[Experimental gastro-esophageal reflux in rats].

: Aiming at developing a model of experimental gastro-esophageal reflux (GER) in the rodent we have tested three surgical procedures (distal esophageal myectomy (EM), esophago-gastrostomy (EG) and end-to-side esophago-jejunostomy (EJ) in three groups of 12 Wistar rats weighting 175 to 225 g. We have used for comparison a control group of unoperated rats. We have checked radiologically and by lower esophageal pH-monitoring that all three procedures induced GER and that this was absent in control animals. Six individuals in each group were sacrificed at the 7th day and the remaining six at the 14th day. At that time blood was drawn and esophageal tissue was collected for histological studies. Animals in the EM group were healthy after operation, had little vomiting and conserved their initial weight. Those in the EG and EJ groups had frequent vomiting, and lost weight. These symptoms were particularly severe in the EJ group. Animals in the control, EM and EG groups had histologically normal esophageal mucosa at the 7th and at the 14th days whereas those in the EJ group had grade 2-3 esophagitis at the 7th and grade 3 esophagitis at the 14th days. Esophageal epithelium in the rat is keratinized and therefore highly resistant to acid GER as attested by its excellent tolerance to reflux in the EM and EG groups. On the contrary, the presence of gastric and pancreatic juices and bile in the refluxate, like in the EJ group, digests the superficial layers of the epithelium and induces severe esophagitis.(ABSTRACT TRUNCATED AT 250 WORDS)