title: Na+/H+ exchange is not necessary for protein kinase C-mediated effects in platelets.
abstract: The role of Na+/H+ exchange in protein kinase C-mediated effects in platelets was investigated by studying the effect of removal of extracellular Na+ ([Na+]e) on the different responses induced by phorbol 12-myristate 13-acetate (PMA) and 1,2-dioctanoylglycerol (diC8). None of the responses studied, namely, protein phosphorylation, translocation of enzyme activity to the membrane fraction, potentiatory and inhibitory effect on platelet activation ([Ca2+]i, arachidonate and granule release) showed an absolute dependence on [Na+]e. With the exception of dense-granule release, which was clearly potentiated by the removal of [Na+]e and showed a negative correlation with exchanger activity, the other effects of PMA and diC8 were not affected by [Na+]e removal. It is concluded that Na+/H+ exchange is not essential for protein kinase C activation in platelets.
authors.affiliation: Thrombosis Research Unit, Rayne Institute, King's College School of Medicine and Dentistry, London, England.
authors.forename: S
authors.initials: S
authors.lastname: Krishnamurthi
authors.forename: Y
authors.initials: Y
authors.lastname: Patel
authors.forename: W A
authors.initials: WA
authors.lastname: Morgan
authors.forename: C P
authors.initials: CP
authors.lastname: Wheeler-Jones
authors.forename: V V
authors.initials: VV
authors.lastname: Kakkar
mesh_terms: D001345:Autoradiography; D001792:Blood Platelets / Q000187:drug effects / Q000201:enzymology*; D002352:Carrier Proteins / Q000378:metabolism*; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D011506:Proteins / Q000032:analysis; D012701:Serotonin / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D017923:Sodium-Hydrogen Exchangers; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D001620:beta-Thromboglobulin / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D004075:Diglycerides; D011506:Proteins; D017923:Sodium-Hydrogen Exchangers; D001620:beta-Thromboglobulin; C044295:1,2-dioctanoylglycerol; D012701:Serotonin; D012964:Sodium; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate