Hepatotoxic potency of various chlorinated hydrocarbon vapours relative to their narcotic and lethal potencies in mice

Abstract

Hepatic damage was determined in mice by serum glutamic-pyruvic transaminase (SGPT) activity 24 hours following single exposures to the vapor concentrations of carbon tetrachloride, chloroform, 1,1,2-trichloroethane, tetrachloroethylene, trichloroethylene, dichloromethane, and 1,1,1-trichloroethane expected to kill 50% of the animals in 9–12 hours of continuous exposure. A median effective exposure duration for an increase in SGPT activity was calculated and expressed as a ratio of the median effective exposure durations for lethality and anesthesia. The ratios obtained for each agent were then ranked and used to illustrate the capacity of each compound for inducing liver damage relative to anesthesia and lethality. Carbon tetrachloride and chloroform were found to be potent hepatotoxins inducing liver damage prior to the onset of anesthesia. 1,1,2-Trichloroethane is a moderate hepatotoxin that requires exposure durations long enough to induce anesthesia before causing hepatic damage. The remaining compounds studied required exposure durations approaching those or longer than those necessary to cause death before hepatic damage could be ascertained by a significant SGPT elevation. These data are not necessarily indicative of the hepatic damage that may be induced by repeated low level exposures.