Sp-cAMPS

Sp-cAMPS, a cAMP analog, is potent activator of cAMP-dependent PKA I and PKA II. Sp-cAMPS is also a potent, competitive phosphodiesterase (PDE3A) inhibitor with a Ki of 47.6 µM. Sp-cAMPS binds the PDE10 GAF domain with an EC50 of 40 μM[1][2][3].

Treatment of hepatocytes with Sp-cAMPS, the stimulatory diastereomer of adenosine cyclic 3',5'-phosphorothioate, mimics the response seen with glucagon. The glucagon-stimulated increases in the level of Ca2+ can be mimicked by Sp-cAMPS[4].

In chronic alcohol consumption (CAC) mice, direct infusion of the Sp-cAMPS (1 µg/µL) into the prefrontal cortex significantly improves or impairs, respectively, working memory performance in withdrawn and water animals[5].

[1]. Su H Hung, et al. A new nonhydrolyzable reactive cAMP analog, (Sp)-adenosine-3',5'-cyclic-S-(4-bromo-2,3-dioxobutyl)monophosphorothioate irreversibly inactivates human platelet cGMP-inhibited cAMP phosphodiesterase. Bioorg Chem. 2002 Feb;30(1):16-31. [2]. L Y Wang, et al. Regulation of kainate receptors by cAMP-dependent protein kinase and phosphatases. Science. 1991 Sep 6;253(5024):1132-5. [3]. Ronald JÄger, et al. Activation of PDE10 and PDE11 phosphodiesterases. J Biol Chem. 2012 Jan 6;287(2):1210-9. [4]. P A Connelly,et al. A study of the mechanism of glucagon-induced protein phosphorylation in isolated rat hepatocytes using (Sp)-cAMPS and (Rp)-cAMPS, the stimulatory and inhibitory diastereomers of adenosine cyclic 3',5'-phosphorothioate. J Biol Chem. 1987 Mar 25;262(9):4324-32. [5]. G Dominguez, et al. Rescuing prefrontal cAMP-CREB pathway reverses working memory deficits during withdrawal from prolonged alcohol exposure. Brain Struct Funct. 2016 Mar;221(2):865-77.