TREATMENT      MUTANT FREQUENCY (x 10-6)
2-nitrofluorene (µg/mL) NAT2(S)/GSTM1(+) NAT2(R)/GSTM1(-)
0 3.48 6.39
100 n.d. 12.6
200 3.95 26.8
400 4.95 30.5
500 1.98 n.d.
NAT2(S)/GSTM1(+):N-acetyltransferase 2 slow and glutathione S-transferase M1
positive
NAT2(R)/GSTM1(-):N-acetyltransferase 2 rapid and glutathione S-transferase M1
negative
n.d. = not determined due to low or excess cytotoxicity
Table 1: HPRT mutant frequency induced by various concentrations of 2-nitrofluorene in human peripheral lymphocytes with two different genotype combinations.