CARDIAC AND HEMODYNAMIC-EFFECTS OF S(-)-DPI 201-106 AND (R(+)-DPI201-106 AND OF RACEMIC DPI 201-106 IN CONSCIOUS DOGS

The cardiac and hemodynamic effects of (±)-DPI 201-106 (0.6 mg/kg), S(-)-DPI (0.3 mg/kg), R(+)-DPI (0.3 mg/kg), and their vehicle were compared in chronically implanted conscious dogs. (±)-DPI and S(-)-DPI induced qualitatively and quantitatively similar effects, increasing LV dP/dt, cardiac output and stroke volume and reducing total peripheral resistance. In contrast, R(+)-DPI decreased only stroke volume. It is concluded that (a) the positive inotropic effects of (±)-DPI in vivo are caused by its S(-) enantiomer, and (b) the peripheral vasodilating effects of (±)-DPI may not be linked to the drug's calcium antagonist properties. © 1990.