HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 295/2/G389    most recent ajpgi.90201.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Sanmiguel, C. P. Articles by Soffer, E. E. Search for Related Content PubMed PubMed Citation Articles by Sanmiguel, C. P. Articles by Soffer, E. E.

NEUROREGULATION AND MOTILITY

Effect of electrical stimulation of the LES on LES pressure in a canine model

¹GI Motility Program and ²Minimally Invasive Surgery, Cedars-Sinai Medical Center, Los Angeles; ³Department of Electrical Engineering, University of Calgary, Calgary, Alberta, Canada and Department of Surgery, University of Alberta, Edmonton, Alberta, Canada

Submitted 20 February 2008 ; accepted in final form 24 June 2008

Gastric electrical stimulation modulates lower esophageal sphincter pressure (LESP). High-frequency neural stimulation (NES) can induce gut smooth muscle contractions. To determine whether lower esophageal sphincter (LES) electrical stimulation (ES) can affect LESP, bipolar electrodes were implanted in the LES of four dogs. Esophageal manometry during sham or ES was performed randomly on separate days. Four stimuli were used: 1) low-frequency: 350-ms pulses at 6 cycles/min; 2) high-frequency-1: 1-ms pulses at 50 Hz; 3) high-frequency-2: 1-ms pulses at 20 Hz; and 4) NES: 20-ms bipolar pulses at 50 Hz. Recordings were obtained postprandially. Tests consisted of three 20-min periods: baseline, stimulation/sham, and poststimulation. The effect of NES was tested under anesthesia and following IV administration of L-NAME and atropine. Area under the curve (AUC) and LESP were compared among the three periods, by ANOVA and t-test, P < 0.05. Data are shown as means ± SD. We found that low-frequency stimulation caused a sustained increase in LESP: 32.1 ± 12.9 (prestimulation) vs. 43.2 ± 18.0 (stimulation) vs. 50.1 ± 23.8 (poststimulation), P < 0.05. AUC significantly increased during and after stimulation. There were no significant changes with other types of ES. With NES, LESP initially rose and then decreased below baseline (LES relaxation). During NES, N^G-nitro-L-arginine methyl ester increased both resting LESP and the initial rise in LESP and markedly diminished the relaxation. Atropine lowered resting LESP and abolished the initial rise in LESP. In conclusion, low frequency ES of the LES increases LESP in conscious dogs. NES has dual effect on LESP: an initial stimulation, cholinergically mediated, followed by relaxation mediated by nitric oxide.

electrical stimulation; lower esophageal sphincter pressure; nitric; cholinergic; neural electrical stimulation