Trichloroethylene: further studies of the effects on body and organ weights and plasma butyrylcholinesterase activity in mice.

The effects of continuous and intermittent inhalation of trichloroethylene (TCE) were studied in male and female mice. Plasma butyrylcholinesterase (BuChE) activity, body, liver, kidney and spleen weights were measured. The liver was studied histologically and motor activity measured with doppler radar. Continuous TCE-exposure (37-300 p.p.m.) increased plasma BuChE activity in the males in a time and concentration dependent manner. After 30 days at 37 p.p.m. the increase was about 25%. Exposure to 300 p.p.m. for 30 days increased the activity three times. BuChE activity in females was only slightly influenced even at 300 p.p.m. Liver weight was increased in a time and concentration dependent manner in both sexes. In animals continuously exposed for 30 days to 300 p.p.m., liver weight was roughly twice that of the air-exposed controls. Morphological changes were observed in the liver of TCE-exposed animals. Above 150 p.p.m. kidney weight in both sexes was significantly increased. This effect was more pronounced in the males than in the females. Spleen weight was not influenced by the exposure. Body weight increase was slightly lower in exposed animals. Plasma BuChE activity and liver weight returned to normal when exposure was terminated. Intermittent exposure to short pulses of high concentration of TCE had roughly the same effect on BuChE, body and organ weights as continuous exposure to the same time-weighted average. Motor activity was affected by the intermittent exposure schedules. At 900 p.p.m. decrease in activity was observed. At 3600 p.p.m. motor activity was considerably increased.