Effect of deamino-dicarba-oxytocin and oxytocin on myoelectrical and mechanical activity of uterus, stomach and small intestine in dog.

In conscious dog deamino-dicarba-oxytocin strongly stimulated a spike activity in the uterus which was more prolonged than that after oxytocin. Both oxytocin and deamino-dicarba-oxytocin inhibited the tone and peristaltic contractions of stomach and small intestines in starving dogs, eliminated the spike discharges, reduced the basic electrical rhythm frequency of the stomach and accelerated the propagation velocity of the slow waves in the small intestine. Only oxytocin, but not its deamino-analogue, reduced the pulse frequency and inhibited the spontaneous contractions of muscle strips isolated from the guinea pig stomach and portal vein.