Action of AR-L 115 BS on myocardial oxygen consumption, cardiac performance and vascular resistance and capacitance.

2-[(2-Methoxy-4-methylsulfinyl)phenyl]-1H-imidazo[4,5-b]-pyridine (AR-L 115 BS) (0.1--1.0 mg/kg i.v.) exerted positive inotropic and chronotropic actions without inducing marked elevations of myocardial oxygen consumption in anaesthetized dogs. Doses between 0.5 and 5.0 mg/kg i.v. reduced peripheral resistance by a direct vasodilating activity and increased venous capacity. Stroke volume and cardiac output were only slightly influenced by the drug. Residual and end-diastolic left ventricular volumes were reduced and ejection fraction was increased.