10.1371/journal.pone.0061634.g005 Figure 5 Effects of FSK on cAMP-related parameters and ABCB mRNA expression in mussel haemocytes incubated in vitro. (A) cAMP content; (B) relative PKA activities; (C) relative ABCB mRNA expression. All biological endpoints were assessed after 4 h of exposure to 20 µM FSK. Data are derived from three independent experiments (mean ± SEM); *p<0.05 vs control. Basal PKA activity = 1.12±0.17 nmol/min/mg protein.