thapsigargin and 1-(2-methoxyphenyl)-4-(4-(2-phthalimido)butyl)piperazine

The study was conducted on a human (Jurkat) T cell line, loaded with a Na+ fluorescent probe, SBFI/AM. Serotonin and an agonist of 5-HT3 receptor-channels, 2-methyl-5HT, evoked Na+ influx, whereas the agonists of other serotonergic receptor subtypes, i.e., 5-HT1A and 5-HT1B receptors, failed to induce Na+ influx in these cells. By using 3H-BRL43694, an agonist of 5-HT3 receptor-channels, we characterized 5-HT3 lymphocyte receptors which exhibited a density (Bmax) of 300 +/- 20 fmol/10(6) cells and a Kd of 30 nM in Jurkat T cells. The T-cell 5-HT3 receptor-channel is not regulated either by the protein kinase C or by the free intracellular calcium concentrations as the agents known to activate the PKC and to induce increases in intracellular free calcium concentrations failed to influence the free intracellular Na+ concentrations, [Na+]i, in these cells. Furthermore, an increase in [Na+]i, induced by 2-methyl-5HT, via 5-HT3 receptor-channels seems to stimulate T-cell activation by facilitating the progression of T cells from S to G2/M phase of the cell cycle.

Topics: 8-Hydroxy-2-(di-n-propylamino)tetralin; Calcium Signaling; Cell Cycle; Enzyme Activation; Granisetron; Humans; Ion Channel Gating; Ion Transport; Jurkat Cells; Lymphocyte Activation; Metoclopramide; Neoplasm Proteins; Phytohemagglutinins; Piperazines; Protein Kinase C; Quinoxalines; Receptor, Serotonin, 5-HT1B; Receptors, Serotonin; Receptors, Serotonin, 5-HT1; Receptors, Serotonin, 5-HT3; Ryanodine; Serotonin; Serotonin Antagonists; Serotonin Receptor Agonists; Sodium; Sodium Channels; T-Lymphocytes; Thapsigargin