[Inhibition of uterine contractions by alpha adrenergic receptor blockaders]

In order to further investigate the adrenergic system of the pregnant uterus, the alpha 2-adrenoblocker Yohimbine and the alpha 1-alpha 2-blocker Phentolamine were examined in regard to their tocolytic effect on myometrial strips and compared with the relaxant effect of Prazosin which was already detected by our group. For both substances a highly significant decrease of uterine activity was found which did not differ from that of the alpha 1-blocker Prazosin.