(+)-Cyclazosin, a selective α1B-adrenoceptor antagonist: Functional evaluation in rat and rabbit tissues

In conclusion, these data confirmed that (+)-cyclazosin is a selective α1B-adrenoceptor antagonist also in functional assays, showing 13- and 38-fold selectivity for the α1B-adrenoceptor over α1A- and α1D-subtypes, respectively. Furthermore, (+)-cyclazosin displayed a significant selectivity for α1B-adrenoceptors relative to the α1L-subtype.