Cytogenetic effects in the peripheral lymphocytes and kidney cells of rats exposed to 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) orally on three consecutive days.

We reported previously that 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)- furanone (MX), a chlorine disinfection by-product in drinking water, induces sister-chromatid exchanges (SCEs) in the peripheral lymphocytes of male and female rats after subchronic exposure. In the present study, we found that the peripheral lymphocytes of male rats exposed to MX (25-150 mg/kg) by gavage on three consecutive days showed a significant dose-related increase in chromosomal damage measured as micronuclei, in addition to SCEs. Moreover, MX produced a significant dose-related increase in SCEs in the kidney cells of the exposed rats. The magnitude of the genotoxic responses observed was relatively weak. The finding is, however, consistent with the known pharmacokinetic distribution of MX in the rat after oral dosing.