Neural regulation of tone in the oesophageal body: in vivo barostat assessment of volume-pressure relationships in the feline oesophagus.
Recent combined manometric-barostat studies demonstrated that the oesophageal body exhibits both peristaltic contractions and tone. This study further characterized the neural modulation of tone in the feline oesophageal body. Simultaneous oesophageal barostat and manometry were performed in 20 adult cats under ketamine sedation. Oesophageal tone and peristalsis were assessed in the distal smooth muscle oesophagus. Cholinergic modulation was studied using neostigmine, erythromycin, atropine and vagotomy. Nitrergic regulation was assessed using sildenafil to increase cellular cyclic guanosine monophosphate and the nitric oxide synthase blocker Nomega-nitro-l-arginine (l-NNA). The presence of a tonic contractile activity in the distal oesophageal body was confirmed. Peristaltic contractions proceeded along the oesophageal body over the background tonic contraction. Neostigmine and erythromycin enhanced (20-30%) whereas bilateral vagotomy and atropine strongly decreased oesophageal tone (50-60%). However, l-NNA increased (40%) and sildenafil decreased oesophageal tone (30%). Therefore, tonic contractile activity in the oesophageal body is mainly caused by a continuous cholinergic excitatory input. A nitric oxide inhibitory mechanism may have a complementary role in the regulation of oesophageal tone.
Zhang
X
X
Centre for Gastroenterological Research, Catholic University of Leuven, Belgium.
Tack
J
J
Janssens
J
J
Sifrim
D A
DA
D000818:Animals; D002415:Cats; D018679:Cholinergic Agonists / Q000494:pharmacology; D018680:Cholinergic Antagonists / Q000494:pharmacology; D004947:Esophagus / Q000187:drug effects / Q000502:physiology*; D005260:Female; D008297:Male; D008365:Manometry; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D010528:Peristalsis / Q000187:drug effects / Q000502:physiology*; D014160:Transducers, Pressure; D014628:Vagotomy
D018679:Cholinergic Agonists; D018680:Cholinergic Antagonists; D009569:Nitric Oxide