Relation of electrical activity to luminal transport in the cauda epididymidis of the rat in vitro.

Droplets of stained paraffin oil were injected into the lumen of the rat cauda epididymidis through a microcapillary in vitro at a mean distance of 36 /+- 8 cm from the beginning of the ductus deferens. The location of a droplet was marked on a 6-channel recorder graph after each event of electrical activity of the wall musculature. Transport of the droplets consisted of pendular movements. The droplet moved in the direction of the spread of electrical activity then returned almost to its original position during reflux. The net distance for transport was dependent on the direction of the spread of activity and on the percentage of the non-propagating activity. The mean probability for the spread of the electrical activity towards the ductus deferens between the pairs of the electrodes was 0.54 and the mean net transport was 6.2 /+- 1.8 )s.e.m.) mm/h, towards the ductus deferens in 7 out of 10 ducts.