What is the secretory potential of submucosal mucous glands within the human gullet in health and disease?

Histology of the human esophageal mucosa reveals numerous submucosal mucous glands, scattered along the esophagus and especially accumulated below the upper and above the lower esophageal sphincters. Mucin remains a major organic component of human esophageal secretion, collected using our newly developed esophageal perfusion catheter. Esophageal mucin is accompanied by nonmucin proteins, epidermal growth factor (EGF) and prostaglandin E2 (PGE2). Bicarbonate is the major inorganic component of esophageal secretion in humans. Mucosal exposure to an HC1/pepsin solution, mimicking the natural gastroesophageal scenario, significantly changed the secretory profile of all esophageal secretion components. The rate of secretion of esophageal mucin, EGF and PGE2 under the impact of HC1/pepsin in patients with reflux esophagitis appeared to be significantly impaired, although the basal rate of esophageal PGE2 output remained higher than in controls. These data indicate that a significant impairment in esophageal components of the preepithelial mucosal barrier, paralleling the severity of mucosal inflammation, may have a detrimental impact on the protective potential of the esophageal mucosal barrier, facilitating the development of reflux esophagitis.