Rp-cAMPS has ho effect on adenosine A 1 receptors in guinea-pig cardiomyocytes

Abstract

Rp-cAMPS, a protein kinase A inhibitor, is used in the investigation of the cAMP-dependent systems. A report by Musgrave et al. has suggested that Rp-cAMPS may also act on adenosine receptors. To determine whether this occurs in guinea-pig ventricular myocytes, Rp-cAMPS was applied in the presence and absence of DCPCX, an adenosine A receptor antagonist. The isoprenaline-induced response was significantly decreased by Rp-cAMPS and the effect was not altered by the presence of DCPCX. Therefore Rp-cAMPS has no effect on cell contraction via adenosine A1 receptors and can reliably be used to investigate cyclic AMP-dependent systems in isolated cardiac myocytes.

P2Y2 Purinergic and M3 Muscarinic Acetylcholine Receptors Activate Different Phospholipase C-β Isoforms That Are Uniquely Susceptible to Protein Kinase C-dependent Phosphorylation and Inactivation

“…The ability of PKA to mediate agonist-induced phosphorylation of PLC-␤3 was tested using the highly specific PKA antagonist, Rp-CAMPS. Concentrations of Rp-CAMPS well above those known to completely block PKA activation (28,29) had no effect on the carbacholinduced phosphorylation of PLC-␤3 at (Fig. 4).…”