Increased uptake of serotonin in platelets from car painters occupationally exposed to mixtures of solvents and organic isocyanates.

Twelve car painters occupationally exposed to mixtures of solvents and organic isocyanates were investigated concerning serotonin uptake in platelets. The data from the exposed workers were compared to data from a reference group consisting of 50 nonexposed volunteers. The mean platelet count in whole blood of the exposed workers was markedly lower than the corresponding value of the reference group. Three workers had values below the lower limit of the 95% tolerance interval of the referents. In both groups the serotonin transport strictly obeyed Michaelis-Menten's simple saturation kinetics. Nine of the twelve exposed workers had uptake rates which were significantly higher (p = 0.05) than those of the referents. The obtained data suggest that the present method may be used to reveal early organ damage, prior to the appearance of clinical symptoms, due to intermittent exposure to organic solvents and isocyanates.