Volumetric study on small intestine in newborn rat using design-based stereology technique

The small intestine continues from the pylorus to the cecum, and its main function is digestion and absorption of nutrients. Morphometric data of small intestine structures are related to its function. Therefore, in this study, the volume of the different layers forming the small intestine of the rat at birth in different segments has been calculated with stereology. A total of five newborn rats were used. The total volume of each segment was calculated by dividing the intestinal weight by its specific gravity. After systematic uniform random sampling of each segment of the small intestine, a point counting system place on the images of the tissue sections, then the relative volume of the tunica mucosa, tela submucosa and tunica muscularis was estimated. The total volume of the duodenum jejunum and ileum was ۰.۰۵۰۲±۰.۰۰۴۹۷ cm۳, ۰.۱۵۰۱±۰.۰۱۱۲۴ cm۳ and ۰.۰۲۱۳±۰.۰۰۲۷۹ cm۳, respectively. The fractional volume of the tunica mucosa was estimated as ۴۰.۷۷±۲.۵۵% in duodenum, ۵۴.۸۹±۲.۳۴% in jejunum and ۴۲.۲۴±۱.۸۷ % in ileum. The volume fraction of the tela submucosa was ۲۶.۸۹±۱.۲۶% in duodenum, ۲۲.۰۴±۱.۸۴% in jejunum and ۱۶.۲۳±۱.۲ % in ileum which indicated a significant difference between various segments of the small intestine (p<۰.۰۵). The tunica muscularis made up ۳۲.۳۳±۱.۴۷ %, ۲۳.۰۵±۲.۱۱ % and ۴۱.۵۱±۱.۳۸ % of the whole intestine in duodenum, jejunum and ileum, respectively. This parameter was also significant between intestinal segments (p<۰.۰۵). These quantitative data may provide a reliable reference value thus contributing to veterinary gastroenterology and to the experimental research on intestinal pathophysiology.

کلیدواژه ها:

Small intestine ، Stereology ، Volume ، Newborn ، Rat