Effects and mechanisms of long‐pulse gastric electrical stimulation on canine gastric tone and accommodation

Abstract

Gastric electrical stimulation (GES) has been applied to treat gastroparesis and morbid obesity. The aims of this study were to evaluate the sites of stimulation and the mechanisms of GES on gastric tone and accommodation. Gastric tone and accommodation were evaluated with a barostat in surgically prepared dogs. GES was applied at seven different locations, and gastric tone was assessed at each site. The effect of truncal vagotomy on gastric tone and accommodation and the role of the nitrergic pathway were also evaluated. We have found: 1) GES induced varying degrees of gastric relaxation at all tested locations in normal dogs; 2) Gastric volume was also significantly increased with GES in vagotomized dogs and the change tended to be lower than that of normal animals; 3) Gastric accommodation was reduced during GES in both the normal and vagotomized dogs and the reduction tended to be more in the vagotomized animals; 4) The GES-induced increase in gastric volume was partially abolished by intravenous nitric oxide synthase inhibitor. GES at various sites of the stomach exerts inhibitory effect on gastric tone; the most effective sites are in the antrum along the lesser or greater curvature; the inhibitory effect of GES on gastric tone is partially mediated by the vagal and nitrergic pathway.

Inhibitory effects of desvenlafaxine on gastric slow waves, antral contractions, and gastric accommodation mediated via the sympathetic mechanism in dogs

“…The orientation of the gastric cannula was marked during surgery, when the abdomen was open, to ensure accurate placement of the barostat bag into the fundus. The catheter was connected to a computer-controlled electrical barostat device (Distender Series IIR; G & J Electronics, Willowdale, ON, Canada) (57). After its placement in the fundus, the bag was briefly inflated with 300 ml air and then completely deflated.…”

Retrograde gastric electrical stimulation suppresses calorie intake in obese subjects

“…Literature has shown that GES using pulse trains or long pulses at a width >1 ms can affect gastric motility by causing changes in the gastric slow wave, antral contraction, and gastric emptying (7,9,10). Such stimulation is called inhibitory GES (iGES).…”

“…The pulsed train was on for a period of 2 s and off for 3 s, with an output current of 10 mA at a frequency of 40 Hz. The pulse width was increased every 2 min at an increment of 1 ms with the maximum width less than 20 ms (9). RGES or sham stimulation was performed.…”

Inhibitory Effects of Gastrointestinal Electrical Stimulation on Rectal Tone are both Organ-Specific and Distance-Related in Dogs

“…1,5,7 Long-pulse GES is able to normalize gastric dysrhythmias, entrain gastric slow waves, accelerate gastric emptying, induce gastric relaxation, and inhibit rectal tone. 2,[6][7][8][9]16,[20][21][22][23] Long-pulse jejunal electrical stimulation is capable of accelerating intestinal transit in dogs and duodenum electrical stimulation is able to delay gastric emptying and reduce water intake in healthy humans. 11,17 CES with long pulses can significantly inhibit gastric tone and rectal tone.…”