Figure 8. Effect of elevated cAMP on the organization of microtubules and PAMR. Cells were treated with 20 ng/ml TNF-α (T) for 6 h and where indicated were co-treated with 10 µM forskolin (F) and 50 µM rolipram (R). A-D: Organization of microtubules. In untreated cells (Control, A), microtubules exist as characteristic fibrillary extensions from around the nucleus to the cell periphery (shown by arrows). It is undisturbed by F and R (B). Treatment with TNF-α (C) induced microtubule disassembly characterized by the loss of as well as condensation of fibrillary extensions (shown by arrows), which was opposed by co-treatment with F and R (D). E-H: Organization of PAMR. In untreated cells (Control, E), the characteristic organization of cortical actin with intact PAMR is observed (shown by arrows). It is undisturbed by F and R (F). Treatment with TNF-α induced disruption of PAMR (G) (shown by arrows), which was opposed by co-treatment with F and R (H). All the images shown are representative of at least three independent experiments.