Effects and mechanisms of gastrointestinal electrical stimulation on slow waves: a systematic canine study

Abstract

Sun Y, Song GQ, Yin J, Lei Y, Chen JDZ. Effects and mechanisms of gastrointestinal electrical stimulation on slow waves: a systematic canine study. Am J Physiol Regul Integr Comp Physiol 297: R1392-R1399, 2009. First published August 26, 2009 doi:10.1152/ajpregu.00006.2009.-The aims of this study were to determine optimal pacing parameters of electrical stimulation on different gut segments and to investigate effects and possible mechanisms of gastrointestinal electrical stimulation on gut slow waves. Twelve female hound-mix dogs were used in this study. A total of six pairs of electrodes were implanted on the stomach, duodenum, and ascending colon. Bilateral truncal vagotomy was performed in six of the dogs. One experiment was designed to study the effects of the pacing frequency on the entrainment of gut slow waves. Another experiment was designed to study the modulatory effects of the vagal and sympathetic pathways on gastrointestinal pacing. The frequency of slow waves was 4.88 Ϯ 0.23 cpm (range, 4 -6 cpm) in the stomach and 19.68 Ϯ 0.31 cpm (range, 18 -22 cpm) in the duodenum. There were no consistent or dominant frequencies of the slow waves in the colon. The optimal parameters to entrain slow waves were: frequency of 1.1 intrinsic frequency (IF; 10% higher than IF) and pulse width of 150 -450 ms (mean, 320.0 Ϯ 85.4 ms) for the stomach, and 1.1 IF and 10 -20 ms for the small intestine. Electrical stimulation was not able to alter colon slow waves. The maximum entrainable frequency was 1.27 IF in the stomach and 1.21 IF in the duodenum. Gastrointestinal pacing was not blocked by vagotomy nor the application of an ␣-or ␤-adrenergic receptor antagonist; whereas the induction of gastric dysrhythmia with electrical stimulation was completely blocked by the application of the ␣-or ␤-adrenergic receptor antagonist. Gastrointestinal pacing is achievable in the stomach and small intestine but not the colon, and the maximal entrainable frequency of the gastric and small intestinal slow waves is about 20% higher than the IF. The entrainment of slow waves with gastrointestinal pacing is not modulated by the vagal or sympathetic pathways, suggesting a purely peripheral or muscle effect.

Five-fold Gastrointestinal Electrical Stimulation With Electromyography-based Activity Analysis: Towards Multilocular Theranostic Intestinal Implants

“…However, only a few studies have investigated the effects of multilocular ES in multiple parts of the GI tract in animals or humans. [11][12][13] To address a broad spectrum of GI motility disorders as well as specific requirements of individual patients, interacting active implants distributed along the GI tract are needed. Multilocular sensing of GI activity will be the basis for adaptive modulation of complex physiological functions.…”

Prokinetic effects of spinal cord stimulation and its autonomic mechanisms in dogs

“…Gastric pace‐making activity was recorded by a special Biopac amplifier (Acqknowledge, EOG 100A; Biopac Systems, Inc Santa Barbara, CA) with a frequency range of 0.016‐30 Hz via the implanted serosal electrodes. The signal was offline analyzed using a special spectral analysis software package (Ningbo MedKinetic Inc, Ningbo, Zhejiang, China) and following parameters were derived: percentage of bradygastria (percentage of time during which the dominant frequency of the gastric slow wave was in the range of 0.5‐4.0 cycles/min (cpm), percentage of normal slow waves (4.0‐6.0 cpm) and the percentage of tachygastria (6.0‐12.0 cpm) . As seen in Figure , the gastric slow wave recording was of a high signal to noise ratio without major noises.…”

Gastrointestinal Electrical Neuromodulation for Functional Gastrointestinal Diseases, Obesity and Diabetes

“…Studies have shown that IES with long pulses (pulse width >50 ms) entrains intestinal slow waves and normalizes intestinal dysrhythmia (54). Whereas intestinal slow wave dysrhythmia can be reliably and consistently improved with IES or intestinal pacing, conventional IES with long pulses has not improved intestinal contractions.…”