Functional affinities of α-1 AR antagonists estimated in the contractile responses to noradrenaline and NS-49 of rabbit ear artery Subtype selectivity, α-1AR subtype selectivity was listed. A, B, D, and L represent α-1A, -1B, -1D, and -1L AR subtypes, respectively. Slope, 95% CL: Schild slope and 95% confidence limits were listed. Data represent mean ± S.E.M. of 4 to 12 experiments.
Antagonist | Subtype Selectivity | Noradrenaline: pA2 or pKB (Slope, 95% CL) | NS-49: pKB (Slope, 95% CL) |
|---|---|---|---|
| Prazosin | A, B, D > L | 9.3 ± 0.1 (0.69,0.55–0.84) | 7.9 ± 0.1a(0.90,0.74–1.05) |
| Tamsulosin | A, D, L ≥ B | 9.6 ± 0.1 (0.66,0.54–0.90) | 9.9 ± 0.1 (0.87,0.56–1.18) |
| KMD-3213 | A, L > B, D | 7.3 ± 0.1 (0.81,0.57–0.95) | 9.3 ± 0.1a(0.92,0.75–1.09) |
| 5-Methylurapidil | A > D, L > B | 7.8 ± 0.1 (0.87,0.73–1.01) | 7.8 ± 0.2 (1.09,0.79–1.39) |
| RS-17053 | A > B, D, L | 6.3 ± 0.3b | 6.3 ± 0.3b |
| BMY 7378 | D > A, B, L | —c | —c |
↵ a p < 0.05, Significantly different from the value in the response to noradrenaline (Student's t test)
↵ b This pKB value was estimated at 1 μM RS-17053 by the concentration ratio method (Furchgott, 1972)
↵ c No inhibition at 1 μM BMY 7378