The effects in myometrial preparations of D2343, a beta 2-adrenoceptor agonist possessing alpha 1-receptor blocking qualities

D2343 is a compound with about the same beta 2-adrenoceptor-agonist effect as terbutaline and exhibiting in addition an alpha 1-receptor inhibitory activity. D2343 has been compared to the beta 2-agonist terbutaline on oestrogenized uterine preparations from rat and rabbit (in vitro and in vivo) and in myometrial strips from homo. Generally, D2343 has shown an ability to relax the uterine muscles to the same degree as terbutaline or even more, especially when the two drugs were compared in vitro in preparations from rabbit and rat.