Effects of gastric pacing on gastric emptying and plasma motilin.
OBJECTIVE
To investigate the effects of gastric pacing on gastric emptying and plasma motilin level in a canine model of gastric motility disorders and the correlation between gastric emptying and plasma motilin level.


METHODS
Ten healthy Mongrel dogs were divided into: experimental group of six dogs and control group of four dogs. A model of gastric motility disorders was established in the experimental group undergone truncal vagotomy combined with injection of glucagon. Gastric half-emptying time (GEt(1/2)) was monitored with single photon emission computerized tomography (SPECT), and the half-solid test meal was labeled with an isotope-(99m)Tc sulfur colloid. Plasma motilin concentration was measured with radioimmunoassay (RIA) kit. Surface gastric pacing at 1.1-1.2 times the intrinsic slow-wave frequency and a superimposed series of high frequency pulses (10-30 Hz) was performed for 45 min daily for a month in conscious dogs.


RESULTS
After surgery, GEt(1/2) in dogs undergone truncal vagotomy was increased significantly from 56.35+/-2.99 min to 79.42+/-1.91 min (P<0.001), but surface gastric pacing markedly accelerated gastric emptying and significantly decreased GEt(1/2) to 64.94+/-1.75 min (P<0.001) in animals undergone vagotomy. There was a significant increase of plasma level of motilin at the phase of IMCIII (interdigestive myoelectrical complex, IMCIII) in the dogs undergone bilateral truncal vagotomy (baseline vs vagotomy, 184.29+/-9.81 pg/ml vs 242.09+/-17.22 pg/ml; P<0.01). But plasma motilin concentration (212.55+/-11.20 pg/ml; P<0.02) was decreased significantly after a long-term treatment with gastric pacing. Before gastric pacing, GEt(1/2) and plasma motilin concentration of the dogs undergone vagotomy showed a positive correlation (r=0.867, P<0.01), but after a long-term gastric pacing, GEt(1/2) and motilin level showed a negative correlation (r=-0.733, P<0.04).


CONCLUSIONS
Surface gastric pacing with optimal pacing parameters can improve gastric emptying parameters and significantly accelerate gastric emptying and can resume or alter motor function in a canine model of motility disorders. Gastric emptying is correlated well with plasma motilin level before and after pacing, which suggests that motilin can modulate the mechanism of gastric pacing by altering gastric motility.
Yang
Min
M
PLA, Research and Clinical Center for Gastroenterology, Southwest Hospital, Chongqing 400038, China.
Fang
Dian-Chun
DC
Li
Qian-Wei
QW
Sun
Nian-Xu
NX
Long
Qing-Lin
QL
Sui
Jian-Feng
JF
Gan
Lu
L
D000818:Animals; D004285:Dogs; D004599:Electric Stimulation Therapy; D005260:Female; D005746:Gastric Emptying; D018589:Gastroparesis / Q000097:blood / Q000503:physiopathology* / Q000628:therapy*; D008297:Male; D009037:Motilin / Q000097:blood*
D009037:Motilin