The male ICR were divided into three groups in order to investigate the genotoxicological effects of various chlorophenol compounds in combination with N-nitrosodimethylamine.
The first group was the control group and only com oil was adminitered.
In the second group the chlorophenol compounds, 2-chlorophenol, 2.4-dichlorophenol. 2.4.6-trichlorophenol and pentachlorophenol were administered alone.
The mice were intraperitoneally injected with single doses varying from 50% to 6.25% of LD50 in each group.
In the third group, the same procedure was taken and dosage was repeated with an addition of 30mg/kg N-nitrosodimethylamine.
Twenty four hours later, the mouse thighbones were removed for microuncleus test. Among the 1,000 of PCE in bone marrow cells the MNPCE was counted and the PCE/NCE ratio were evaluated.
The results were as follows:
1) For the second group, the results differed slightly between various compounds : 2-chlorophenol was negative for all the varying doses on the micronucleus test. When the dosage was 50% of LD50, the PCE/NCE ratio in comparison with the control group was remarkably reduced. 2.4-dichlorophenol also tested negative and the PCE/NCE ratio was reduced. But the differences were not statisticaly significant.
2) 2.4.6-trichlorophenol and pentachlorophenol both tested positive when the LD50 was injected. And thd PCE/NCE ratio for pentachlorophenol was particularly reduced when 50% or 25% of the LD50 was injected.
3) In the third group 2-chlorophenol and 2.4-dichlorophenol reacted with an increase of micronuclei only when the LD50 was 50%. Again the PCE/NCE ratio was reduced and 2.4.6-tri-and pentachlorophenol reacted to all levels of dosage with an additive effect, and the increase of micronuclei was particularly remarkable at 50% fo LD50. Pentachlorophenol, at all levels of dosage, showed a reduced PCE/NCE ratio.
In conclusion, the chlorophenol, when raised to 50% of LD50 and administered with N-Nitrosodimethylamine, generally showed an increase of micronuclei.
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