Activation of Na+/H+ exchange in human platelets stimulated by thrombin and a phorbol ester.
We have investigated changes in cytoplasmic pH (pHi) in activated human platelets, using the fluorescent probe 2,7-biscarboxyethyl-5(6)-carboxyfluorescein. Stimulation of platelets by thrombin or 12-O-tetradecanoylphorbol 13-acetate increased pHi by about 0.11 pH unit above the resting value. This increase in pHi depended on the presence of external Na+ and was inhibited by ethylisopropylamiloride. The data suggest that protein kinase C mediates Na+/H+ exchange in human platelets.
D000584:Amiloride / Q000031:analogs & derivatives / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D007474:Ion Exchange; D012964:Sodium / Q000097:blood*; D013268:Stimulation, Chemical; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013917:Thrombin / Q000494:pharmacology*
D000584:Amiloride; D012964:Sodium; D013917:Thrombin; D013755:Tetradecanoylphorbol Acetate; C039614:ethylisopropylamiloride