Canine gastric sling fibers: contractile properties.
The contractile properties of canine sling fibers and the longitudinal and circular muscles were characterized and compared. The longitudinal and circular muscles developed spontaneous contractions, but the sling fibers developed no spontaneous phasic contractions. The cholinergic receptors of all three muscles were excitatory. The alpha- and beta-adrenergic receptors of the longitudinal and circular muscles were inhibitory, but the sling fiber alpha-adrenergic receptors were excitatory and the beta receptors inhibitory. Large concentrations of atrophine induced contractions of all three muscles. Some of the contractile properties of the sling fibers are more similar to those of the distal esophageal circular muscle than to those of the gastric longitudinal and circular muscles. The sling fibers together with the esophageal circular muscle may play an important role in the gastroesophageal sphincter mechanism.
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004285:Dogs; D004943:Esophagogastric Junction / Q000187:drug effects / Q000502:physiology; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology*; D009388:Neostigmine / Q000494:pharmacology; D013270:Stomach / Q000502:physiology*; D013566:Sympathomimetics / Q000494:pharmacology
D013566:Sympathomimetics; D009388:Neostigmine; D001285:Atropine; D007545:Isoproterenol; D000109:Acetylcholine