Morphologic characteristics of esophageal epithelium in a rat model of duodenoesophageal reflux and protective effect of lafutidine

Backgrounds

The objectives of this study were to delineate differences in the morphologic characteristics of reflux esophagitis between a rat gastroesophageal reflux (GER) model and a duodenoesophageal reflux (DER) model and to evaluate the effects of H2-receptor antagonists on morphologic characteristics of reflux esophagitis in DER model.

Methods

Wistar rats were divided into 3 groups: GER model group (Group G), DER model group (Group D), and control group (Group C). Rats in each group were sacrificed 1 or 12 weeks after surgery. Intraesophageal pH was measured, and the excised esophagus was examined macroscopically and histologically. Subgroups of rats in Group D were given famotidine (10 mg/kg) or lafutidine (30 mg/kg) orally once daily for 1 week after surgery. The rats were then sacrificed, and histological findings were compared.

Results

Intraesophageal pH was significantly lower in Group G than in Group C. At 12 weeks, the epithelium of the lower esophagus in Groups G and D was significantly thicker than that in Group C and showed remarkable hyperplastic changes in Group D. The thickness of the epithelium in Group D + famotidine did not differ significantly from that in Group D. In contrast, the epithelium was significantly thinner in Group D + lafutidine than in Group D.

Conclusions

As a rat model of reflux esophagitis, DER causes severer damage to the esophageal epithelium, including hyperplastic changes, than does GER. Famotidine had no apparent effect on esophageal epithelial damage caused by DER, whereas lafutidine was suggested to attenuate such damage.