Gastric electrical stimulation with short pulses reduces vomiting but not dysrhythmias in dogs.
OBJECTIVE
The aim of this study was to investigate the acute effects of 3 different methods of electrical stimulation in the prevention of vasopressin-induced emetic response and gastric dysrhythmias.


METHODS
Seven female hound dogs chronically implanted with 4 pairs of electrodes on gastric serosa were used in a 5-session study. Saline and vasopressin were infused in sessions 1 and 2, respectively. In the other 3 sessions with vasopressin infusion, 3 different methods of electrical stimulation (short-pulse stimulation, long-pulse stimulation, and electroacupuncture) were applied. Gastric slow waves and vomiting and behaviors suggestive of nausea were recorded in each session. In a separate study, additional experiments were performed in 5 vagotomized dogs to investigate vagally mediated mechanisms.


RESULTS
Vasopressin induced gastric dysrhythmias, uncoupling of slow waves, and vomiting and behaviors suggestive of nausea (P < 0.02, analysis of variance). Long-pulse stimulation, but not short-pulse stimulation or electroacupuncture, was capable of preventing vasopressin-induced gastric dysrhythmias and gastric slow wave uncoupling. Short-pulse stimulation and electroacupuncture, but not long-pulse stimulation, prevented vomiting and significantly reduced the symptom scores, which was not noted in the dogs with truncal vagotomy.


CONCLUSIONS
Long-pulse stimulation normalizes vasopressin-induced slow wave abnormalities with no improvement in vomiting and behaviors suggestive of nausea. Short-pulse stimulation and electroacupuncture prevent vomiting and behaviors suggestive of nausea induced by vasopressin but have no effects on slow waves, and their effects are vagally mediated.
Chen
Jiande D Z
JD
Division of Gastroenterology, Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555, USA. jchen@utmb.edu
Qian
Liwei
L
Ouyang
Hui
H
Yin
Jieyun
J
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D004285:Dogs; D004599:Electric Stimulation Therapy / Q000379:methods*; D015671:Electroacupuncture; D004594:Electrophysiology; D005260:Female; D009325:Nausea / Q000523:psychology; D010507:Periodicity; D013270:Stomach / Q000187:drug effects / Q000502:physiology*; D013272:Stomach Diseases / Q000139:chemically induced / Q000517:prevention & control*; D014628:Vagotomy; D014667:Vasopressins / Q000494:pharmacology; D014839:Vomiting / Q000139:chemically induced / Q000517:prevention & control*
D014667:Vasopressins