TABLE 3

Decay rate of several spin probes Values are indicated as mean ± S.D. Decay constant of later phase kβ was calculated for the concentration region between final concentration (at end time point) and 5-fold of final concentration. The end time point was at 6.5 min for amino-TEMPO, at 8 min for TEMPONE, at 10 min for TEMPOL, at 20 min for carboxy-TEMPO, and at 30 min for PROXYL group. Decay constant of initial phase kα was calculated for the concentration region between 10-fold of final concentration and 50% of predicted initial blood concentration after deduct second phase components. The prediction of initial blood concentration was calculated by blood volume as 7.78 ml/100 g b.wt. and total dose. Significance was estimated by Student's or Welch's t test.


Probes

High Dose (sub-MTD or 1.50 μmol/g)

Low Dose (half of high dose)
n
kα
kβ
n
kα
kβ
min-1 min-1
Carbamoyl-PROXYL 4 0.691 ± 0.057 0.067 ± 0.009 4 0.791 ± 0.119 0.061 ± 0.002
Carboxy-PROXYL 4 0.391 ± 0.043 0.080 ± 0.002 4 0.484 ± 0.104 0.076 ± 0.007
TEMPOL 4 1.511 ± 0.347 0.238 ± 0.070 4 2.383 ± 0.147a 0.195 ± 0.054
TEMPONE 4 1.584 ± 0.154 0.406 ± 0.064 4 1.752 ± 0.098 0.427 ± 0.043
Amino-TEMPO 4 2.878 ± 0.582 0.375 ± 0.016 5 3.066 ± 1.066 0.288 ± 0.053
Carboxy-TEMPO
4
0.696 ± 0.027
0.153 ± 0.031
4
0.809 ± 0.052a
0.146 ± 0.018
  • a Significance between high and low doses at P < 0.05