Control of stomach motility in the llama (Lama guanacoe f. glama).
Manometric and electromyographic recordings of stomach motility were made in five conscious llamas to investigate the influence of distension of the stomach compartments, of temporary cervical vagal blockade and the influence of atropine, acetylcholine and adrenaline. The frequency of A-contractions was slowed by distension of the canal joining compartment 2 (C2) and compartment 3 (C3), or of the proximal region of C3, and either increased and/or reduced by distension of the distal region of C3 or the hind stomach. The number of B-contractions in a cycle was increased according to the degree of distension of the cranial sac of compartment 1 (C1). B-contractions were also induced by distension of the canal or proximal region of C3 and were inhibited by distension of the distal region of C3 or the hind stomach. Contractions of C3 were not influenced by distension of C1 or C2 but were inhibited by distension of the canal, while distension within C3 caused a local excitation and an inhibition both proximal and distal to the point of stimulation. The hind stomach was only affected by local stimuli. Temporary vagal blockade abolished all contractions of C1, C2, and the canal and C3, but had little effect on the motility of the hind stomach. Infusion of atropine (0.01 mg/kg), acetylcholine (7-33 micrograms/kg . min) and adrenaline (0.3 micrograms/kg . min) inhibited motility in all stomach compartments except the hind stomach where acetylcholine was stimulatory. It is concluded that while the hind stomach may have intrinsic motility, the contractions of C1, C2, the canal and C3 of the llama stomach are dependent upon a vagal motor nerve supply and that the pattern of contractions observed is regulated at least partially according to the individual degree of distension of each of the stomach compartments.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001188:Artiodactyla / Q000502:physiology*; D001285:Atropine / Q000494:pharmacology; D001696:Biomechanical Phenomena; D002161:Camelids, New World / Q000502:physiology*; D004837:Epinephrine / Q000494:pharmacology; D005769:Gastrointestinal Motility / Q000187:drug effects; D009407:Nerve Block; D010812:Physical Stimulation; D013997:Time Factors; D014110:Touch / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology
D001285:Atropine; D000109:Acetylcholine; D004837:Epinephrine