Imazodan, a small molecule compound with positive inotropic activity, is a selective type III phosphodiesterase inhibitor and can be used to study heart failure.

Vesnarinone (Arkin) (INN) is a mixed phosphodiesterase 3 inhibitor and ion-channel modifier that has modest, dose-dependent, positive inotropic activity, but minimal negative chronotropic activity. It also suppresses cell proliferation and induces apoptosis by inducing the expression of p21, an inhibitor of cyclin-dependent kinase activity in p53-mediated cell cycle arrest.

Astragaloside may protect against brain contusion and neuronal apoptosis after TBI by attenuating microglia activation in male rats. Astragalosides-induced apoptosis in NB4 cells may be associated with down-regulation of the expression of BCL-2 and NF-κB,

Amrinone (Inocor) is a positive inotropic cardiotonic (cardiotonic agent) with vasodilator properties, phosphodiesterase 3 inhibitory activity.

Inamrinone lactate is a positive inotropic cardiotonic with vasodilator properties, phosphodiesterase inhibitory activity, and the ability to stimulate calcium ion influx into the cardiac cell.

Doxaminol is a synthetic partial beta-adrenergic agonist with sympathomimetic activity. Doxaminol may bind to and stimulate beta-1-adrenergic receptors located in the myocardium. As a result, it leads to a positive inotropic effect and increases in cardiac output.

LY 249933 is a cardioselective 1, 4-dihydropyridine with positive inotropic activity.

Olprinone Hydrochloride, also known as Loprinone, is a phosphodiesterase (PDE) 3 potent inhibitor, exhibiting IC50 values of 150, 100, 0.35, and 14 μM for PDE1, PDE2, PDE3, and PDE4, respectively. It is utilized in heart failure research for its positive inotropic and vasodilative properties. It also exhibits anti-inflammatory activity [1] [2].

Enoximone sulfoxide is a selective phosphodiesterase III (PDE3) inhibitor with vasodilating and positive inotropic activity that does not cause changes in myocardial oxygen consumption. Enoximone prevents the degradation of cAMP by PDE, which prolongs signal transduction and its subsequent effects. It is used in patients with congestive heart failure.

Astragaloside, one of the main active ingredients in Astragalus membranaceus.