Objective To observe the influence of electroacupuncture(EA) of "Zusanli"(ST 36) and ST 36 + "Neiguan"(PC 6) on gastric distention induced transient lower esophageal sphincter relaxation(TLESR) in cats.Methods Forty cats were randomly divided into model(gastric distension) group

EA-ST 36 group

EA-PC 6 group

EA-ST 36+PC 6 group

EA-non-acupoint group

EA-ST 36+saline(2mL i.v.) group

EA-ST 36+L-arginine(precusor of nitric oxide

200mg/kg i.v.) group

and EA-ST 36+Tacrine(cholinesterase inhibitor

5.6mg/kg i.p.) group

with 5 cats being in each group.TLESR model was established by extending the stomach with an air balloon.EA(2Hz/100Hz

3-4mA) was applied to bilateral ST 36

PC 6 and ST 36+PC 6 and non-acupoint(exterior-superior site of the hip) while gastric distension.L-Arginine was given 10min before EA

and Tacrine was given 30 min before EA.The frequency of TLESR and lower esophageal sphincter pressure(LESP) were recorded by using a perfused sleeve assembly.Results Compared with the model group

the frequency of TLESR in 60min as well as the percentage of common cavity during TLESR were significantly decreased in the EA-ST 36

EA-PC 6

EA-ST 36+PC 6

EA-ST 36+saline groups(P<0.05).Compared with the EA-ST 36+saline group

the frequency of TLESR in 60 min was up-regulated significantly in the EA-ST 36+Tacrine group(P<0.01) rather than in the EA-ST 36+L-Arginine group

suggesting a reduction of the efficacy of EA-ST 36 by cholinergic suppression(not by nitric oxide).No significant differences were found among the EA-ST 36

EA-PC 6 and EA-ST 36+PC 6 groups in the frequency of TLESR and the percentage of common cavity(P>0.05).In comparison with the baseline level

LESP was increased significantly only in the EA-ST 36 group(P<0.05).Conclusion EA at ST 36 can reduce both the frequency of TLESR and the percentage of common cavity during TLESR in gastric distension cats

which may be mediated by cholinergic pathway.