Effects and mediated pathway of electrical stimulation of nucleus ambiguus on gastric motility and mucus secretion in rats.
BACKGROUND
It has been reported that nucleus ambiguus (NA) can regulate gastric motility. However, gastric motility is enhanced or inhibited after NA is excited, and reports have been inconsistent. Does NA affect gastric mucus secretion? This has been unreported up to now. We researched the effects of electrical stimulation of NA on gastric motility and mucus secretion in rats.


METHODS
The rats were divided into three groups. Group I, right NA was stimulated by four stimulation parameters. Group II, left NA was stimulated by the same parameters. The four stimulation parameters were 30 Hz 0.15 mA, 30 Hz 0.20 mA, 40 Hz 0.15 mA and 40 Hz 0.20 mA, and the width of all stimulation pulses was 0.30 ms. Group III, right NA was stimulated after the vagus nerves beneath the diaphragm were cut.


RESULTS
Electrical stimulations of both NAs significantly inhibited gastric motility, the right NA more so than the left. The results for group III show that the inhibitory effect of NA on gastric motility was withdrawn by vagotomy beneath the diaphragm.


CONCLUSIONS
NA inhibits gastric motility and the inhibitory degree of right NA is more than that of left NA. The inhibitory effect is mediated by vagus nerves. However, NA has no effect on gastric mucus secretion.
Wang
Y-H
YH
College of Life Sciences, Shandong Normal University, Jinan, Shandong Province, PR China.
Ai
H-B
HB
Zhang
Y-Y
YY
Cui
X-Y
XY
D000818:Animals; D004558:Electric Stimulation; D005753:Gastric Mucosa / Q000378:metabolism*; D005769:Gastrointestinal Motility / Q000502:physiology*; D006339:Heart Rate; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D009093:Mucus / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014628:Vagotomy; D014630:Vagus Nerve / Q000502:physiology