Cell-permeable cAMP analog; acts as a competitive antagonist of cAMP-induced activation of PKA (IC50 = 11 - 16 μM) by interacting with cAMP binding sites on the regulatory subunits. Resistant to hydrolysis by phosphodiesterases. Also available as part of the PKA Tocriset™. Enantiomer cAMPS-Sp, triethylammonium salt (Cat. No. 1333) also available.