[Characteristics of esophageal antiperistaltic activity in sheep]

Oesophageal motility was investigated in standing conscious sheep. A manometric method was used in four animals; two sheep, fitted with permanent electrodes at four levels, were used for oesophageal electromyography. The occurrence of retrograde peristalsis (mean speed 71,5 cm.s-1) at the beginning of every rumination cycle is reasserted. The characteristics of this activity are pointed out, with reference to normal peristalsis during the deglutition of saliva. Different types of stimulation have been compared. Retrograde peristalsis (mean speed 66 cm.s-1) can be triggered readily in non-ruminating animals by the association of two stimulations. One being oesophageal distension and the other injection of a solution prepared with some physical or chemical components of the rumen liquid. No specialized sensitive area could be demonstrated. However, facilitation is evident during reticular contractions. Retrograde waves of contraction always start from the terminal part of the thoracic oesophagus, whatever the level of stimulation.