Influence of alcohol pretreatment on effects of chloroform in rats

Methanol, ethanol and isopropanol were tested for the ability to change effects of chlorinated hydrocarbons on the alanine aminotransferase (ALAT = GPT; EC 2.6.1.2.) activity in serum of rats. The alcohols were given once orally or repeatedly together with drinking water. After additional i.p. administration of chloroform we found a significant increase of ALAT activities in the order: isopropanol greater than or equal to methanol greater than ethanol, both after single and repeated application of the alcohols. Together with trichloroethene and 1.1.2.2-tetrachloroethane no such elevations were found. The results suggest that different mechanisms of action could be underlying.