| 1438028 |
Ben-Haim SA, Ben-Ami H, Hayam G, Taitelman U, Edoute Y: Obidoxime augments the positive inotropic effect of phosphamidon on the isolated working rat heart. Pharmacol Toxicol. 1992 Aug;71(2):127-31.
The present study was designed to determine modulation of the direct inotropic effect of an anticholinesterase organophosphorus compound, phosphamidon, by the reactivator obidoxime. We investigated the effects of phosphamidon (n = 9), obidoxime (n = 5), and their combination (n = 5) on the mechanical and energetic indices of left ventricular function, in the isolated working rat heart model. Phosphamidon at a concentration range of 10 (-6)-10 (-3) M had a positive inotropic effect. Obidoxime at a concentration range of 10 (-6)-10 (-3) M had no significant effect on heart rate, but did have a statistically significant positive inotropic effect on end-systolic pressure, cardiac output, mean left ventricular pressure, and maximal time derivative of left ventricular pressure (dP/dtmax) (P less than 0.01). Perfusion with 10 (-3) M obidoxime caused a 19% increase in left ventricular stroke work and a 31% increase in total pressure-volume area. Perfusion with phosphamidon and obidoxime at concentrations ranging from 10 (-6) to 10 (-3) M resulted in a more intense inotropic response than the separate drug effects. At the highest combined concentrations tested, cardiac output increased by 60%, left ventricular stroke work increased by 100%, and left ventricular total pressure volume area increased by 111% of their control values (P less than 0.001). We conclude that obidoxime augments the positive inotropic effect of phosphamidon on the isolated working rat heart. |
31(0,1,1,1) |