Na+/H+ exchange activity induced by thrombin is not inhibited by protein kinase inhibitors, staurosporine, K-252a, H-7 and sphingosine, in human platelets.

In human platelets stimulated with thrombin (40 mU/ml), Na+/H+ exchange activity [the ethylisopropylamiloride (EIPA)-sensitive increase of cytoplasmic pH (pHc)] and protein kinase C (PKC) activity [phosphorylation of 47 kDa protein (P47), a substrate for PKC] were determined in the presence of protein kinase inhibitors, staurosporine (0.05-1 microM), K-252a (0.5-10 microM), H-7 (100 microM) and sphingosine (20-40 microM).

Changes of platelet functions by extracellular sodium ion.

Effects of extracellular Na+ on platelet responses were examined. Cytoplasmic pH decreased by stimulation with thrombin, TPA and AA in Na(+)-containing buffer as well as in Na(+)-free buffer. Thrombin-induced aggregation and serotonin release were higher in Na(+)-containing buffer, but TPA- and A23187-induced responses exhibited lower values.

Mechanisms of blood coagulation induced by latex particles and the roles of blood cells.

Latex particles with highly negative or positive charges shortened the clotting time of whole blood and platelet-rich plasma and activated platelet factor 3. Platelet-poor plasma was clotted by the particles with a highly negative charge, but not by those with a positive charge, except hydrophobic particles. Blood coagulation by positively-charged particles was attributed to platelet activation.

De novo protein synthesis is essential to human interferon gamma gene expression by the stimulation with polyI:polyC.

Transcription of human interferon (IFN) gamma gene is induced in human peripheral lymphocyte nylon-nonadherent cells (NNA cells) by double strand RNA poly I:poly C [(1985) J. Interferon Res. 5, 77-84].