The effects of bile on the gastric mucosa.

Pure rat bile, mixed with an equal volume of 43% ethanol or distilled water, was intubated into the stomachs of fasted rats. Control rats were intubated with saline solutions or received no intraluminal solutions into the stomachs. Following a 10 min period of exposure of the bile or saline solutions to the luminal surface of the gastric mucosa, samples of the stomachs were processed for routine scanning and transmission electron microscopy and light microscopy. Observations indicated that the bile solutions produced extensive damage to the luminal surface of the stomach. The most prominent alteration was evident as a massive cytolysis of the epithelial cells which line the gastric glands, pits, and luminal surface of the gastric mucosa. Loss of the epithelium revealed the underlying honey-combed structure of the lamina propria. In addition, haemorrhagic areas were often observed throughout the mucosa. The findings of this study indicated that bile mixed with water or ethanol was highly destructive to the gastric epithelium, even more destructive than a solution of ethanol and water; however, the basal lamina and connective tissue fibres of the lamina propria were apparently unaltered by the bile solutions. Furthermore, the presence of an intact lamina propria in many areas where there was not extensive haemorrhage, following exposure of these solutions to the gastric mucosa, suggested the existence of a scaffolding structure for the proper orientation of the reconstruction process of epithelium of the glands, pits, and luminal surface of the altered gastric mucosa.