Scanning Electron Microscopic Studies on Biopsy Specimens of Human Duodenal Mucosa

[2] Ultrastructure of the Surface of Regenerating Epithelium in Duodenal Ulcer

Abstract

Fifty four patients with duodenal ulcer were included in the studies. The duodenalulcerations were divided endoscopically into three stages: active stage, 14 cases; healing stage, 28 cases; scar stage, 12 cases. Biopsy specimens obtained from marginal regions of theseulcers under fiberscopy were examined by a scanning electron microscope, HITACHI SSM-2 or HITACHI HHS-2R.
Regenerating epithelium in the active stage lacked villous structures, while they formedlow and swollen leaf-shaped villi in the healing stage, showing almost normal structures inthe scar stage. Immature epithelial cells constituting the regenerating epithelium were slightlyexpanded, having short and stunded microvilli sparsely on the cell surfaces. In some ofthem, peculiar shapes considered to be degenerative ones were observed on the surfaces.
Increase of numbers of goblet cells and heterotopic epithelial cells similar to gastric typecells, appearing in the specimens of both active and healing stages could be a protectionof the duodenal mucosa to prevent further inflammatory damages. Small cellular processesand top-end swollen microvilli like polyps were observed on the epithelial cell surfacessurrounding the ones of gastric type, suggesting that there could be at least two releasingmechanisms of mucosal secretion in an abnormal cellular condition during healing processof duodenal ulcers.