Table 1. Nitroreductase activities in established tumours.
| Tumour type | Cytochrome P450 reductase (nmol min−1 mg−1) | Cytochrome b5 reductase (nmol min−1 mg−1) | DT-diaphorase (nmol min−1 mg−1) |
|---|---|---|---|
| RIF-1 | 2.21±0.18 | 50.0±1.8 | 1.38±0.23 |
| HT1080/26.6 | 3.39±0.36 | 36.8±1.4 | 0.93±0.01 |
| HT1080/1-3C | 4.15±0.34 | 35.3±2.5 | 0.21±0.05 |
| EMT6 | 2.79±0.37 | 52.2±1.9 | 0.62±0.15 |
| MCF-7 | 2.01±0.17 | 20.8±1.0 | 0.00±0.00a |
| P (ANOVA) | 0.001 | <0.001 | <0.001 |
Enzyme activities were determined spectroscopically by measuring reduction of cytochrome c at 550 nm, as described in Materials and Methods. Units are nmol of cytochrome c reduced per minute per mg of sample protein and are given as mean±s.e.m. (n=5–7).
a
No activity detected within effective range of assay (lower limit of detection=0.05 nmol min−1 mg−1).