Stereological studies on the rat small intestinal epithelium. II. Effects of antrectomy and antral exclusion.

Morphological studies were carried out on the absorptive cells of the small intestine to elucidate their reaction to shunt operations and to variations in endogenous gastrin production. Adult rats were subjected to 1) antrectomy with gastro-duodenostomy, 2) antrectomy with gastro-jejunostomy, 3) antral exclusion, or 4) sham operation. Quantitative light microscopy revealed no significant differences among the different groups with regard to the height of the absorptive cells and to the internal surface area of the duodenum or jejunum. In contrast, stereological measurements at electron-microscopical level demonstrated significant differences in the apical surface area of the absorptive cells. After antral exclusion or antrectomy with gastro-jejunostomy the apical surface area in the duodenal blind loop increased by 28% and 78%, respectively, in comparison to the sham-operated rats. A reduction of this area by approximately 30-40% was registered for the jejunal absorptive cells after antrectomy or antral exclusion. Hormone levels as well as intraluminal factors are presumably responsible for these variations in the brush-border surface area.