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Vagal Influences on the Phasic and Tonic Components of the Motility of the Ovine Stomach and Gastroduodenal Area
Author(s) -
Malbert Charles Henri,
Ruckebusch Yves
Publication year - 1989
Publication title -
neurogastroenterology and motility
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.489
H-Index - 105
eISSN - 1365-2982
pISSN - 1350-1925
DOI - 10.1111/j.1365-2982.1989.tb00140.x
Subject(s) - tonic (physiology) , vagotomy , stomach , vagus nerve , pylorus , abomasum , medicine , antrum , migrating motor complex , vagal tone , anatomy , biology , autonomic nervous system , stimulation , rumen , heart rate , food science , fermentation , blood pressure
Both the phasic and tonic components of gastric motility including the gastroduodenal junction were recorded after section or cooling blockade of the vagus nerves in conscious sheep. The phasic contractile activity was monitored using electromyography, strain gauges, and intraluminal manometry. The changes in the tone of the stomach (abomasum) were assessed by an electronic barostat. The cyclical contractions of the reticulorumen ceased immediately after bilateral vagotomy, whereas the activity of the antral part of the abomasum was strongly enhanced. Two weeks after vagotomy, the abomasal hypermotility persisted while reticuloruminal movements developed from a local nervous network. Vagal cooling at 5°C of one of the vagus nerves after section of the contralateral vagus similarly inhibited reticuloruminal contractions in contrast to the occurrence of abomasal hypermotility. During vagal cooling, both the abomasal and pyloric tone were lowered. We conclude that vagal cooling impairs excitatory input to the reticulorumen and inhibitory input to the gastroduodenal junction. The decreased smooth muscle tone at the abomasal and pylorus levels during vagal cooling suggests that vagal stimulatory influences are abated.