Gastroesophageal reflux triggers proliferative activity of the submucosal glands in the canine esophagus.

The effect of experimental gastroesophageal reflux on mitotic activity in the squamous epithelium, as well as in the submucosal glands, of the esophagus was investigated in dogs. The lower esophageal sphincter was destroyed in four dogs using a Wendel cardioplasty, a simple esophagotomy was carried out in four other animals, and four unoperated dogs were taken as controls. Two weeks later, mucosal samples from the esophagus were taken after in vivo labeling of the animals with bromodeoxyuridine. In all mucosal samples the proliferative parameters were estimated in the squamous epithelium, in the submucosal glands and in their excretory ducts. After the cardioplasty, the proliferative parameters were increased (P < 0.05) not only in the esophageal epithelium but also in the submucosal glands and in their excretory ducts (P < 0.05). The amplitude of the proliferative response was more than ten times larger in the latter than that in the surface epithelium. Gastroesophageal reflux is a potent proliferative stimulant to the esophageal squamous epithelium, but also to the cells of the submucosal esophageal glands and their excretory ducts.