Accentuation of ursolic acid on muscarinic receptor-induced ANP secretion in beating rabbit atria.

Abstract Aims Ursolic acid has recently been reported to increase both atrial natriuretic peptide (ANP) secretion and mechanical dynamics in rabbit atria. Main methods The present study was designed to clarify the regulatory effects of ursolic acid on the β-adrenergic or muscarinic receptor-mediated changes in ANP secretory and contractile function allowing measurement of atrial dynamics such as pulse pressure, stroke volume, and cAMP efflux in isolated perfused beating rabbit atria. Key findings Pretreatment with ursolic acid significantly attenuated the isoproterenol (β-adrenergic agonist)-induced decrease in ANP secretion and increases in cAMP levels and atrial dynamics. Interestingly, ursolic acid concentration-dependently accentuated the acetylcholine-induced increase in ANP secretion and decrease in pulse pressure in the presence of isoproterenol (p  Significance This implicates for the beneficial effects of ursolic acid in the regulation of cardiovascular and body fluid homeostasis.