M Bjerkemo

Trichloroethylene: Effects on body and organ weights in mice, rats and gerbils

The influence of continuous inhalation of 150 ppm trichloroethylene (TCE) on body, liver, spleen, and kidney weights in rats, mice, and mongolian gerbils was tested. An age dependent decrease in body weight gain was observed in female rats exposed to TCE. All 3 species showed liver enlargement caused by the exposure. The effect was much more pronounced in mice, in which the increase was 60--80%, than in rats and gerbils where it was only 20--30%. After the end of the TCE-exposure the liver weights of the mice decreased rapidly. After 5 days of rehabilitation the weight was only 10--20% higher than that of the controls. This difference persisted for at least 25 days. The spleen weight appeared unaffected or somewhat smaller in TCE-exposed animals of all species. An increased kidney weight (15%) was observe din TCE-exposed gerbils. This effect was less pronounced in mice and rats. Effects on the liver have earlier been seen only after exposure to concentrations much higher than that used in the present study. This difference in results is proposed to be due to the different schedules used for the exposure.

Effects of Trichloroethylene inhalation on acid phosphatase in rodent brain

Rats, mice and gerbils were continuously exposed to 150 ppm trichloroethylene (TCE) for 30 days. In all three species, there was a marked increase in liver weight. In mice the weight increased more (86%) than in rats and gerbils (20%). After exposure the activity of acid phosphatase, a lysosomal marker enzyme, was tested in different brain areas, using a system which had a limit of detection of +/- 10-15%. In most areas no significant influence was found. However, in the brain stem of mice and gerbils the phosphatase activity increased by approx. 10%.

Sensitivity of mongolian gerbils to trichloroethylene exposure during neonatal growth

Continuous exposure of young mongolian gerbils to trichloroethylene (230 ppm) was started at different times during the first month of life. The onset of exposure was accompanied by an increased number of deaths among the pups and by an immediate reduction in growth rate. The proportion of dead pups was greatest when exposure was started at birth, and decreased rapidly with increasing age at onset of exposure. Growth rate was partially restored approx. 1 week after the onset of exposure. After weaning the effect of the exposure on growth decreased, and the variation in the effect among different litters was considerably reduced. The enhanced sensitivity of the pups to trichloroethylene (TCE) exposure is believed to be due to a disturbance in the mother-offspring relationship.