| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥1,400,000 (Direct Cost: ¥1,400,000)
|
|---|
| Research Abstract |
Effects of organic solvents inhalation on left ventricular contractility were studied in anesthetized dogs. 1,1,1-trichloroethane(1,1,1-TCE), trichloroethylene, tetrachloroethylene, toluene, m-xylene and trichloro-trifluoroethane were used in this experiments.
In acute inhalation experiments, peak dp/dt that obtained by the first derivative of the left ventricular pressure decreased follwing each organic solvent inhalation. Moreover, left ventricular pressure, dp/dt/P40 and V max decreased simultaneously following 1,1,1-TCE inhalation of higher concentrations. Heart rate recorded simultaneously increased with relatively low 1,1,1-TCE concentrations and decreased with higher concentrations. Increase or decrease in peak dp/dt was observed to be dependent on changes in heart rate induced by right atrial pacing. Thus, the degree of the decrease in peak dp/dt during pacing experiments was compared with those of nonpacing experiments. At higher concentrations, the decreases in peak dp/dt during pacing was slightly less than in the nonpacing experiments. In a subsequent experiments, direct effect to the heart in the decrease in peak dp/dt was investigated following higher 1,1,1-TCE concentrations. Degrees of the peak dp/dt was compared between groups with vagi-sympsthetic intact and groups with denernation. degree of the decreases in peak dp/dt were same in both groups following 1,1,1-TCE inhalation.
It is suggested that left ventricular contractility in the period of isovolumetric contraction decreased following organic solvents inhalation, and furtuer suggested that heart rate and direct effects to the heart may be related to the decrease in left ventricular contractility following organic solvants inhalation.
|
