Rp-cAMPS sodium salt, a cAMP analog, is a potent, competitive cAMP-induced activation of cAMP-dependent PKA I and II (Kis of 12.5 μM and 4.5 μM, respectively) antagonist. Rp-cAMPS sodium salt is resistant to hydrolysis by phosphodiesterases[2].IC50 & Target: Ki: 6.05 μM (PKA I) and 9.75 μM (PKA II)In Vitro: A membrane-permeable competitive cAMP antagonist (Rp-cAMPS) that blocks PKA activation by binding to the regulatory subunits without dissociating the kinase holoenzyme also inhibits synaptic plasticity but has no effect on normal synaptic transmission[2].In Vivo: Rp-cAMPS (10 μM, 15 min) decreases the monosynaptic EPSCs evoked at the PB-CeLC and BLA-CeLC synapses in slices from arthritic rats but not in control neurons from normal animals. The inhibitory effect of Rp-cAMPS is significant compared to predrug (ACSF) control values obtained in the same neurons[2].