Abstract

Comparisons have been made between the effects of l-sparteine and oxytocin on isolated human uterine muscles. Both drugs can initiate spontaneous contractions and this effect is antagonized by addition of medroxyprogesterone to the fluid bath.

Neither l-sparteine nor oxytocin could initiate spontaneous contractions in muscles "polaized" in K₂SO₄-Ringer solution. These findings suggest that l-sparteine has its main action on membrane function rather than directly on the contractile elements of uterine muscle.