Binding characteristics of renal α2-adrenoceptors
| [3H]RX821002Kd25°C | PrazosinKi | Guanfacine Ki | |||
|---|---|---|---|---|---|
| nM | nM | nM | |||
| SBH (sham) | |||||
| Normal salt | 1.3 ± 0.2 | 33 ± 3 | 740 ± 120 | ||
| High salt | 1.6 ± 0.1 | 26 ± 4 | 1050 ± 400 | ||
| SBH (god) | |||||
| Normal salt | 1.3 ± 0.1 | 21 ± 4 (75–85%) | 1320 ± 160 | 20 ± 10 (15–25%) | 1200 ± 570 |
| High salt | 1.4 ± 0.2 | 18 ± 3 (72–83%) | 2300 ± 230 | 19 ± 5 (17–28%) | 1000 ± 400 |
| SBH (god+T) | |||||
| Normal salt | 1.5 ± 0.1 | 31 ± 3 | 970 ± 240 | ||
| High salt | 1.5 ± 0.2 | 37 ± 5 | 900 ± 150 | ||
K d25°C, equilibrium dissociation constant obtained from saturation curves (data not shown);K i, inhibition constants obtained from competition experiments (Fig. 2).
Data shown are mean ± S.E.M. (K d25°C values) or mean ± S.D. (K i values) of seven separate experiments. Each experiment was conducted in duplicate. In parentheses, relative proportions of high-affinity sites for each competitor.