Equilibrium between adenylyl cyclase and phosphodiesterase patterns adrenergic agonist dose-dependent spatiotemporal cAMP/protein kinase A activities in cardiomyocytes.

ABSTRACT: Beta-adrenergic receptor induces cAMP/Protein kinase A (PKA) activation to regulate cardiac contraction. Using real-time fluorescence resonance energy transfer imaging for highly sensitive detection of cAMP and PKA activities, we show two distinct phases in isoproterenol dose-dependent responses in cardiomyocytes: a transient and dose-dependent increase in cAMP and PKA activities at lower concentrations from 10(-12) to 10(-8) M; and a saturated initial increases at higher concentrations from 10(-8) to 10(-5) M followed by a rapid decrease to different levels that were later sustained in a dose-dependent manner. The dose-dependent temporal responses are patterned by equilibrium between receptor-activated adenylyl cyclase (AC) and phosphodiesterase (PDE). At lower concentrations, cAMP is pro

SUBMITTER: De Arcangelis V 

PROVIDER: S-EPMC2939479 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature