Table 2.
Steroid specificity of [3H]PREG binding
| Steroid | RCR50 |
|---|---|
| PREG | 100 |
| PREGS | 78.8 ± 7.0 |
| Progesterone | 72.1 ± 17.7 |
| Δ5-Pregnene-3β,20α-diol | 68.4 ± 15.3 |
| 3β-Hydroxy-5α-pregnan-20-one | 18.4 ± 4.0 |
| Testosterone | 5.6 ± 2.8 |
| DHEA | 4.3 ± 2.6 |
| Estrone | 4.4 |
| Corticosterone | 2.8 |
| Androstenediol | 1.7 |
| Estradiol | 1.3 |
| Triamcinolone acetonide | 1 |
| 17α-Hydroxypregnenolone | 0.85 |
| 17α-Hydroxyprogesterone | 0.79 |
| DHEAS | 0.045 |
| Cholesterol | 0.02 |
A relative competition ratio (RCR) is expressed as (concentration of PREG over concentration of competitor) × 100, each of which produces a 50% decrease of specific [3H]PREG binding (mean ± SD; n = 3).