THE ACTIVITY OF THE ISOLATED UTERUS

¹ From the Pharmacological Laboratory University College, London

1. The pendulum movements of the excised uterine horn of the virgin rabbit are not transmitted along the horn in the manner of a peristaltic wave but each part of the uterus contracts independently.

2. In the excised uterus of the pregnant or multiparous rabbit frequently the whole horn contracts simultaneously, but often different portions show independent activity.

3. The uteri of different virgin rabbits show considerable variations in their reaction to adrenalin.

4. After atropine adrenalin produces a well marked inhibition in the virgin rabbit's uterus.

5. Degenerative section of the nerves supplying the uterus slightly increases the automatic activity of the uterus and also slightly increases the response of the uterus to all drugs which cause increased contraction, whether these act on nerve endings like adrenalin, or on muscle like barium.

6. I have been unable to discover any nerve ganglion cells in the rabbit's uterus.

7. All parts of the rabbit's uterus, virgin, pregnant, or multiparous show automatic rhythmic contractions however small a piece is taken.

8. The circular muscle responds to drugs in every case in the same manner as the longitudinal muscle.

9. All the above facts suggest that the automatic activity of the uterus is of myogenic and not neurogenic origin.