Lower Esophageal Sphincter Relaxation: Studies on the Neurogenic Inhibitory Mechanism
AUTOR(ES)
Tuch, Arthur
RESUMO
The purpose of this study was to determine the physiological mechanism of lower esophageal sphincter (LES) relaxation. Circular muscle of the esophagus, LES, and stomach were evaluated for their inhibitory response to electrical stimulation during a maintained tonic contraction produced by a superfusion of acetylcholine and physostigmine. Only the circular muscle of the distal esophagus showed an inhibitory response to electrical stimulation. The maximal inhibition of LES muscle was 63.9±5.9 (mean±SE)% of the acetylcholine produced tension and occurred at 80 V. Upper esophageal and gastric muscle were not inhibited. The inhibitory response of the LES muscle was antagonized by tetrodotoxin and hexamethonium but not by other specific antagonists. Adrenergic nerve destruction following 6-hydroxydopamine also did not abolish the LES inhibition. These data indicate that the distal esophagus, at the zone of the manometrically determined LES, is characterized by a nonadrenergic neural inhibitory system. We suggest that these nerves may mediate LES relaxation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=302222Documentos Relacionados
- Mechanics of Sphincter Action. STUDIES ON THE LOWER ESOPHAGEAL SPHINCTER
- Mechanism of the Lower Esophageal Sphincter Relaxation ACTION OF PROSTAGLANDIN E1 AND THEOPHYLLINE
- Mechanism of stretch-activated excitatory and inhibitory responses in the lower esophageal sphincter
- Mechanism of action of pentagastrin on the lower esophageal sphincter.
- Vasoactive intestinal polypeptide. A neurotransmitter for lower esophageal sphincter relaxation.
