Comparative morphometric study on the duodenum of suckling, weanling and adult rats

Abstract
Introduction: Rat is considered to be one of the most suitable models for experimental studies regarding the physiology of digestion in rat and human. The scarce data on age-related changes in duodenal microstructure in healthy rats motivated us to perform this study.
Objectives: The current study elucidates morphometric changes of the thickness of the duodenal wall and its layers in immature and mature Wistar rats.
Material and Methods: The study was performed with male Wistar rats aged of 12 days, 1 months, 2 months, 3 month and 12 months. The duodenum was removed after the euthanasia of rats with xylazine and ketamine, placed in 10% aqueous formalin.
Results: Age dependent changes were established in the measured parameters: the thickness of the tunica mucosa and its sublayers, the thickness of the tela submucosa, tunica muscularis and the layer with duodenal glands, the diameter of duodenal glands, the depth and diameter of the glandule intestinales, the surface area and the width of the villi intestinales, the ratio of the number of intestinal crypts to the number of intestinal villi in suckling, weanling and adult rats. The length of the initial segment of duodenum containing duodenal glands was established for the first time. The age-related changes in the micromorphometric characteristics of the indicated microstructures established in our study complement the data available in the specialized literature on the histological structure of the wall of the duodenum in Wistar rats.
Conclusion: Original data on the age depending changes of the size of microstructural components of the normal duodenum in rats was provided, which can serve as reference values in various experimental studies related to digestive tract diseasesd, altered food availability, and other pathophysiological conditions.