Perchloroethylene: Effects on Body and Organ Weights and Plasma Butyrylcholinesterase Activity in Mice

Abstract

The effects of continuous and intcrmittent inhalation of perchloroethylene (PCE) on plasma butyrylcholinesterase (BuChE) activity, organ weights, liver morphology and motor activity in mice (strain NMRI) were tested. PCE exposure increased plasma BuChE activity in a time-and concentration dependent manner in both sexes. The increase was statistically significant at 37 p.p.m. in animals continuously exposed for 30 days. BuChE increased approximately 1.5 times in females and 2.5 times in males after 120 days exposure to 150 p.p.m. After rehabilitation of animals exposed for 30 days to IS0 p.p.m., BuChE levels returned to normal. Liver weight also increased in a time and concentration dependent manner. Both sexes exhibited significant liver enlargement at 9 p.p.m. The increase was about 2.3 in females and 1.9 in males after continuous exposure to 150 p p m . for 120 days. After rehabilitation (120 days) of animals exposed to 150 p.p.m. for 30 days, a 10% increase still remained. A decrease in body weight gain was seen in both sexes after exposure to concentrations above 75 p.p.m. Female kidney weight was slightly increased. No clear effect on spleen weight could be detected. When the same time-weighted average conccntration was uscd, intermittent exposure for 30 days had similar effects on livcr weight and BuChE activity as continuous exposure, even when exposures lasted for only one hour per day. Liver cell morphology was changed after PCE exposure. The alterations could be observed already at 9 p.p.m. but disappeared after rehabilitation.

Physicochemical properties

“…When NMRI mice were exposed to 0, 9, 37, 75, or 150 ppm tetrachloroethylene continuously for 30 days (Kjellstrand et al 1984), exposed mice developed hepatocellular vacuolization and enlargement. Lesions were observed at 37 ppm and were noted to be most pronounced at exposures to 75 and 150 ppm; further details were not provided.…”

“…Lesions were observed at 37 ppm and were noted to be most pronounced at exposures to 75 and 150 ppm; further details were not provided. Relative liver weights were not calculated; however, absolute liver weights were significantly elevated at all exposure concentrations and remained elevated 120 days following exposure to 150 ppm (Kjellstrand et al 1984). In a 13-week study, male mice exposed to ≥200 ppm tetrachloroethylene exhibited mitotic alterations in the liver, while both sexes had leukocytic infiltrations, centrilobular necrosis, and bile stasis at ≥400 ppm (NTP 1986).…”