Published in:
01-08-2006 | Original Paper
Electroacupuncture Elicits Dual Effects: Stimulation of Delayed Gastric Emptying and Inhibition of Accelerated Colonic Transit Induced by Restraint Stress in Rats
Authors:
Masahiro Iwa, Yukiomi Nakade, Theodore N. Pappas, Toku Takahashi
Published in:
Digestive Diseases and Sciences
|
Issue 8/2006
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Abstract
Acupuncture has been used for treating functional gastrointestinal (GI) disorders. Animal studies have demonstrated that acupuncture antagonized various stress-induced responses. We investigated the effects of electroacupuncture (EA) at ST-36 (Zusanli; lower limb) on stress-induced alteration of GI motor activities. Solid gastric emptying was significantly delayed by restraint stress (29.6±2.4%; n=7) compared to that of controls (60.0±2.5%; n=8). Delayed gastric emptying was significantly improved by EA at ST-36 (47.2±1.8%). Intracisternal (IC) injection of corticotropin releasing factor (CRF; 1 μg) delayed gastric emptying to 25.4±3.1%, which was also improved by EA at ST-36, to 53.0±7.1% (n=8). The stimulatory effect of EA on stress-induced delayed gastric emptying was abolished by atropine (17.6±1.9%) but not by guanethidine (42.2±2.3%). Colonic transit was significantly accelerated by restraint stress (GC=7.2±0.3; n=8) compared to that of controls (GC=5.2±0.2; n=8). Accelerated colonic transit was significantly reduced by EA at ST-36 (GC=4.9±0.3). IC injection of CRF accelerated colonic transit (GC=6.9±0.2), which was also normalized by EA at ST-36 (GC=4.7±0.2). The inhibitory effect of EA on stress-induced acceleration of colonic transit was not affected by guanethidine (GC=4.6±0.3). In conclusion, EA at ST-36 showed dual effects: stimulation of stress-induced delayed gastric emptying and inhibition of stress-induced acceleration of colonic transit. The stimulatory effect of EA on stress-induced delayed gastric emptying is mediated via cholinergic pathways. The inhibitory effect of EA on stress-induced acceleration of colonic transit is independent of the sympathetic pathway.