New aspects of DNA adduct formation by the carcinogens crotonaldehyde and acetaldehyde.

Abstract

Crotonaldehyde and acetaldehyde are mutagenic in S. typhimurium and other systems used for detection of genetic damage (IARC, 1985; 1995; 1999). Crotonaldehyde induces altered liver cell foci, neoplastic nodules, and hepatocellular carcinoma upon oral administration to F344 rats (Chung et al, 1986; IARC, 1995). Acetaldehyde causes tumors of the respiratory tract in rats and hamsters upon exposure by inhalation (IARC, 1985; 1999). Crotonaldehyde and acetaldehyde are commonly detected in cigarette smoke, mobile source emissions and other products of thermal degradation (IARC, 1985; 1995; 1999). Their concentrations in cigarette smoke are far higher, while their carcinogenic activities are considerably lower, than those of polycyclic hydrocarbons, aromatic amines and N-nitrosamines, which are considered to be important carcinogens in cigarette smoke (IARC, 1985; 1986; 1995; 1999). Crotonaldehyde and acetaldehyde are also important endogenous compounds. Crotonaldehyde is a product of lipid peroxidation while acetaldehyde is the principal metabolite of ethanol.