antagonism between protamine and toluidine blue at the anionic sites of heparin for increasing concentrations of toluidine blue progressively reverse the reduction in mast cell numbers.
authors.affiliation: Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brasil.
authors.forename: C
authors.initials: C
authors.lastname: Augusto
authors.forename: L O
authors.initials: LO
authors.lastname: Lunardi
authors.forename: I
authors.initials: I
authors.lastname: Vugman
mesh_terms: D000818:Animals; D001665:Binding Sites; D005260:Female; D006493:Heparin / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D008407:Mast Cells / Q000187:drug effects* / Q000378:metabolism; D011479:Protamines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013194:Staining and Labeling; D014048:Tolonium Chloride
chemical_list: D011479:Protamines; D014048:Tolonium Chloride; D006493:Heparin