Rat Treatment | n | T3 | T3 Receptor Occupancyb |
---|---|---|---|
ng/ml | % | ||
Control (12 h) | 2 | 0.80 ± 0.08 | 54 |
Control (24 h) | 2 | 0.87 ± 0.16 | 56 |
First T3 Injection | |||
12 h | 3 | 26.10 ± 2.70 | 97 |
24 h | 3 | 2.73 ± 0.46 | 80 |
36 h | 3 | 2.03 ± 0.19 | 75 |
Second T3 Injection | |||
12 h | 3 | 23.40 ± 3.40 | 97 |
24 h | 3 | 4.60 ± 0.70 | 87 |
36 h | 3 | 1.88 ± 0.14 | 74 |
Data are for the experiment shown in Fig. 2, using n rats per group. Vehicle-treated controls were killed 12 or 24 h after injection, as indicated. Plasma T3 levels of all six T3-treated rat groups were significantly higher than control (euthyroid) T3 levels (p < 0.0001; unpaired two-tailed t test). Nuclear occupancy of T3 receptors (q) was calculated from plasma T3 values according to Oppenheimer et al. (1977) using the equation q = p/(p + p1/2), where p is the measured plasma T3 concentration, and p1/2 = 0.67 ng/ml, the plasma T3 concentration at which T3 nuclear receptors are 50% occupied (Oppenheimer et al., 1977).