Figure 3. Effect of forskolin plus rolipram pre-treatment on TER response. The changes in TER were measured in response to TNF-α (T) with or without pre-treatment with 10 µM forskolin (F) and 50 µM rolipram (R) for 30 min. A: Typical responses. B: Summary of six independent experiments. The % reduction in TER induced by the cytokine is significant when compared to control at >8 h. Pre-treatment with F and R opposes the (TNF-α)-induced reduction in TER after 12 h of exposure. * and ** denotes p<0.001 when comparing the TNF-α-treated group with the control group and the (TNF-α+F+R) -treated group with the TNF-α-treated group, respectively.