Pharmacological analysis of the abomasum-rumen reflex in sheep.

Contractions of the dorsal sac of the rumen and abomasum were recorded in the sheep with chronic fistulae. It was found that during reflex inhibition of rumen contractions, induced with stimulation of chemoreceptors in the abomasum, an increased sympathicotonia plays an essential role and the beta-adrenergic receptors mediate the reflex.