Abstract: abstract:Objective To investigate the pathological and the expression of choline acetyltransferase(ChAT),vasoactive intestinal peptide(VIP),nitric oxide synthase(NOS) at lower esophageal sphincter(LES) against family dogs,which were operated on radiofrequency thermocoagulation(RFT).Methods A total of 15 dogs were randomly divided into three groups,Sham group:only underwent gastroscopy and feeding 3 months(n=5);RFT+24h group:feeding 24 hours after RFT(n=5);RFT+3m group:feeding 3 months after RFT(n=5). Observed the pathological of LES at 3 groups after HE staining,and the expression of ChAT, VIP and NOS by immunohistochemical method between Sham group and RFT+3m group.Results Sham group showed close to the normal tissue,RFT+24h group showed active inflammatory reaction and structural damage,RFT+3m group showed chronic inflammatory reaction and remodeling;Immunohistochemistry showed RFT+3m group compare with Sham group,ChAT were significantly increased,VIP,NOS were significantly decreased(all P<0.01).Conclusion After dogs operated by RFT,the thickness and pressure of LES were increasing，and expression of neurotransmitters in local tissue was changing.

Key words: gastroesophageal reflux, esophageal sphincter, lower, choline o-acetyltransferase, vasoactive intestinal peptide, nitric oxide synthase, dogs, 射频控温热凝术