Effects of RS-1893, a novel cardiotonic agent, on central and peripheral hemodynamics in anesthetized rats.

After the use of two radionuclides in the tracer microspheres technique in the rat was verified, we examined the central and peripheral hemodynamic effects of RS-1893, an orally active cardiotonic agent. An intravenous infusion of RS-1893 at a dose of 3 micrograms/kg/min gradually decreased blood pressure and increased heart rate and cardiac output. Blood flows in the kidney and stomach were increased. There was no organ in which blood flow was decreased despite the fall in blood pressure. These data suggest that RS-1893 dilates blood vessels in the whole body, especially in the kidney and stomach.