Biomaterial Database

Modulation of lower esophageal sphincter relaxation in the opossum. 1979

J Fournet, and W J Snape, and S Cohen

The relationship of lower esophageal sphincter (LES) relaxation and sphincter pressure was studied in the basal state and after neurohumoral stimulation in the anesthetized opossum. LES relaxation was induced by electrical vagal stimulation, balloon distension, and swallowing, whereas LES pressure was increased by infusions of gastrin I, histamine, phenylephrine, or bethanechol. Each agent was selected to give an approximately twofold increase in LES pressure, at the highest dosage. The lower dosage gave a submaximal increase in LES pressure. Neither gastrin nor histamine modified sphincter relaxation as induced by vagal stimulation, esophageal distension, or swallowing. Phenylephrine or bethanechol made the LES less sensitive to vagal stimulation or esophageal distension without reducing maximal LES relaxation. Only bethanechol significantly decreased sphincter relaxation in response to swallowing (P less than 0.05). The results of this study suggest that LES relaxation is not a fixed response simply dependent on the inhibitory stimulus or the resting tonic level of LES pressure, but may be modulated by both alpha-adrenergic and cholinergic drugs.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009126	Muscle Relaxation	That phase of a muscle twitch during which a muscle returns to a resting position.	Muscle Relaxations,Relaxation, Muscle,Relaxations, Muscle
D009893	Opossums	New World marsupials of the family Didelphidae. Opossums are omnivorous, largely nocturnal and arboreal MAMMALS, grow to about three feet in length, including the scaly prehensile tail, and have an abdominal pouch in which the young are carried at birth.	Didelphidae,Opossum
D010656	Phenylephrine	An alpha-1 adrenergic agonist used as a mydriatic, nasal decongestant, and cardiotonic agent.	(R)-3-Hydroxy-alpha-((methylamino)methyl)benzenemethanol,Metaoxedrin,Metasympatol,Mezaton,Neo-Synephrine,Neosynephrine,Phenylephrine Hydrochloride,Phenylephrine Tannate,Neo Synephrine,Tannate, Phenylephrine
D003679	Deglutition	The act of taking solids and liquids into the GASTROINTESTINAL TRACT through the mouth and throat.	Swallowing,Deglutitions,Swallowings
D004943	Esophagogastric Junction	The area covering the terminal portion of ESOPHAGUS and the beginning of STOMACH at the cardiac orifice.	Gastroesophageal Junction,Gastroesophageal Junctions,Junction, Esophagogastric,Junction, Gastroesophageal,Junctions, Gastroesophageal
D005260	Female		Females
D005755	Gastrins	A family of gastrointestinal peptide hormones that excite the secretion of GASTRIC JUICE. They may also occur in the central nervous system where they are presumed to be neurotransmitters.	Gastrin
D006632	Histamine	An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.	Ceplene,Histamine Dihydrochloride,Histamine Hydrochloride,Peremin