Follow-up of the antihemolytic effect of toluene inhalation in rats.

The antihemolytic effects of toluene were studied with inhalation exposures in vivo. At a concentration of 2000 ppm the effect seemed to begin 0.5 h after the onset of exposure, and it ended completely 0.5 h after the end of the exposure. There was no significant change in the mean corpuscular volume (MCV), although it increased at first during and also following the exposure. The antihemolytic effect of different toluene concentrations was also tested with inhalation exposures. The inhalation of 300-2000 ppm of toluene caused a significant antihemolytic effect in a 1-h exposure, but it did not change the MCV. The greatest antihemolytic effect was obtained with a concentration of 1500 ppm of toluene. Our results confirm the assumption that the effect of toluene as a membrane-stabilizing agent is a reversible phenomenon that requires the presence of the agent molecules during the hemolytic process. The antihemolytic effect does not seem to be caused by an increase in the MCV.