Experimental study on changes of esophageal visceral sense stimulated by esophageal distention in rabbits and its mechanisms / 中华消化杂志

ABSTRACT

Objective To investigate the changes of esophageal visceral sence stimulated by esophageal distention in rabbits and the protein expressions of calcitonin gene related peptide(CGRP),P substance(SP),5-hydroxytryptamine(5-HT),Fos protein in central nervous system(CNS).Methods Twenty New Zealand rabbits were randomly divided into experimental group(n=8,received esophageal distention with 0.9 cm balloon for 30 s twice a day for 14 days),control group(n=6,received esophageal stimulation without balloon for 30 s twice a day for 14 days)and blank control grouop(n=6).The esophageal visceral sense was evaluated by animal behavior scores.The expressions of SP,CGRP,5-HT and Fos protein esophagus mucosa,spine,nucleus tractus solitari (NTS),periaqueductal gray(PAG)and thalamus were measured by immunochistochemistry.Results At the same behavior scores,the tube diameter of experimental group was significant lower than those of control group(P＜0.05).The expression of SP in esophagus mucosa,spine and NTS was significant increased in experimental group compared to two control groups(P＜0.05).The expression of CGRP and Fos in esophagus mucosa.spine,NTS,PAG and thalamus was increased in experimental group compared to two control groups(P＜0.05).The expression of 5-HT in esophagus mucosa and spine was higher in experimental group than that in control and blank control groups (esophagus 27.67±3.27 vs 11.00±1.79 or 11. 17±1.33;spine24.00±5.22 vs 11.33±2.94 or 11. 83±2. 48, P＜0. 01). But the expression of 5-HT in PAG was lower in experimental group( 13. 17±2.04) than that in control 17.67±2.07)and blank control (16.83±2.32) groups (P＜0. 05). There was significant correlation between CGRP and Fos, SP and Fos, CGRP and SP in spine (r=0. 813,0. 779,0. 772,P=0. 025,0.034, 0. 036, respectively). Conclusions Esophageal hypersensitivity may be induced by esophageal distention. The expresstion of SP, CGRP, 5-HT was increased in the esophageal mueosa and CNS, which indicate that these neurotransmitters and CNS may play an important role in the increase of esophageal visceral sense.