On the mechanism of action of ethodin in inducing myometrium contractions.

1. Ethodin (Rivanol, 6,9-diamino-2-oxyethyl acridine lactate), has been described as an effective drug to induce uterine contractions similar to those in a physiologic labor in still-birth with uterine inertia. We investigate the mechanisms involved in the effect of this compound in contracting the smooth-muscle cells of the myometrium to improve our understanding of the processes involved in the onset of labor. 2. We conclude that the contractile effect of ethodin is mediated through the activation of uterine mast cells that release mediators able to contract the myometrium.