Fig. 1. Cyclic AMP inhibits LBP actin assembly. Effects of cAMP (A) and SQ 22536 (B), on the in vitro de novo actin assembly of latex bead phagosomes isolated by flotation (after 1 hour pulse and 1 hour chase) from J774A.1 mouse macrophages, at low (0.2 mM) and high (5 mM) ATP concentrations. (C) Effect of cAMP-modulating drugs on actin nucleation. Results represent means ± s.d. from three independent experiments. Asterisks indicate significance as determined by the Student's t-test: ^*P<0.05; ^**P<0.01 compared with levels in the control.