Cyclic AMP stimulates SS and AA RBC adhesion to laminin in a PKA-dependent manner.

SS RBCs (A) or AA RBCs (B) were treated with 36 nM PKA inhibitor (PKAI), for 1 hour, 180 μM of the stable cAMP analog dibutyryl cAMP (db cAMP) for at least 1 hour, or a combination of both as indicated. Adhesion to laminin was measured in the flow adhesion assay (“Materials and methods”). Baseline adhesion is set at 1, and fold change from baseline is indicated. The absolute number of RBCs adhering under basal conditions is shown above the baseline bar of each graph.