Effect of Erythromycin on gastrointestinal motile function in young rabbits models with gastroesophageal reflux / 中华实用儿科临床杂志

ABSTRACT

Objective To establish the young rabbit models with gastroesophageal reflux (GER) and observe the effect of erythromycin in different parts of muscle segment (fundus ventriculi and lower esophageal),so as to investigate the variation after destroying the interstitial cells of Cajal (ICC).Methods Forty young rabbits of 8 weeks old were randomly divided into control group(n =20) and experimental group(n =20).In the experimental group,the fun dus ventriculus was partly ligated combined with helicobacter restriction at a level near the pylorus to establish GER young rabbit models.In the control group,the fundus ventriculi and pylorus were dissociated then the abdomen was closed.Four weeks later,10 rabbits from the experimental group and 10 rabbits from the control group were taken,2 lower esophageal segments and 2 fundus ventriculi muscle segments were split in each animal,and the ICC were destroyed at 1 lower esophageal segment and 1 fundus ventriculi muscle segment.The amplitude and frequency of lower esophageal and fundus ventriculi muscle segments were measured by using electrophysiology in vitro.Results (1) After 4 weeks of operation,the GER young rabbit models were successfully established.The data were detected by esophageal pH monitoring,general morphology observation and HE stain.Immunohistochemical staining of specific receptors protein c-kit on ICC showed that the ICC in the experimental group was reduced remarkably,and the morphological characteristics changed.(2) In the control group,the frequency and amplitude of lower esophageal muscle segments were (2.60 ± 0.70) times/min and (3.03 ± 0.59) g,the frequency and amplitude of fundus ventriculi muscle segments were (3.50 ± 0.97) times/min and (5.33 ± 1.09) g;in the experimental group,the frequency and amplitude of lower esophageal muscle segments were reduced to (0.29 ± 0.49)times/min and (0.61 ±0.43) g;the frequency of fundus ventriculi muscle segmens in the experimental group turned to (0.43 ± 0.54) times/min and the amplitude was (1.13 ± 0.41) g,and there were statistically differences compared with those of the control group (t =9.86,8.15,8.29,12.55,all P ＜ 0.05).(3) The influence of erythromycin in the lower esophageal and fundus ventriculi muscle segmentsthe amplitude after injecting erythromycin of lower esophageal muscle segments in the experimental group was (1.16 ± 0.83) g,the amplitude was significantly different (t =2.35,P ＜ 0.05),while the frequency had no relevance (P ＞0.05);the amplitude of fundus ventriculi muscle segments in the experimental group was (4.20 ± 1.14) g,and the difference was statistically significant(t =4.76,P ＜ 0.05),and there was no statistically more differences in the frequency (P ＞ 0.05).In the control group,the frequency and amplitude of lower esophageal muscle segments were (4.50 ±0.84)times/min and (5.13 ± 0.94) g,the frequency and amplitude of fundus ventriculi muscle segments increased to(5.40 ± 1.43) times/min and(7.50 ± 1.28) g,and the differences were statistically significant (t =3.79,5.78,3.06,6.45,all P ＜ 0.05).(4) The contraction activity of muscle segments after adding the erythromycin was prevented in the lower esophageal muscle segments or fundus ventriculi muscle segmens.Conclusions ICC plays an important role in the animal models of GER;erythromycin promotes the motility of the muscle segments in GER young rabbit models;in the sick models,erythromycin accelerates the gastrointestinal motility via ICC on muscle segments.