Milrinone Produces a Positive Inotropy but is not Inhibitory to Gastric ion Transport

Abstract

The cardiac drugs ouabain and milrinone are positive inotropic agents. Since ouabain has inhibitory effects on ion transport in the gastrointestinal tract associated with vasoconstriction and hypoxia, milrinone needed to be tested also. This report indicates that therapeutic levels of milrinone on either side of the isolated stomach wall of the guinea pig has no significant effects on active chloride ion transport or the electrical parameters of the tissue. To verify that milrinone was active in the heart at these same levels, contractility of the isolated heart of the guinea pig was measured. Milrinone significantly increased ventricular pressure and pressure development. Thus milrinone may be expected to exert its inotropic stimulation of the heart during heart failure without compromising gastrointestinal functions.