Table 3

Comparison of the functional potencies of α1-adrenoceptor subtype-selective antagonists to inhibit noradrenaline-induced positive inotropic responses in rat left atria to the radioligand binding affinities at cloned α1-adrenoceptor subtypes expressed in HEK293 cells

npA2Slopeα1Aα1Bα1D
pKinHpKinHpKinH
RS-1705368.38  ± 0.030.55  ± 0.058.59  ± 0.080.8  ± 0.17.06  ± 0.091.1  ± 0.17.40  ± 0.111.1  ± 0.1
(+)-Niguldipine8.59  ± 0.140.8  ± 0.16.57  ± 0.100.8  ± 0.16.61  ± 0.111.0  ± 0.1
5-MU128.25  ± 0.180.75  ± 0.058.24  ± 0.110.8  ± 0.16.40  ± 0.130.7  ± 0.16.76  ± 0.140.8  ± 0.1
WB410188.42  ± 0.160.49  ± 0.059.28  ± 0.130.7  ± 0.17.29  ± 0.170.8  ± 0.18.42  ± 0.080.5  ± 0.1
BMY737886.80  ± 0.060.75  ± 0.066.11  ± 0.101.1  ± 0.16.40  ± 0.161.1  ± 0.18.29  ± 0.160.8  ± 0.1
Spiperone67.97  ± 0.110.74  ± 0.116.32  ± 0.130.7  ± 0.17.96  ± 0.241.0  ± 0.16.50  ± 0.080.9  ± 0.1
Prazosin69.86  ± 0.091.2  ± 0.209.34  ± 0.100.7  ± 0.19.16  ± 0.080.9  ± 0.059.69  ± 0.160.8  ± 0.0
Vohimbine47.00  ± 0.081.1  ± 0.156.09  ± 0.080.9  ± 0.045.54  ± 0.081.0  ± 0.056.18  ± 0.101.0  ± 0.0