Verschaeve L, Heikkinen P, Verheyen G, van Gorp U, et al. (2006)
The authors studied the effect of exposure to RFR in rats that were also exposed to 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) in their drinking water. MX is a multi-site carcinogen in Wistar rats when given continuously in their drinking water.
There were 72 rats in each of 4 groups: a cage-control group; an MX+ sham-RFR group; an MX + 0.3 W/kg RFR group; and an MX+ 0.9 W/kg RFR group. The animals were given MX continuously in their drinking water at a concentration of 19 µg/ml. The rats were exposed to RFR for 2 hours per day, 5 days per week, for 2 years. Blood samples were collected for genotoxicity studies after 3, 6 and 24 months of exposure. Liver and brain samples were obtained at the end of the experiment (24 months). The genotoxicity analyses were done by personnel blinded as to the origin of the samples. Blood samples were taken for these analyses from 20 randomly selected animals from each group. Genotoxicity was assessed by the alkaline comet assay and by examination for micronuclei. The liver and brain samples were also assessed by alkaline comet assay.
There was no evidence
of genotoxic activity of MX in blood and liver cells, but there was
in brain cells. Co-exposures to MX and RFR did not significantly increase
the response of blood, liver, and brain cells compared to MX exposure