Fig. 7. Reactivation of p44ERK under recovery requires PP1/PP2A activity. RTHDF cells were treated with 100 nmol l^–1 calyculin A (Cal. A; an inhibitor of PP1/2) for 2 min prior to treatment. Cell extracts were analysed by western blotting (top) and the immunoreactive bands were quantified (bottom). (A) Effect of calyculin A on normoxic p44ERK activity. (B) Effect of calyculin A on p44ERK phosphorylation after chemical anoxia/recovery (A/R) (N=3, *P<0.05).