Aim: To investigate the effects of NPPB, a chloride channel blocker, on proliferation of mesangial cells.
Methods: Cell proliferation was determined by measuring cell number and 3H-thymidine incorporation. The LDH activity released from these cells was measured as evaluation of cell viability. The phase of cell cycle was detected by flow cytometry.
Results: Cell proliferation assays showed that treatment with both NPPB (50 and 25 micromol x L(-1)) and in hypertonic media (100% increased osmolarity with D-mannitol ) significantly reduced the number of human MC and 3H-thymidine incorporation in a dose-dependent manner. But the LDH activity was not significantly altered in the treatment with 50 micromol x L(-1) NPPB. Flow cytometry experiments showed that 50 and 25 micromol x L(-1) NPPB arrested (84.2 +/- 2.4) % and (80.8 +/- 2.9) % of cells at G0/G1 stage, versus (70.5 +/- 1.4) % of control cells. Conclusion NPPB suppresses cell proliferation and produces growth arrest at G0/G1 phase in human MC by a mechanism probably associated with changes in cell volume.