Electroacupuncture improves restraint stress-induced delay of gastric emptying via central glutaminergic pathways in conscious rats.
Acupuncture has been used for treating functional gastrointestinal (GI) disorders. Animal studies demonstrated that acupuncture improves various stress-induced physiological responses. We investigated the effects of electroacupuncture (EA) at ST-36 (Zusanli; lower limb) on stress-induced delay of gastric emptying. Solid food gastric emptying in 90 min was significantly delayed by restraint stress (27.3 +/- 2.1%, n = 8), compared to that of controls (64 +/- 2.1%, n = 8). Restraint stress-induced delay of gastric emptying was significantly restored by the intracisternal (IC)-injection of GABA(A) receptor antagonist, bicuculline methiodide (46.5 +/- 3.1%; n = 6) and GABA(B) receptor antagonist, phaclofen (48 +/- 3.3%; n = 6). Delayed gastric emptying induced by restraint stress was significantly improved by EA at ST-36 (49.7 +/- 1.4%). The stimulatory effect of EA on stress-induced delay of gastric emptying was prevented by pretreatment with IC-injection of glutamate receptor antagonist, kynurenic acid (30.1 +/- 2.1%). In conclusion, restraint stress-induced delay of gastric emptying is mediated via central GABA(A) and GABA(B) receptors. EA at ST-36 stimulates glutaminergic neurons in the brainstem resulting in improvement of stress-induced delay of gastric emptying.
Iwa
Masahiro
M
Department of Surgery, Duke University and Durham Veterans Affairs Medical Center, Surgical Service 112, 508 Fulton Street, NC 27705, USA.
Nakade
Yukiomi
Y
Pappas
Theodore N
TN
Takahashi
Toku
T
D000818:Animals; D001418:Baclofen / Q000031:analogs & derivatives / Q000494:pharmacology; D001640:Bicuculline / Q000031:analogs & derivatives / Q000494:pharmacology; D015671:Electroacupuncture; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D005746:Gastric Emptying / Q000187:drug effects; D007736:Kynurenic Acid / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D011963:Receptors, GABA-A / Q000502:physiology; D018080:Receptors, GABA-B / Q000502:physiology; D017470:Receptors, Glutamate / Q000502:physiology*; D012149:Restraint, Physical; D013270:Stomach / Q000294:innervation; D013315:Stress, Psychological / Q000503:physiopathology*
D018691:Excitatory Amino Acid Antagonists; D058787:GABA-A Receptor Antagonists; D058788:GABA-B Receptor Antagonists; D011963:Receptors, GABA-A; D018080:Receptors, GABA-B; D017470:Receptors, Glutamate; C052329:phaclofen; C017069:bicuculline methiodide; D007736:Kynurenic Acid; D001418:Baclofen; D001640:Bicuculline