Morphological changes caused by exposure of rabbit oesophageal mucosa to hydrochloric acid and sodium taurocholate.

Abstract

The present authors have studied the light and electron microscopic changes in rabbit oesophageal mucosa which has been exposed to solutions of hydrochloric acid and sodium taurocholate (ST). In an in vivo model the oesophagus was perfused with saline, acid (0.1-40 mmol/l of H+) or taurocholate (0.1-1.0 mmol/l at pH 2.0 or 1.0 mmol/l at neutral pH). At the end of each perfusion experiment the oesophagus was removed and assessed by the naked eye, light and electron microscopy. Some desquamation of superficial stratum corneum cells occurred in all specimens perfused for 5 h. Injury was more evident to the stratum spinosum and basal cell layers. Damage was more severe in the bile salt plus acid perfused specimens, varying between margination of nuclear chromatin in the basal cells to complete necrosis and separation of the overlying layers. Taurocholate in neutral solution did not damage the oesophageal epithelium. Electron microscopy revealed that damage to cells in the basal layers and stratum granulosum occurred within 30 min of exposure to acidified taurocholate, this damage increasing with time. It is concluded that taurocholate is able to damage oesophageal mucosa, that the damage first occurs in the deeper layers of the oesophageal mucosa and that the damage may occur in the absence of gross or light microscopic changes in the mucosa.