Characterization of the taurine transport pathway in A6 kidney cells.

摘要: We investigated the role of taurine in cell homeostasis and characterized transport pathway cultured kidney cells (A6). The concentration A6 varies with osmolarity culture medium, suggesting that participates osmolarity. Under isosmotic conditions, 14C-taurine efflux through apical membranes (aJtaur) was 6–7 times lower than basolateral (bJtaur). hyposmotic aJtaur remained almost unchanged. On contrary, bJtaur increased 8 comparison conditions. In inhibited by 500 mM DIDS, 50 NPPB, 10 two oxonol derivatives DISBAC(2)3 WW-791, 100 ketoconazole. Conversely, 1,9-dideoxyforskolin, tamoxifen, niflumic acid verapamil had no inhibitory effects. Cell volume regulation upon stress also found to be (K0.5 5±1 mM) Nystatin used permeabilize aim further characterize bJtaur. transepithelial fluxes nystatin-treated were linear over concentrations ranging from 3.5 35 mM. Clamping voltage at positive values (serosal side) slightly stimulated transport. Similar time courses 14C-taurine, 36Cl 86Rb under osmotic stimulation followed DIDS inhibition cells. whole patch-clamp experiments, application resulted a strong reversible decrease global Cl? current which stress. Our study indicates control transporting (efflux) is on membranes. addition usual chloride channel blockers, potent blocker swelling-activated current. Using pharmacological approach, we could not distinguish between common or different for taurine.