Fig. 5. Effects of okadaic acid pre-treatment on the levels of nuclear cPLA-. (A) Cells (5x10) were seeded onto coverslips and grown to confluency. Cells were then washed with PBS and pre-treated with 1 µM okadaic acid in HEPES/Tyrode's buffer for 30 minutes at 37°C (controls cells were incubated with buffer alone). Cells were then fixed and permeabilised and cPLA- was detected by immunofluorescence microscopy. Bar, 10 µm. (B) Plot showing the change in the level of nuclear intensity (±s.e.m., n=90, data from three independent experiments) in sections taken through control and okadaic acid treated cells.