A Xanthine Derivative Denbufylline Inhibits Negative Inotropic Response to Verapamil in Guinea Pig Ventricular Papillary Muscles, Independent of Its Phosphodiesterase Inhibitory Activity

[摘要] References(8)A phosphodiesterase (PDE) III inhibitor, amrinone, inhibited both the negative inotropic actions of verapamil and nicardipine in guinea pig ventricular papillary muscle; this effect was canceled by the protein kinase A inhibitor H-89. The PDE IV inhibitor 1, 3-di-n-butyl-7-(2’-oxopropyl)xanthine (denbufylline), which elicited a negative inotropic action by itself, attenuated the action of verapamil up to 10 μM, without any interaction, with nicardipine. The attenuation by denbufylline was not influenced by H-89. This suggests that in the ventricular papillary muscle, denbufylline acts on some verapamil-sensitive site(s) in the membrane and interferes with the calcium channel function without involvement of its PDE inhibitory activity.

[学科分类] 药理学

[关键词] Denbufylline;Negative inotropy;Calcium channel