Effects of hindbrain stimulation on lower esophageal sphincter pressure in the cat

1984 ◽  
Vol 247 (1) ◽  
pp. G70-G78 ◽  
Author(s):  
F. C. Barone ◽  
D. M. Lombardi ◽  
H. S. Ormsbee

Lower esophageal sphincter (LES) pressure was measured in anesthetized cats during electrical stimulation of the dorsal motor nucleus of the vagus (DMV) and nucleus ambiguus (NA). Stimulation parameters were varied to determine maximal changes in LES pressure and upper gastrointestinal motor responses. LES pressure decreased significantly during DMV and NA stimulation. The LES preferentially was affected over other upper gastrointestinal locations. Bradycardia and increases in blood pressure occurred with stimulation of both nuclei. LES pressure changes could be demonstrated in the absence of other gastrointestinal responses by decreasing hindbrain stimulation parameters. Cervical vagotomy completely eliminated hindbrain stimulation-induced changes in LES pressure, upper gastrointestinal motor activity, and heart rate. Similar frequency-LES pressure response relationships were observed for DMV and NA stimulation, with maximum changes occurring at 25 Hz. Changes in LES pressure occurred at shorter stimulation pulses (0.05 vs. 0.5 ms) and at lower stimulating current strength (30 vs. 60 microA) during DMV as compared with NA stimulation. In addition, stimulation of areas adjacent to the DMV and NA also significantly altered LES pressure, indicating that a large portion of the cat hindbrain associated with the vagal motor nuclei is involved in LES pressure control.

2008 ◽  
Vol 294 (1) ◽  
pp. R121-R131 ◽  
Author(s):  
Mark Niedringhaus ◽  
Patrick G. Jackson ◽  
Stephen R. T. Evans ◽  
Joseph G. Verbalis ◽  
Richard A. Gillis ◽  
...  

The sphincter mechanism at the esophagogastric junction includes smooth muscle of the lower esophagus and skeletal muscle of the crural diaphragm (CD). Smooth muscle is known to be under the control of the dorsal motor nucleus of the vagus (DMV), while central nervous system (CNS) control of the CD is unknown. The main purposes of our study were to determine the CNS site that controls the CD and whether simultaneous changes in lower esophageal sphincter (LES) pressure and CD activity occur when this site is activated. Experiments were performed on anesthetized male ferrets whose LES pressure, CD activity, and fundus tone were monitored. To activate DMV neurons, l-glutamate was microinjected unilaterally into the DMV at three areas: intermediate, rostral, and caudal. Stimulation of the intermediate DMV decreased CD activity (−4.8 ± 0.1 bursts/min and −0.3 ± 0.01 mV) and LES pressure (−13.2 ± 2.0 mmHg; n = 9). Stimulation of this brain site also produced an increase in fundus tone. Stimulation of the rostral DMV elicited increases in the activity of all three target organs ( n = 5). Stimulation of the caudal DMV had no effect on the CD but did decrease both LES pressure and fundus tone ( n = 5). All changes in LES pressure, fundus tone, and some DMV-induced changes in CD activity (i.e., bursts/min) were prevented by ipsilateral vagotomy. Our data indicate that simultaneous changes in activity of esophagogastric sphincters and fundus tone occur from rostral and intermediate areas of the DMV and that these changes are largely mediated by efferent vagus nerves.


1990 ◽  
Vol 259 (6) ◽  
pp. G899-G906 ◽  
Author(s):  
C. D. Rossiter ◽  
W. P. Norman ◽  
M. Jain ◽  
P. J. Hornby ◽  
S. Benjamin ◽  
...  

Our purpose was to determine the central vagal sites for regulating changes in lower esophageal sphincter (LES) pressure in the cat. Injection of the retrograde tracer, horseradish peroxidase, into the LES resulted in labeling of cells in the dorsal motor nucleus of the vagus (DMV), with the largest number of cells appearing in two areas, one area rostral to obex (1.5-4.0 mm) and one area caudal to obex (-0.5 to -1.5 mm). In alpha-chloralose-anesthetized cats, L-glutamic acid was microinjected into these areas and LES pressure, intragastric pressure, and stomach motility were monitored. Microinjection of L-glutamic acid into the rostral area resulted in significant increases in LES pressure (18.6 +/- 4.9 mmHg; P less than 0.05), pyloric motility (baseline minute motility increased from 5.7 +/- 2.2 to 14.5 +/- 3.9 postinjection; P less than 0.05) and stomach pressure (baseline of 16.9 +/- 2.3 mmHg increased to 23.8 +/- 3.7 mmHg postinjection; P less than 0.05). Microinjection of L-glutamic acid into the caudal area resulted in significant decreases in LES pressure (-14.3 +/- 5.8 mmHg; P less than 0.05) and intragastric pressure (-7.5 +/- 2.2 mmHg; P less than 0.05) with no significant changes in pyloric motility. Ipsilateral vagotomy abolished both sets of responses. These data indicate that excitatory and inhibitory control of LES and intragastric pressure are mediated by vagal efferent neurons located in two distinct sites in the DMV.


