Figure 9
Effect of MG132 on intracellular calcium ([Ca 2+ ] i ) mobilisation by the hIP. HEK.hIP cells were pretreated with MG132 (10 μM) for 3 hr, 6 hr or 12 hr prior to harvesting, where untreated (0 hr) or vehicle-treated (0.001% DMSO, 12 hr) cells served as controls. Cells were preloaded with Fura2/AM and stimulated with 1 μM cicaprost. In all cases, mean maximal changes in intracellular calcium mobilised (Δ[Ca2+] i (nM) ± S.E.M.) were determined from at least four independent experiments. Actual mean Δ[Ca2+] i ± S.E.M. were: 0 hr, 141.2 ± 5.76 nM; vehicle, 12 hr, 145.0 ± 10.3 nM; MG132, 3 hr, 89.0 ± 4.11 nM; MG132, 6 hr, 91.8 ± 5.8 nM; and MG132, 12 hr, 70.4 ± 4.48 nM. Typically, actual baseline [Ca2+] levels in HEK.hIP cells were 10-15 nM. In all cases, mean maximal changes in intracellular calcium mobilised (Δ[Ca2+] i (nM) ± S.E.M.) were determined from at least four independent experiments. **, p < 0.01 indicates that the mean Δ[Ca2+] i was significantly reduced in the presence of MG132 compared to those levels in untreated cells at the specified time points (3, 6 & 12 hr).