[Effects of inhalation of several organic solvents on left ventricular dp/dt]

Effects of inhalation of several organic solvents on left ventricular contractility were investigated by using left ventricular dp/dt in anesthetized dogs. The first derivative of the left ventricular pressure was obtained by an electronic differentiating circuit and recorded continuously. As organic solvents, 1,1,1-trichloroethane (1,1,1-TCE), trichloroethylene, tetrachloroethylene, toluene, m-xylene and trichloro-trifluoroethane (FC-113) were used in this study. Each solvent was separately inhaled for a period of approximately 2 min. In the acute inhalation experiments, peak dp/dt that was the maximal left ventricular dp/dt decreased following inhalation of each organic solvent. The threshold concentration of 1,1,1-TCE, trichloroethylene, tetrachloroethylene, toluene, m-xylene and FC-113 required to decrease peak dp/dt was approximately 0.2%, 0.15%, 0.2%, 0.38%, 0.35% and 0.35%, respectively. These results indicated that the decrease in peak dp/dt was induced following inhalation of each solvent, but threshold concentration of the solvents to produce decrease in peak dp/dt was different. Inhalation of organic solvents of higher concentrations markedly decrease peak dp/dt. A dose response relationship was observed between decrease in peak dp/dt and concentration of the solvent greater than the threshold level. The degree of decrease in peak dp/dt following inhalation differed by kind of solvents with the greatest decrease in peak dp/dt being induced by tetrachloroethylene inhalation.