ABSTRACT

Objective: The objective of this study is to investigate the development, growth, and maturation of the Brunner's glands, as well as their distribution in the duodenum of rabbits and mice. Methods: A total of 20 animals from each species were selected and categorized into four groups, with each group consisting of 5 animals. The categorization was based on the age of the animals in days, specifically One, Seven, Fifteen, and Forty. Samples were collected from various parts of the duodenum, and these samples were subsequently fixed using formalin and processed using histological techniques. The sections were stained using various techniques, including hematoxylin and eosin, Alcian blue PH 2.5, Periodic acid Schiff, a combination of Alcian blue and Periodic acid Schiff, and Masson's trichrome stains. In all studied species, the epithelium of the villi exhibited a substantial presence of vacuolated columnar cells at one day of age. The villi themselves were observed to be short and asymmetrical, with noticeable intervillus space. Additionally, the bases of the villi were characterized by clusters of immature cells, while the lamina propria lacked crypts. Furthermore, it was observed that the muscularis mucosa was not continuous. Furthermore, it was seen that the submucosa did not have a Brunner's gland. However, in mice at seven days of age and rabbits at ten days of age, the mucosa exhibited slender cylindrical villi and the muscularis mucosa had a poorly developed circular layer. During the histogenesis process, both crypts and Brunner's gland were observed to initiate their development. Results: Over a span of fifteen days, the presence of rabbits and mice resulted in a reduction in cell vacuolation. Additionally, the villi exhibited a mature morphology, while the crypts displayed evident growth. The muscularis mucosa acquired a circular layer, accompanied by an increase in the quantity of Brunner's gland within the submucosa. Conclusion: At the age of forty days, across various species, the mucosa exhibited mature villi with a leaf-like morphology. The crypts displayed a higher level of development, while the muscularis mucosa exhibited a well-developed circular muscular layer. In rabbits, the duodenal glands extended in close proximity to the jejunum, whereas these glands were absent in the latter segments of the mice duodenum. The glands in mice throughout their early developmental stages had serous characteristics, but the glands in rabbits displayed mucous characteristics. As rabbits age, the Brunner's glands in their digestive system exhibit a mixture of acini, whereas in mice, the majority of acini are mucous in nature. The aging process significantly influences the morphology of the villi, as well as the quantity of crypts and Brunner's glands. Furthermore, this study provides extensive morphometrical analyses that illustrate the alterations in the duodenal wall associated with aging.