1994 ◽  
Vol 39 (2) ◽  
pp. 381-384 ◽  
Author(s):  
Stanislas Chaussade ◽  
Spyros Michopoulos ◽  
Phillipe Sogni ◽  
Jean Guerre ◽  
Daniel Couturier

2019 ◽  
Vol 26 (19) ◽  
pp. 3497-3511 ◽  
Author(s):  
Teodora Surdea-Blaga ◽  
Dana E. Negrutiu ◽  
Mariana Palage ◽  
Dan L. Dumitrascu

Gastroesophageal reflux disease is a chronic condition with a high prevalence in western countries. Transient lower esophageal sphincter relaxation episodes and a decreased lower esophageal sphincter pressure are the main mechanisms involved. Currently used drugs are efficient on reflux symptoms, but only as long as they are administered, because they do not modify the reflux barrier. Certain nutrients or foods are generally considered to increase the frequency of gastroesophageal reflux symptoms, therefore physicians recommend changes in diet and some patients avoid bothering foods. This review summarizes current knowledge regarding food and gastroesophageal reflux. For example, fat intake increases the perception of reflux symptoms. Regular coffee and chocolate induce gastroesophageal reflux and increase the lower esophageal exposure to acid. Spicy foods might induce heartburn, but the exact mechanism is not known. Beer and wine induce gastroesophageal reflux, mainly in the first hour after intake. For other foods, like fried food or carbonated beverages data on gastroesophageal reflux is scarce. Similarly, there are few data about the type of diet and gastroesophageal reflux. Mediterranean diet and a very low carbohydrate diet protect against reflux. Regarding diet-related practices, consistent data showed that a “short-meal-to-sleep interval” favors reflux episodes, therefore some authors recommend that dinner should be at least four hours before bedtime. All these recommendations should consider patient’s weight, because several meta-analyses showed a positive association between increased body mass index and gastroesophageal reflux disease.


1985 ◽  
Vol 248 (4) ◽  
pp. G398-G406
Author(s):  
R. H. Holloway ◽  
E. Blank ◽  
I. Takahashi ◽  
W. J. Dodds ◽  
W. J. Hogan ◽  
...  

The opossum has served as a useful animal model for in vivo studies of lower esophageal sphincter (LES) function. Previous investigations, however, have been confined to studies on anesthetized animals. In 10 opossums we investigated LES pressure during fasting cycles of the gastrointestinal migrating myoelectric complex (MMC) and examined the influences of anesthesia and feeding on LES pressure. Intraluminal pressure from the esophageal body, LES, and gastric antrum was recorded by a manometric assembly that incorporated a sleeve device. Myoelectric activity was recorded from the gastric antrum and duodenum via implanted electrodes. MMCs were readily recorded from all animals. MMC cycle length was 86 +/- 2.9 (SE) min. The LES exhibited cyclic changes in intraluminal pressure that occurred in synchrony with the gastric MMC cycle. During phase I of the gastric MMC cycle, LES pressure was essentially stable, although intermittent spontaneous oscillations at 3-4/min were sometimes noted. Forceful phasic LES contraction started during phase II of the gastric MMC, became maximal during phase III, and disappeared during phase I. The MMC-related phasic LES contraction occurred at a maximal rate of 1.4 +/- 0.05/min with amplitudes of 60-150 mmHg and were temporally associated with spike bursts and contractions in the gastric antrum. Pentobarbital sodium-induced anesthesia abolished MMC-related phasic LES activity and caused a transient rise in basal sphincter pressure. Phasic LES activity was also inhibited by atropine and feeding.(ABSTRACT TRUNCATED AT 250 WORDS)


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